Questions from Superinteressante (8-22-2011)

WEBVTT
Kind: captions
Language: en

00:00:00.526 --> 00:00:02.081
Sal Khan: This is Sal
Khan of the Khan Academy

00:00:02.081 --> 00:00:04.672
and I got these questions
from the Brazilian magazine,

00:00:04.672 --> 00:00:08.537
Superinteresante, and I
don't speak Portuguese

00:00:08.537 --> 00:00:10.929
that well but I assume it
means "super interesting"

00:00:10.929 --> 00:00:12.936
so I hope I can meet their standards

00:00:12.936 --> 00:00:14.830
and be at least somewhat interesting.

00:00:14.830 --> 00:00:16.538
Then sent me these
questions and I'm just going

00:00:16.538 --> 00:00:18.104
to give my best attempt to answer it.

00:00:18.104 --> 00:00:20.336
Question number 1, and
actually, let me use

00:00:20.336 --> 00:00:23.072
my pen tool Sal style
or Khan Academy style,

00:00:23.072 --> 00:00:24.751
to mark what question I'm on right now.

00:00:24.751 --> 00:00:26.333
Let's start with question number 1.

00:00:26.333 --> 00:00:29.416
Do you see Khan Academy
as a modern compliment

00:00:29.416 --> 00:00:32.737
to traditional education
or a resource that can be

00:00:32.737 --> 00:00:34.672
adapted without any other tool?

00:00:34.672 --> 00:00:37.000
Would that be the death of textbooks?

00:00:37.000 --> 00:00:38.340
First, let's take the first part

00:00:38.340 --> 00:00:40.475
because the second part's
a little controversial.

00:00:40.475 --> 00:00:42.403
Do you see Khan Academy
as a modern compliment

00:00:42.403 --> 00:00:44.114
to traditional education?

00:00:44.114 --> 00:00:45.829
Yes, I do.

00:00:45.829 --> 00:00:48.470
I think the ideal use
case for the Khan Academy

00:00:48.470 --> 00:00:52.136
is someone has an amazing teacher,

00:00:52.136 --> 00:00:54.751
and ideally amazing peers as well,

00:00:54.751 --> 00:00:57.543
and they can go to a physical environment

00:00:57.543 --> 00:00:59.404
and they can work with
their amazing teacher

00:00:59.404 --> 00:01:02.869
and amazing peers, and what
happens from our material

00:01:02.869 --> 00:01:04.557
is that they can watch
it at their own pace,

00:01:04.557 --> 00:01:06.224
do the exercises at their own pace,

00:01:06.224 --> 00:01:08.395
and they would get data on themselves

00:01:08.395 --> 00:01:11.001
and their awesome teacher
and peers will get data.

00:01:11.001 --> 00:01:13.803
Then they can use that
data to organize classrooom

00:01:13.803 --> 00:01:15.861
time in a more interactive
way so that everyone

00:01:15.861 --> 00:01:19.063
can really focus on helping
addressing everyone's problems.

00:01:19.063 --> 00:01:21.731
At least in our minds, it
really liberates the teacher

00:01:21.731 --> 00:01:25.062
to form lasting bonds and really mentor

00:01:25.062 --> 00:01:27.629
and work with and solve the problems

00:01:27.629 --> 00:01:30.594
that the students are
having with that material,

00:01:30.594 --> 00:01:33.327
and it allows the students
to teach each other.

00:01:33.327 --> 00:01:37.731
The second part of it, would
that be the death of textbooks?

00:01:37.731 --> 00:01:40.230
This is an interesting question.

00:01:40.230 --> 00:01:43.459
I guess it depends what you
view textbooks as being for.

00:01:43.459 --> 00:01:47.526
Right now I think in most
classes textbooks play two roles.

00:01:47.526 --> 00:01:51.065
One role is to introduce
you to the material

00:01:51.065 --> 00:01:54.337
with the idea that, in a
lot of classes I've been in,

00:01:54.337 --> 00:01:55.328
the professor would say,

00:01:55.328 --> 00:01:57.392
"Hey, why don't you go home,
do some of the reading,

00:01:57.392 --> 00:01:59.664
"that will be covered in lecture."

00:01:59.664 --> 00:02:03.125
For that use case, I
think on-demand video,

00:02:03.125 --> 00:02:05.478
whether it's Khan Academy
or other on-demand video,

00:02:05.478 --> 00:02:09.141
is better than a lot of the texts

00:02:09.141 --> 00:02:14.099
that can or cannot be
read by a lot of students.

00:02:14.099 --> 00:02:16.655
It's much easier to get
it through on-demand video

00:02:16.655 --> 00:02:17.846
than trying to parse through that text,

00:02:17.846 --> 00:02:19.922
especially when you're
unfamiliar with the concept.

00:02:19.922 --> 00:02:23.914
The other thing that a
textbook is for is practice.

00:02:23.914 --> 00:02:25.581
That's where a textbook
is really different

00:02:25.581 --> 00:02:27.252
than a traditional book is that it has

00:02:27.252 --> 00:02:30.947
these practice problems in it.

00:02:30.947 --> 00:02:34.125
What Khan Academy has is
practice problems as well,

00:02:34.125 --> 00:02:35.987
but we're collecting data on them.

00:02:35.987 --> 00:02:37.794
The teacher, the student
knows how they did,

00:02:37.794 --> 00:02:39.127
how long it took them,

00:02:39.127 --> 00:02:43.124
what they're having weakness
in or what they're strong in,

00:02:43.124 --> 00:02:45.196
and the student gets instant feedback.

00:02:45.196 --> 00:02:47.195
They know what they're understanding,

00:02:47.195 --> 00:02:48.691
they know what they're not understanding.

00:02:48.691 --> 00:02:52.111
They also get steps that we at least hope

00:02:52.111 --> 00:02:54.722
explain to the student where
they might have messed up;

00:02:54.722 --> 00:02:55.920
maybe they made a careless mistake

00:02:55.920 --> 00:02:58.331
or maybe got the conceptual error

00:02:58.331 --> 00:02:59.611
that they might have had trouble

00:02:59.611 --> 00:03:01.197
and of course it's all tied to the videos.

00:03:01.197 --> 00:03:03.920
Most textbooks right now
don't give that level

00:03:03.920 --> 00:03:06.852
of data to the student or to the teacher

00:03:06.852 --> 00:03:08.067
or the parents or anyone else,

00:03:08.067 --> 00:03:10.115
and they don't even
give that much feedback.

00:03:10.115 --> 00:03:11.814
They might have the answers
to half the questions

00:03:11.814 --> 00:03:12.751
in the back of the book.

00:03:12.751 --> 00:03:13.919
Some have a little bit more than that,

00:03:13.919 --> 00:03:15.491
but not much more.

00:03:15.491 --> 00:03:18.318
In those roles, we think
that on-demand video

00:03:18.318 --> 00:03:21.069
with self-paced software
with feedback and data

00:03:21.069 --> 00:03:24.253
can do a lot of those,
and it's even better

00:03:24.253 --> 00:03:27.320
when it's free and it
doesn't weigh ten pounds.

00:03:27.320 --> 00:03:28.860
With that said, I don't think textbooks

00:03:28.860 --> 00:03:31.123
are going to completely disappear.

00:03:31.123 --> 00:03:33.064
I think they're going to be
really useful as a reference.

00:03:33.064 --> 00:03:35.055
I have a bunch of textbooks
that I'm staring at

00:03:35.055 --> 00:03:36.860
right now on my shelf and I treasure them.

00:03:36.860 --> 00:03:40.383
I think they'll be a
really useful reference.

00:03:40.383 --> 00:03:43.693
It's not clear whether
you're going to have

00:03:43.693 --> 00:03:45.277
generations and generations of students

00:03:45.277 --> 00:03:48.259
having to buy the new
version of the textbook

00:03:48.259 --> 00:03:50.465
every few years, especially for subjects

00:03:50.465 --> 00:03:54.634
that are not changing on a regular basis.

00:03:54.634 --> 00:03:58.123
It's also clear physical textbooks

00:03:58.123 --> 00:04:01.113
are probably not going
to be the mainstream.

00:04:01.113 --> 00:04:02.714
There's already a lot of
people doing e-textbooks,

00:04:02.714 --> 00:04:04.917
but I assume that this
question is addressing

00:04:04.917 --> 00:04:06.412
e and physical textbooks.

00:04:06.412 --> 00:04:07.984
Question number 2:

00:04:07.984 --> 00:04:09.929
If children study at home

00:04:09.929 --> 00:04:11.663
and only go to school to do exercises,

00:04:11.663 --> 00:04:13.916
teachers' presence may
become less important.

00:04:13.916 --> 00:04:16.248
Would they have some
kind of a consultant role

00:04:16.248 --> 00:04:18.664
instead of being someone
who explains the concepts?

00:04:18.664 --> 00:04:21.787
I'll address the first part,
if children study at home

00:04:21.787 --> 00:04:23.252
and only go to school to do exercises,

00:04:23.252 --> 00:04:25.790
teachers' presence may
become less important.

00:04:25.790 --> 00:04:29.124
This is something that I'll
disagree strongly with.

00:04:29.124 --> 00:04:32.663
Imagine, if we were
doing it the other way,

00:04:32.663 --> 00:04:36.187
imagine if the world was
a world where when kids

00:04:36.187 --> 00:04:38.510
went to class, they had deep interactions

00:04:38.510 --> 00:04:40.718
with their peers and, more importantly

00:04:40.718 --> 00:04:43.188
or equally importantly, with the teacher,

00:04:43.188 --> 00:04:44.413
where they went to a class,

00:04:44.413 --> 00:04:45.510
the teacher knew who they were,

00:04:45.510 --> 00:04:47.409
the teacher knew everything
about the student,

00:04:47.409 --> 00:04:49.385
interacting with the student,
mentoring the student,

00:04:49.385 --> 00:04:52.062
the teacher knew exactly
what the tripping points

00:04:52.062 --> 00:04:55.725
were for the student,
how to phrase information

00:04:55.725 --> 00:04:57.655
specifically for that student,

00:04:57.655 --> 00:04:59.814
knowing what that student's context is,

00:04:59.814 --> 00:05:03.393
and then all of a sudden I
were to go into that classroom

00:05:03.393 --> 00:05:05.148
and say, no, teacher,
you have to stop doing

00:05:05.148 --> 00:05:07.191
this mentorship, this direct
one-on-one instruction

00:05:07.191 --> 00:05:09.794
with students, and what I
want you to do is not have

00:05:09.794 --> 00:05:11.150
these conversations with students anymore,

00:05:11.150 --> 00:05:12.929
and what I want you to do is
go to the front of the room

00:05:12.929 --> 00:05:15.398
and I want you to give these lectures

00:05:15.398 --> 00:05:17.395
that are essentially these one pace,

00:05:17.395 --> 00:05:18.732
one size fits all lecture.

00:05:18.732 --> 00:05:21.869
Really it'll be essentially
the same lecture that every

00:05:21.869 --> 00:05:23.350
teacher in the country's giving

00:05:23.350 --> 00:05:25.188
and that you've given years before.

00:05:25.188 --> 00:05:28.100
That would be making the
teacher less important

00:05:28.100 --> 00:05:30.475
because you would have
taken them as a human being,

00:05:30.475 --> 00:05:32.201
as someone who understands what's going on

00:05:32.201 --> 00:05:33.605
with the student, kind of the doctor

00:05:33.605 --> 00:05:35.205
for the student's knowledge,
and then you would be

00:05:35.205 --> 00:05:36.936
turning them into a broadcast mechanism.

00:05:36.936 --> 00:05:39.398
We're doing the exact opposite.

00:05:39.398 --> 00:05:41.017
Right now, unfortunately,
a lot of teachers

00:05:41.017 --> 00:05:42.207
want to be that mentor.

00:05:42.207 --> 00:05:43.742
A lot of the teachers
want to use class time

00:05:43.742 --> 00:05:46.138
for interaction and
creativity, but right now

00:05:46.138 --> 00:05:49.142
they have to move the entire
class at the same pace,

00:05:49.142 --> 00:05:51.395
and they have to give that lecture,

00:05:51.395 --> 00:05:55.206
many times with very little
interaction with the students.

00:05:55.206 --> 00:05:57.102
What we're saying is, no, that can happen

00:05:57.102 --> 00:05:59.691
at the student's own time and
at the student's own pace,

00:05:59.691 --> 00:06:02.842
and then the teacher just
becomes, every minute of time

00:06:02.842 --> 00:06:05.499
with the teacher just
becomes this valuable nugget.

00:06:05.499 --> 00:06:07.378
Several of the classes
that we're piloting,

00:06:07.378 --> 00:06:10.756
one of the teachers is making a point

00:06:10.756 --> 00:06:12.648
to spend 15 minutes one-on-one

00:06:12.648 --> 00:06:14.117
with every student per week, at least.

00:06:14.117 --> 00:06:16.722
I can remember years that I went by

00:06:16.722 --> 00:06:19.592
never getting 15 minutes
one-on-one with the teacher.

00:06:19.592 --> 00:06:20.847
That happens to many, many students.

00:06:20.847 --> 00:06:22.583
We think, if anything,
it's making the teachers

00:06:22.583 --> 00:06:23.982
far more important.

00:06:23.982 --> 00:06:25.915
They're forming bonds.

00:06:25.915 --> 00:06:27.922
They have to have a better grasp of all

00:06:27.922 --> 00:06:29.728
of the information now
because you have students

00:06:29.728 --> 00:06:30.943
working at their own pace.

00:06:30.943 --> 00:06:33.609
It's really taking them up the value chain

00:06:33.609 --> 00:06:34.991
because they're no longer giving

00:06:34.991 --> 00:06:37.468
the same lecture year in and year out.

00:06:37.468 --> 00:06:39.460
Then the second part of the question,

00:06:39.460 --> 00:06:41.397
would they have some
kind of a consultant role

00:06:41.397 --> 00:06:43.704
instead of being someone
who explains the concepts?

00:06:43.704 --> 00:06:45.394
What I would say is that they're still

00:06:45.394 --> 00:06:46.714
explaining the concepts, but they're

00:06:46.714 --> 00:06:49.270
explaining the concepts
given all of the information

00:06:49.270 --> 00:06:50.940
that they now have about the student.

00:06:50.940 --> 00:06:53.296
Given the fact that
that student has already

00:06:53.296 --> 00:06:56.702
maybe watched our videos,
has already done exercises,

00:06:56.702 --> 00:06:58.858
the teacher can now act on the data

00:06:58.858 --> 00:07:03.595
coming from those videos
and those exercises.

00:07:03.595 --> 00:07:06.725
Once again, I think the teacher
has moved up the value chain.

00:07:06.725 --> 00:07:08.460
They're now more valuable for that student

00:07:08.460 --> 00:07:10.460
than they were as a pure lecturer.

00:07:10.460 --> 00:07:12.398
Question number 3:

00:07:12.398 --> 00:07:14.295
When children have the freedom to study

00:07:14.295 --> 00:07:16.587
by themselves, at home,
surrounded by other appeals

00:07:16.587 --> 00:07:17.724
such as internet, social medial

00:07:17.724 --> 00:07:20.061
and also the possibility
to just ignore the lessons,

00:07:20.061 --> 00:07:24.330
isn't it too much confidence
in their passion for learning?

00:07:24.330 --> 00:07:26.191
Don't you think some
discipline is necessary

00:07:26.191 --> 00:07:29.190
to make them study instead
of doing anything else?

00:07:29.190 --> 00:07:30.901
There's a couple of
ways to think about it.

00:07:30.901 --> 00:07:34.060
Right now in a traditional classroom,

00:07:34.060 --> 00:07:35.993
you have mostly lecture going on,

00:07:35.993 --> 00:07:37.398
maybe with a little bit of other things,

00:07:37.398 --> 00:07:39.641
and then all of the problem solving,

00:07:39.641 --> 00:07:42.066
all of the homework, happens at home.

00:07:42.066 --> 00:07:45.133
I agree, some students might not have

00:07:45.133 --> 00:07:46.270
the motivation to do it at home,

00:07:46.270 --> 00:07:47.864
and we see a lot of kids
skipping the homework.

00:07:47.864 --> 00:07:49.434
Even the ones that do have the motivation

00:07:49.434 --> 00:07:50.350
might not have the help.

00:07:50.350 --> 00:07:53.407
So in my mind, where the
real learning happens

00:07:53.407 --> 00:07:55.767
is actually when you're trying
to do the problem solving.

00:07:55.767 --> 00:07:58.807
What's happening right
now is a lot of students

00:07:58.807 --> 00:08:00.731
are skipping out on the problem solving,

00:08:00.731 --> 00:08:01.866
on doing the homework,

00:08:01.866 --> 00:08:03.465
either because of distractions

00:08:03.465 --> 00:08:06.460
or because they have no one to help them.

00:08:06.460 --> 00:08:08.268
Then they all go to a room together

00:08:08.268 --> 00:08:10.350
where they're in the same room,

00:08:10.350 --> 00:08:12.069
but they're all passively
listening to a lecture.

00:08:12.069 --> 00:08:15.706
We think if you had to drop one thing

00:08:15.706 --> 00:08:19.533
from that equation, make sure
the problem solving occurs.

00:08:19.533 --> 00:08:22.644
Make sure that the teacher
sees students do problems.

00:08:22.644 --> 00:08:25.666
Don't put that out for homework where

00:08:25.666 --> 00:08:27.348
it may or may not happen.

00:08:27.348 --> 00:08:29.765
If you had to, and we
wouldn't advocate this,

00:08:29.765 --> 00:08:31.249
but we think if you had to pick

00:08:31.249 --> 00:08:32.850
between doing homework and lecture,

00:08:32.850 --> 00:08:35.129
which one do you skip, frankly
the lecture is, I think,

00:08:35.129 --> 00:08:36.387
the one that's more optional.

00:08:36.387 --> 00:08:37.852
In fact some students, and we've seen this

00:08:37.852 --> 00:08:39.323
in some of our pilots,
you show them enough

00:08:39.323 --> 00:08:41.792
examples or their peer can
teach them how to do something,

00:08:41.792 --> 00:08:43.876
they don't necessarily even
need to see the lecture.

00:08:43.876 --> 00:08:45.926
If they see a few examples
of it, that's enough.

00:08:45.926 --> 00:08:47.852
Maybe they'll go back
and watch the lecture

00:08:47.852 --> 00:08:51.653
for more depth or for more
intuition on the subject.

00:08:51.653 --> 00:08:55.594
With that said, on top
of that, we don't want

00:08:55.594 --> 00:08:57.792
to just completely let it
up to the student's judgment

00:08:57.792 --> 00:09:00.627
and have the teacher guessing
when they come to class

00:09:00.627 --> 00:09:02.159
the next day whether or not the student's

00:09:02.159 --> 00:09:04.379
watched lectures or did
some of the problems.

00:09:04.379 --> 00:09:06.322
That's why we're so focused on the data.

00:09:06.322 --> 00:09:08.056
That's why we're so focused on right now

00:09:08.056 --> 00:09:10.418
the teacher does get
a real-time dashboard.

00:09:10.418 --> 00:09:12.788
In a traditional classroom, the teacher

00:09:12.788 --> 00:09:14.001
just sees who turned in their homework

00:09:14.001 --> 00:09:15.587
or who did the homework,
and who knows if they

00:09:15.587 --> 00:09:16.717
copied it from another student.

00:09:16.717 --> 00:09:18.250
They don't know how long
it took the students

00:09:18.250 --> 00:09:20.089
to do the homework, whether
they got it right or wrong.

00:09:20.089 --> 00:09:22.531
They don't know what time of
day they did the homework.

00:09:22.531 --> 00:09:24.834
Now, the teacher will know everything.

00:09:24.834 --> 00:09:26.930
Now the teacher knows what
videos the student watched.

00:09:26.930 --> 00:09:28.530
Where did they even pause the videos?

00:09:28.530 --> 00:09:31.130
What videos did they have to repeat?

00:09:31.130 --> 00:09:34.511
They'll see the spread of where
every student in the class is.

00:09:34.511 --> 00:09:38.076
They'll see what problems
the kid actually did,

00:09:38.076 --> 00:09:41.137
how long it took them, when
they did those problems.

00:09:41.137 --> 00:09:43.002
Early on when I was doing
this, I saw one of my cousins

00:09:43.002 --> 00:09:44.875
was doing all of their
problems at 2 in the morning.

00:09:44.875 --> 00:09:46.668
That, by itself, was
probably more information,

00:09:46.668 --> 00:09:48.152
that they were awake at 2 in the morning,

00:09:48.152 --> 00:09:49.335
then the fact that they were even getting

00:09:49.335 --> 00:09:50.271
some of those problems wrong.

00:09:50.271 --> 00:09:51.744
That's something that a human being

00:09:51.744 --> 00:09:53.905
can then intervene in.

00:09:53.905 --> 00:09:56.180
Going back to the too much confidence, no.

00:09:56.180 --> 00:09:57.861
Now we're arming everyone
with a lot more data,

00:09:57.861 --> 00:10:01.431
so it's de-risking just
putting it all on the student

00:10:01.431 --> 00:10:02.526
to do everything at home.

00:10:02.526 --> 00:10:04.491
Question number 4:

00:10:04.491 --> 00:10:07.139
Let me scroll down a little bit.

00:10:07.139 --> 00:10:09.292
And the possibility to learn in your own

00:10:09.292 --> 00:10:12.391
wouldn't contribute to
isolate shy and misfit kids?

00:10:12.391 --> 00:10:14.256
Once again, complete opposite.

00:10:14.256 --> 00:10:16.207
Some people might be
surprised to hear this.

00:10:16.207 --> 00:10:17.716
I was actually very, very shy,

00:10:17.716 --> 00:10:19.714
especially in elementary
and to some degree

00:10:19.714 --> 00:10:22.717
in middle school, and I
felt very, very isolated

00:10:22.717 --> 00:10:23.623
in my classrooms.

00:10:23.623 --> 00:10:25.206
When I was in a classroom with 30 kids,

00:10:25.206 --> 00:10:28.271
even when I had a question, I
was afraid to raise my hand.

00:10:28.271 --> 00:10:30.458
I think this is true of
many, many, many kids.

00:10:30.458 --> 00:10:32.080
You don't want to embarrass
yourself raising ...

00:10:32.080 --> 00:10:33.789
It's usually the most outgoing kids

00:10:33.789 --> 00:10:35.407
who are willing to raise their hand,

00:10:35.407 --> 00:10:37.076
usually the two or three
most outgoing kids.

00:10:37.076 --> 00:10:39.338
I was never willing to do that.

00:10:39.338 --> 00:10:40.667
If I didn't understand something,

00:10:40.667 --> 00:10:42.436
I would just put it on myself to go home

00:10:42.436 --> 00:10:43.837
and try to struggle with it somehow.

00:10:43.837 --> 00:10:46.250
I had my sister who often
helped me with things.

00:10:46.250 --> 00:10:47.452
But I felt very isolated.

00:10:47.452 --> 00:10:52.315
Also, because I was shy,
there would be 30 kids

00:10:52.315 --> 00:10:53.582
in the room, but I really only knew

00:10:53.582 --> 00:10:56.318
maybe 5 of them well, maybe
because they sat near me.

00:10:56.318 --> 00:10:58.062
I would sit in class, and
this is even true in college.

00:10:58.062 --> 00:10:59.663
I used to sit in classes in college

00:10:59.663 --> 00:11:01.571
where there was 100 people in the room,

00:11:01.571 --> 00:11:02.649
and I only knew 2 of them.

00:11:02.649 --> 00:11:05.479
I would sit in that room
for the whole semester

00:11:05.479 --> 00:11:06.883
and I would never get to meet any of them

00:11:06.883 --> 00:11:08.721
the way that a traditional model works.

00:11:08.721 --> 00:11:10.719
And, frankly, the professor
never knew who I was.

00:11:10.719 --> 00:11:13.654
That even happened in
some of my elementary

00:11:13.654 --> 00:11:15.855
and middle school and high
school, where I don't really

00:11:15.855 --> 00:11:17.855
think the teacher knew who I was.

00:11:17.855 --> 00:11:19.852
What we're saying is the exact opposite.

00:11:19.852 --> 00:11:22.299
What we're saying is now
you're using the class time

00:11:22.299 --> 00:11:24.390
for the students to actually
interact with each other.

00:11:24.390 --> 00:11:26.855
If you look at these
pilots that we're running

00:11:26.855 --> 00:11:29.327
in Los Altos, you have all of the students

00:11:29.327 --> 00:11:31.137
interacting with all of the students.

00:11:31.137 --> 00:11:32.720
You don't have these little cliques

00:11:32.720 --> 00:11:34.057
where certain kids only hang out

00:11:34.057 --> 00:11:35.470
with other kids and ignore the rest;

00:11:35.470 --> 00:11:36.928
you have them all helping each other.

00:11:36.928 --> 00:11:39.852
It actually gives an
outlet for the shy kids,

00:11:39.852 --> 00:11:42.055
maybe the shy kids who
perform a little bit

00:11:42.055 --> 00:11:46.139
better academically, to
actually gain confidence

00:11:46.139 --> 00:11:48.523
by teaching their peers, their peers start

00:11:48.523 --> 00:11:50.188
to respect them more, not just as this

00:11:50.188 --> 00:11:51.968
shy kid who happens to do good at school,

00:11:51.968 --> 00:11:53.699
but, wow, that kid helped me.

00:11:53.699 --> 00:11:56.108
We're seeing way more interaction.

00:11:56.108 --> 00:11:58.254
There's no kid who's just
hiding during the lecture

00:11:58.254 --> 00:11:59.998
and just pretending to
understand the information.

00:11:59.998 --> 00:12:00.995
Everyone is interacting.

00:12:00.995 --> 00:12:02.230
The teachers are interacting
with the students.

00:12:02.230 --> 00:12:03.716
The students are
interacting with each other.

00:12:03.716 --> 00:12:05.254
So we think it's the exact opposite.

00:12:05.254 --> 00:12:06.998
We think we're taking the isolation that

00:12:06.998 --> 00:12:09.389
they shy kids are feeling right now

00:12:09.389 --> 00:12:11.325
and we're having them actually interact

00:12:11.325 --> 00:12:14.143
with each other in a human
experience in the classroom.

00:12:14.143 --> 00:12:15.520
Question number 5:

00:12:15.520 --> 00:12:17.725
Do you believe that some
old fashion thinkers

00:12:17.725 --> 00:12:20.122
just don't accept an education system

00:12:20.122 --> 00:12:24.416
that is supposed to be cool?

00:12:24.416 --> 00:12:27.049
Not 100% sure how to answer that question.

00:12:27.049 --> 00:12:29.099
I guess the assumption here is that what

00:12:29.099 --> 00:12:30.192
we're proposing is cool.

00:12:30.192 --> 00:12:31.821
I think it is.

00:12:31.821 --> 00:12:34.250
I think any time there's change,

00:12:34.250 --> 00:12:37.178
there will always be resistance,

00:12:37.178 --> 00:12:38.712
and I think that's a healthy thing.

00:12:38.712 --> 00:12:40.582
People should actively question things.

00:12:40.582 --> 00:12:42.317
No one should adopt something just

00:12:42.317 --> 00:12:45.774
because it's supposed to be cool

00:12:45.774 --> 00:12:47.000
or just because it sounds cool.

00:12:47.000 --> 00:12:48.851
You shouldn't just accept
it because it sounds cool,

00:12:48.851 --> 00:12:51.121
and you also shouldn't just
reject it because it sounds cool.

00:12:51.121 --> 00:12:54.245
The reality is that you really
should see whether it's working,

00:12:54.245 --> 00:12:55.715
and you should see whether it's working

00:12:55.715 --> 00:12:57.249
on multiple levels subjectively.

00:12:57.249 --> 00:12:59.172
How are the teachers and
the students liking it?

00:12:59.172 --> 00:13:00.665
How is the energy level?

00:13:00.665 --> 00:13:02.187
You should also look at it objectively.

00:13:02.187 --> 00:13:05.179
How is their performance changing?

00:13:05.179 --> 00:13:07.851
There definitely are knee-jerk
reactions against new things

00:13:07.851 --> 00:13:09.452
and there are knee-jerk
reactions for new things.

00:13:09.452 --> 00:13:13.004
Neither of those are the
best ways to approach it.

00:13:13.004 --> 00:13:14.457
You really should just have an open mind

00:13:14.457 --> 00:13:18.575
to anything and see if it really works.

00:13:18.575 --> 00:13:20.182
Question number 6:

00:13:20.182 --> 00:13:22.179
How has the acceptance to Khan Academy,

00:13:22.179 --> 00:13:23.961
I would assume, been in the United States?

00:13:23.961 --> 00:13:26.514
Has Bill Gates' support helped to open

00:13:26.514 --> 00:13:28.652
some conservative doors?

00:13:28.652 --> 00:13:30.783
We're still in the early days.

00:13:30.783 --> 00:13:34.052
Khan Academy, once again, it started as

00:13:34.052 --> 00:13:35.115
a very grassroots things.

00:13:35.115 --> 00:13:36.311
I started it for my cousins.

00:13:36.311 --> 00:13:39.846
It was adopted not because of a governor

00:13:39.846 --> 00:13:41.721
or the president told people to adopt it,

00:13:41.721 --> 00:13:42.787
or a superintendent did.

00:13:42.787 --> 00:13:45.263
It was adopted because
students chose to use it,

00:13:45.263 --> 00:13:47.259
students on their own,
students who happened

00:13:47.259 --> 00:13:49.317
to bump into it on the
internet found it useful.

00:13:49.317 --> 00:13:50.776
So it was a very grassroots thing.

00:13:50.776 --> 00:13:52.918
Only later, once we had
significant traction

00:13:52.918 --> 00:13:55.050
and I had been doing this for 5 or 6 years

00:13:55.050 --> 00:13:57.003
did it start to get on the radar of some

00:13:57.003 --> 00:13:59.806
fairly prominent people,
many of those who have

00:13:59.806 --> 00:14:02.141
supported us now, including Bill Gates

00:14:02.141 --> 00:14:05.971
and Google and others.

00:14:05.971 --> 00:14:06.913
In terms of the acceptance

00:14:06.913 --> 00:14:08.186
of the Khan Academy in the U.S.,

00:14:08.186 --> 00:14:12.445
the people who have chosen to
adopt it naturally like it.

00:14:12.445 --> 00:14:14.163
They have made the decision to use it.

00:14:14.163 --> 00:14:15.317
We haven't forced it on anyone else.

00:14:15.317 --> 00:14:16.664
I think that's a really important thing

00:14:16.664 --> 00:14:18.853
because I think when anyone
forces anything on anyone

00:14:18.853 --> 00:14:20.848
they tend to not like it.

00:14:20.848 --> 00:14:22.997
So far the acceptance has been very good

00:14:22.997 --> 00:14:25.914
and we've had really
fascinating experiences

00:14:25.914 --> 00:14:27.784
and tremendous results with
the pilots that's chose

00:14:27.784 --> 00:14:29.918
to adopt it if we talk
about the formal setting.

00:14:29.918 --> 00:14:31.451
If you're thinking about
the informal setting,

00:14:31.451 --> 00:14:32.994
the students who are just
using it independently,

00:14:32.994 --> 00:14:34.990
I encourage anyone to
go to our YouTube page

00:14:34.990 --> 00:14:41.115
or our Facebook page and
just read the commentary

00:14:41.115 --> 00:14:43.914
from students, and even
ask them questions,

00:14:43.914 --> 00:14:46.582
contact them, and see how it's helped them

00:14:46.582 --> 00:14:48.993
and I think you'll see,
at least we like to think,

00:14:48.993 --> 00:14:51.916
it's profoundly effecting
a lot of students

00:14:51.916 --> 00:14:53.744
in the U.S., and the world, frankly.

00:14:53.744 --> 00:14:55.854
The question has Bill
Gates' support helped

00:14:55.854 --> 00:14:57.409
to open some conservative doors?

00:14:57.409 --> 00:14:59.555
You know, I think that's a mixed answer.

00:14:59.555 --> 00:15:01.611
I think it's definitely given validation

00:15:01.611 --> 00:15:02.665
within certain circles.

00:15:02.665 --> 00:15:04.803
I think people in Silicone
Valley really respect

00:15:04.803 --> 00:15:08.202
that Google is behind us,
Bill Gates is behind us.

00:15:08.202 --> 00:15:10.466
These are obviously groups and people

00:15:10.466 --> 00:15:12.000
who are obviously intelligent,

00:15:12.000 --> 00:15:13.469
who've obviously been successful,

00:15:13.469 --> 00:15:15.283
who obviously understand
what a math and science

00:15:15.283 --> 00:15:19.817
education is for, who are
almost the examples of ...

00:15:19.817 --> 00:15:22.211
The people at Google understand there's

00:15:22.211 --> 00:15:24.333
no better application of math and science

00:15:24.333 --> 00:15:25.302
than what Google has done

00:15:25.302 --> 00:15:26.128
or what Bill Gates has done

00:15:26.128 --> 00:15:27.961
or what other people in
Silicone Valley have done.

00:15:27.961 --> 00:15:30.125
That's definitely validation.

00:15:30.125 --> 00:15:31.760
Whether it opens conservative doors or not

00:15:31.760 --> 00:15:34.865
is not clear because I
think Bill Gates has also

00:15:34.865 --> 00:15:36.344
been doing other things.

00:15:36.344 --> 00:15:38.749
He's very active in the Charter movement.

00:15:38.749 --> 00:15:42.481
He's been pushing for other things.

00:15:42.481 --> 00:15:45.079
There are some people
who react against that

00:15:45.079 --> 00:15:50.137
and they might be tempted
to throw us in the same bag.

00:15:50.137 --> 00:15:53.327
Us, personally, we try not
to take an opinion on that.

00:15:53.327 --> 00:15:58.098
We want to be useful for
anyone, in any organization.

00:15:58.098 --> 00:15:59.981
We're not taking a political stance there

00:15:59.981 --> 00:16:02.389
but I think because Bill Gates really is

00:16:02.389 --> 00:16:04.676
one of our biggest supporters,

00:16:04.676 --> 00:16:07.588
some groups are more receptive to it

00:16:07.588 --> 00:16:09.653
and some groups are less receptive to it.

00:16:09.653 --> 00:16:13.582
Overall, I definitely think
it's been a huge positive

00:16:13.582 --> 00:16:15.123
because I think the
parents and the students

00:16:15.123 --> 00:16:20.126
view it as a huge plus when
someone whom they respect

00:16:20.126 --> 00:16:22.208
think so highly of it and uses it himself

00:16:22.208 --> 00:16:25.062
and uses it for his kids.

00:16:25.062 --> 00:16:27.703
Question number 7:

00:16:27.703 --> 00:16:29.542
Has Khan Academy ever been contacted

00:16:29.542 --> 00:16:31.392
by some Brazilian school or company

00:16:31.392 --> 00:16:34.591
interested in adopting its methods?

00:16:34.591 --> 00:16:36.795
I can't say no totally.

00:16:36.795 --> 00:16:38.598
We've had a lot of contact
with people from Brazil

00:16:38.598 --> 00:16:40.763
and we are actively
translating the video content

00:16:40.763 --> 00:16:44.529
to Portuguese, so we've
had contact with Brazil.

00:16:44.529 --> 00:16:46.393
We're not doing any
formal pilots in Brazil.

00:16:46.393 --> 00:16:49.271
I wouldn't be surprised if
some students or teachers

00:16:49.271 --> 00:16:50.685
are using it independently.

00:16:50.685 --> 00:16:52.269
In fact, I'm sure some students are.

00:16:52.269 --> 00:16:54.860
Teachers can use what
we're doing in Los Altos

00:16:54.860 --> 00:16:56.401
on their own, but we don't have any formal

00:16:56.401 --> 00:16:58.737
pilots in Brazil right now.

00:16:58.737 --> 00:17:01.114
Question number 8:

00:17:01.114 --> 00:17:03.910
Besides the positive testimonies
from Los Altos' teachers,

00:17:03.910 --> 00:17:05.528
do you have some numbers
that could measure

00:17:05.528 --> 00:17:08.383
how Khan Academy has
helped students to develop?

00:17:08.383 --> 00:17:10.068
Some numbers that could help us compare

00:17:10.068 --> 00:17:13.087
traditional education to
your system's performance.

00:17:13.087 --> 00:17:16.258
The simple answer is,
yes, we do have numbers.

00:17:16.258 --> 00:17:19.525
This is why Los Altos has decided to go

00:17:19.525 --> 00:17:22.716
district-wide with this
in the 5th and 6th grade.

00:17:22.716 --> 00:17:24.053
Actually, let me pause the video

00:17:24.053 --> 00:17:25.756
and let me get you some of those numbers.

00:17:25.756 --> 00:17:27.125
Hold on one second.

00:17:27.125 --> 00:17:29.528
You asked for data, so
here's data that I got.

00:17:29.528 --> 00:17:32.581
We have other data, but
this one piece of data

00:17:32.581 --> 00:17:33.796
is probably the most compelling

00:17:33.796 --> 00:17:35.557
that really convinced Los Altos.

00:17:35.557 --> 00:17:36.664
It's not a rigorous study.

00:17:36.664 --> 00:17:38.993
We're going to be doing more
rigorous studies this year

00:17:38.993 --> 00:17:42.134
with larger data sets and
in a more controlled way,

00:17:42.134 --> 00:17:44.067
but we obviously had all of the anecdotal

00:17:44.067 --> 00:17:46.895
higher energy in the classroom,
kids were more engaged,

00:17:46.895 --> 00:17:49.148
the teachers loved it, but
we wanted to see real data.

00:17:49.148 --> 00:17:52.004
This is actually what we saw
out of the 7th grade pilot.

00:17:52.004 --> 00:17:53.725
I want to be clear,
these 7th grade classes

00:17:53.725 --> 00:17:56.561
were considered developmental classes,

00:17:56.561 --> 00:17:59.228
kids that weren't tracked
with the normal students;

00:17:59.228 --> 00:18:01.531
they were held back, they weren't
performing at grade level.

00:18:01.531 --> 00:18:03.403
This shows how they performed

00:18:03.403 --> 00:18:08.825
at their district
standardized exam in 2010.

00:18:08.825 --> 00:18:11.821
You can see that the best students here,

00:18:11.821 --> 00:18:14.937
you had 23 that were proficient,

00:18:14.937 --> 00:18:16.740
then you had 47 that were basic,

00:18:16.740 --> 00:18:18.601
23 that were below basic,

00:18:18.601 --> 00:18:21.468
and then you had 6 that
were far below basic.

00:18:21.468 --> 00:18:22.757
Don't get this light blue confused

00:18:22.757 --> 00:18:23.839
with this dark blue over here

00:18:23.839 --> 00:18:25.187
because they're saying
very different things.

00:18:25.187 --> 00:18:27.389
This is far below, so
this right over here,

00:18:27.389 --> 00:18:31.183
they're not doing well,
far below basic, this 6.

00:18:31.183 --> 00:18:33.638
The same students,
after doing Khan Academy

00:18:33.638 --> 00:18:35.058
for about 6 or 7 months,

00:18:35.058 --> 00:18:37.367
and once again it's hard
to separate how much ...

00:18:37.367 --> 00:18:39.820
Courtney Caldwell, who's the teacher here

00:18:39.820 --> 00:18:41.804
is just an off the charts awesome teacher

00:18:41.804 --> 00:18:45.421
so it might be due to her
as well, what we've seen.

00:18:45.421 --> 00:18:47.589
She herself expressed
that the energy level

00:18:47.589 --> 00:18:49.255
that she saw in the class is very unusual

00:18:49.255 --> 00:18:52.128
for especially a class that is at this

00:18:52.128 --> 00:18:53.688
developmental stage.

00:18:53.688 --> 00:18:57.042
These are the results from
this year's standardized exams.

00:18:57.042 --> 00:19:00.329
There's no longer any
students in this group

00:19:00.329 --> 00:19:02.072
that are far below basic.

00:19:02.072 --> 00:19:04.493
In fact, there are now 6
kids that are advanced.

00:19:04.493 --> 00:19:06.931
Just to be clear, these
are kids that have, now,

00:19:06.931 --> 00:19:10.495
leapfrogged their peers who
are not placed in this class.

00:19:10.495 --> 00:19:13.457
Normally when you're
tracked into a slower class,

00:19:13.457 --> 00:19:15.255
that's usually the end
of your math career.

00:19:15.255 --> 00:19:16.943
You're usually just going
to drift further and further

00:19:16.943 --> 00:19:18.068
behind the other students.

00:19:18.068 --> 00:19:21.740
These students after half
a year actually did better

00:19:21.740 --> 00:19:24.398
than many students who weren't
placed into the slower class.

00:19:24.398 --> 00:19:26.316
Then you have many, many more students

00:19:26.316 --> 00:19:27.523
who are now proficient.

00:19:27.523 --> 00:19:30.334
The basic, you still have 47, but you have

00:19:30.334 --> 00:19:31.810
so many more who are
proficient or advanced.

00:19:31.810 --> 00:19:34.731
Then you have no students
that are far below basic.

00:19:34.731 --> 00:19:37.602
In 12% of the pilot, students
moved from below basic

00:19:37.602 --> 00:19:43.735
to proficient, and 6% moved
from far below basic to basic.

00:19:43.735 --> 00:19:49.398
There's a general trend where
people just moved forward.

00:19:49.398 --> 00:19:50.643
This was a big one.

00:19:50.643 --> 00:19:51.819
We have other data and we're hoping to get

00:19:51.819 --> 00:19:54.094
a lot more data this year.

00:19:54.094 --> 00:19:55.586
Once again, not a rigorous
study, so not something

00:19:55.586 --> 00:19:57.453
that we can publish in
a scientific journal,

00:19:57.453 --> 00:19:59.454
but that, with all of
the anecdotal evidence,

00:19:59.454 --> 00:20:01.584
made Los Altos feel pretty good

00:20:01.584 --> 00:20:02.787
and made us feel pretty good.

00:20:02.787 --> 00:20:05.723
We don't consider this a done deal.

00:20:05.723 --> 00:20:07.885
We consider ourselves, we're just in

00:20:07.885 --> 00:20:09.150
the first inning and we have to constantly

00:20:09.150 --> 00:20:10.390
improve this thing so that we can get

00:20:10.390 --> 00:20:11.720
even better results next year,

00:20:11.720 --> 00:20:13.033
and then the year after that.

00:20:13.033 --> 00:20:14.333
Question number 9:

00:20:14.333 --> 00:20:17.255
Do you believe children
should have the opportunity

00:20:17.255 --> 00:20:18.847
to use other new technologies in school,

00:20:18.847 --> 00:20:21.722
such as mobile phones,
iPods, and podcasts?

00:20:21.722 --> 00:20:23.163
I think it's like everything.

00:20:23.163 --> 00:20:27.516
If it's used in a proper
context, yes, if it's helpful.

00:20:27.516 --> 00:20:28.996
If it's not helpful, maybe no.

00:20:28.996 --> 00:20:31.331
We should have an open mind about

00:20:31.331 --> 00:20:33.059
what helpful is or what it isn't

00:20:33.059 --> 00:20:36.410
and just try things out
and adjust accordingly.

00:20:36.410 --> 00:20:37.849
Question 10:

00:20:37.849 --> 00:20:39.745
Are films the new books?

00:20:39.745 --> 00:20:42.789
Do you think that a
culture focused on images

00:20:42.789 --> 00:20:46.678
has contributed to the
notion that books are boring?

00:20:46.678 --> 00:20:49.356
Films, on some level, they are,

00:20:49.356 --> 00:20:51.531
even before Khan Academy shows up,

00:20:51.531 --> 00:20:55.193
films have always been a form of book.

00:20:55.193 --> 00:20:57.492
People still like to read the
book and then watch the film.

00:20:57.492 --> 00:21:00.194
The books give you more
depth, give you more nuance,

00:21:00.194 --> 00:21:01.722
but the films are still fun.

00:21:01.722 --> 00:21:04.190
I don't think it's a
culture focused on images

00:21:04.190 --> 00:21:06.662
that has contributed to the
notion that books are boring.

00:21:06.662 --> 00:21:09.324
I think there are books that
are amazing and fascinating,

00:21:09.324 --> 00:21:11.527
and some of my best experiences in life

00:21:11.527 --> 00:21:13.446
are from reading some
of those amazing books,

00:21:13.446 --> 00:21:15.387
but there are books that are boring.

00:21:15.387 --> 00:21:18.720
It doesn't hurt if we can find a medium

00:21:18.720 --> 00:21:19.925
that is less boring.

00:21:19.925 --> 00:21:22.438
I think it really depends
from case to case.

00:21:22.438 --> 00:21:23.848
And I don't think it's
just this generation.

00:21:23.848 --> 00:21:25.228
I think if you'd taken any generation

00:21:25.228 --> 00:21:27.063
and if you'd given them
something that's less boring

00:21:27.063 --> 00:21:29.402
or a better way or a more intuitive way

00:21:29.402 --> 00:21:31.339
or a more approachable way
to understand something,

00:21:31.339 --> 00:21:35.339
they would have found
it equally compelling.


Cervical spine protection in airway management (not a substitute for formal training)

WEBVTT
Kind: captions
Language: en

00:00:01.154 --> 00:00:02.820
DR. MAHADEVAN: Hi,
this is Dr. Mahadevan

00:00:02.820 --> 00:00:04.990
of Stanford University
School of Medicine.

00:00:04.990 --> 00:00:06.657
I'm here with my good friend--

00:00:06.657 --> 00:00:07.240
SAL KHAN: Sal.

00:00:07.240 --> 00:00:09.290
DR. MAHADEVAN: --Sal Khan.

00:00:09.290 --> 00:00:11.570
And we're following up to
our earlier discussions

00:00:11.570 --> 00:00:15.014
about cervical spine
injuries, or neck injuries.

00:00:15.014 --> 00:00:16.430
And we're going
to talk about some

00:00:16.430 --> 00:00:20.522
of things you might do to
manage a patient who might have

00:00:20.522 --> 00:00:21.980
a cervical spine
injury in the case

00:00:21.980 --> 00:00:23.685
that you had to do
something invasive,

00:00:23.685 --> 00:00:25.134
like manage their airway.

00:00:25.134 --> 00:00:25.800
SAL KHAN: Right.

00:00:25.800 --> 00:00:26.565
When you say manage
their airway,

00:00:26.565 --> 00:00:27.885
there might be something
stuck in their airway,

00:00:27.885 --> 00:00:29.047
or blocking their airway.

00:00:29.047 --> 00:00:30.880
DR. MAHADEVAN: Usually
the tongue falls back

00:00:30.880 --> 00:00:31.500
and blocks the airway.

00:00:31.500 --> 00:00:32.110
But you're right.

00:00:32.110 --> 00:00:34.500
If your airways blocked, you
can't get air to your lungs.

00:00:34.500 --> 00:00:36.250
And if you can't get air
to your lungs, you die.

00:00:36.250 --> 00:00:36.470
SAL KHAN: Right.

00:00:36.470 --> 00:00:38.270
And when you said, usually
your tongue falls back,

00:00:38.270 --> 00:00:40.540
that's normal-- wait, what
are you talking about?

00:00:40.540 --> 00:00:42.180
DR. MAHADEVAN: When
you're unconscious,

00:00:42.180 --> 00:00:45.220
the musculature, or the muscles
that control your tongue,

00:00:45.220 --> 00:00:46.470
relax.

00:00:46.470 --> 00:00:50.630
Because you're unconscious,
your tongue falls back exactly.

00:00:50.630 --> 00:00:53.030
And it falls back into
your pharynx, which

00:00:53.030 --> 00:00:54.900
is a posterior part
of your throat, there,

00:00:54.900 --> 00:00:57.750
and that blocks the air
from either going either

00:00:57.750 --> 00:00:59.970
through your mouth or your
nose into your trachea,

00:00:59.970 --> 00:01:00.770
and then into your lungs.

00:01:00.770 --> 00:01:01.250
SAL KHAN: Really?

00:01:01.250 --> 00:01:02.710
So if someone's
just unconscious,

00:01:02.710 --> 00:01:05.582
and they fall back
like that, that

00:01:05.582 --> 00:01:07.040
might cause them
to stop breathing?

00:01:07.040 --> 00:01:09.040
DR. MAHADEVAN: That would
obstruct their ability

00:01:09.040 --> 00:01:11.331
to breathe, and so even if
they were trying to breathe,

00:01:11.331 --> 00:01:14.110
they wouldn't be able to move
as much air into their lungs.

00:01:14.110 --> 00:01:14.960
SAL KHAN: OK.

00:01:14.960 --> 00:01:16.530
So it could be
literally something

00:01:16.530 --> 00:01:17.920
as simple as moving the
tongue out of the way.

00:01:17.920 --> 00:01:18.878
DR. MAHADEVAN: Exactly.

00:01:18.878 --> 00:01:22.100
And that's really what these
first two diagrams show.

00:01:22.100 --> 00:01:24.120
The one with the
young boy, there,

00:01:24.120 --> 00:01:28.107
is showing a technique called
the head tilt-chin lift.

00:01:28.107 --> 00:01:28.940
SAL KHAN: Head tilt.

00:01:28.940 --> 00:01:32.980
OK, so he's laying down,
they're pushing on his-- OK,

00:01:32.980 --> 00:01:35.510
they're pushing on that hand,
down on the top of his head,

00:01:35.510 --> 00:01:36.732
and then lifting up there.

00:01:36.732 --> 00:01:37.690
DR. MAHADEVAN: Exactly.

00:01:37.690 --> 00:01:40.300
And in doing so, in
sort of tilting the head

00:01:40.300 --> 00:01:42.630
and pulling the chin up,
what you're effectively doing

00:01:42.630 --> 00:01:45.120
is pulling that
tongue out of the way,

00:01:45.120 --> 00:01:47.900
and opening the airway so
air can get into your lungs.

00:01:47.900 --> 00:01:48.620
SAL KHAN: I see.

00:01:48.620 --> 00:01:50.410
And this is a little
off topic, but where

00:01:50.410 --> 00:01:51.730
did you get these pictures?

00:01:51.730 --> 00:01:52.650
DR. MAHADEVAN:
These are actually

00:01:52.650 --> 00:01:53.665
pictures of my children.

00:01:53.665 --> 00:01:55.210
SAL KHAN: Yeah, I
thought he was joking,

00:01:55.210 --> 00:01:56.550
because they're
clearly drawings.

00:01:56.550 --> 00:01:58.520
I thought he lived in some
type of animated reality.

00:01:58.520 --> 00:01:59.730
But no, apparently
they are your children.

00:01:59.730 --> 00:02:01.410
DR. MAHADEVAN: That's my son,
[? Auditya, ?] on the left,

00:02:01.410 --> 00:02:02.740
and my daughter,
[? Lavinya, ?] on the right.

00:02:02.740 --> 00:02:04.950
SAL KHAN: OK, so someone
traced them afterwards.

00:02:04.950 --> 00:02:06.105
They aren't--

00:02:06.105 --> 00:02:08.585
DR. MAHADEVAN: Absolutely,
a very excellent

00:02:08.585 --> 00:02:12.200
medical illustrator
changed them from pictures

00:02:12.200 --> 00:02:13.250
into illustrations.

00:02:13.250 --> 00:02:14.083
SAL KHAN: Very cool.

00:02:14.083 --> 00:02:15.370
So sorry, that was off topic.

00:02:15.370 --> 00:02:17.286
DR. MAHADEVAN: And so
the head tilt-chin lift.

00:02:17.286 --> 00:02:21.290
But as we talked about earlier,
if you had a spine injury,

00:02:21.290 --> 00:02:24.400
moving the neck, or
tilting the head,

00:02:24.400 --> 00:02:26.360
could potentially
cause an injury.

00:02:26.360 --> 00:02:29.250
And so in trauma
victims, we tend

00:02:29.250 --> 00:02:31.570
to avoid using this
particular technique.

00:02:31.570 --> 00:02:33.540
And we use the one
there on the right.

00:02:33.540 --> 00:02:34.590
SAL KHAN: I see, I see.

00:02:34.590 --> 00:02:36.642
Because something
might have happened

00:02:36.642 --> 00:02:37.850
to their spine or their neck.

00:02:37.850 --> 00:02:38.940
DR. MAHADEVAN: And the
last thing you want to do

00:02:38.940 --> 00:02:41.320
is turn their neck, or
flex or extend their neck.

00:02:41.320 --> 00:02:41.610
SAL KHAN: I see.

00:02:41.610 --> 00:02:43.170
Right, because this is going
to put a little pressure

00:02:43.170 --> 00:02:44.792
on the neck around that area.

00:02:44.792 --> 00:02:45.750
DR. MAHADEVAN: Exactly.

00:02:45.750 --> 00:02:46.290
Exactly.

00:02:46.290 --> 00:02:48.357
And the bones can move,
and if the bones move,

00:02:48.357 --> 00:02:49.690
they can injure the spinal cord.

00:02:49.690 --> 00:02:53.309
SAL KHAN: This is, whoever this
person who's hands these are--

00:02:53.309 --> 00:02:54.600
DR. MAHADEVAN: My wife's hands.

00:02:54.600 --> 00:02:55.866
SAL KHAN: Oh, these
are your wife's hands?

00:02:55.866 --> 00:02:56.450
Really?

00:02:56.450 --> 00:02:58.480
It's a family affair.

00:02:58.480 --> 00:03:00.239
And so what is it
she doing exactly?

00:03:00.239 --> 00:03:02.030
DR. MAHADEVAN: She's
doing a maneuver which

00:03:02.030 --> 00:03:04.113
we would use in someone
who potentially could have

00:03:04.113 --> 00:03:06.080
an injury to the neck,
called the jaw thrust.

00:03:06.080 --> 00:03:08.190
And essentially
what she's doing is,

00:03:08.190 --> 00:03:12.680
she's grasping the angle of the
mandible, exactly right there,

00:03:12.680 --> 00:03:14.990
kind of like a little 90
degree angle that we have,

00:03:14.990 --> 00:03:17.790
and pulling that
mandible forward.

00:03:17.790 --> 00:03:19.860
And in doing that,
what she's doing is,

00:03:19.860 --> 00:03:22.880
she's doing the same thing
as the head tilt-chin lift,

00:03:22.880 --> 00:03:25.350
just she's not flexing the
neck or extending the neck.

00:03:25.350 --> 00:03:27.974
SAL KHAN: So you're just kind of
just moving the jaw as opposed

00:03:27.974 --> 00:03:28.790
to everything else.

00:03:28.790 --> 00:03:29.720
DR. MAHADEVAN: And
in moving the jaw,

00:03:29.720 --> 00:03:31.178
you're pulling that
tongue forward,

00:03:31.178 --> 00:03:32.352
and opening the airway.

00:03:32.352 --> 00:03:34.310
SAL KHAN: I see, because
the tongue's in there.

00:03:34.310 --> 00:03:35.030
OK.

00:03:35.030 --> 00:03:36.130
That makes sense.

00:03:36.130 --> 00:03:37.921
DR. MAHADEVAN: And so
this is the technique

00:03:37.921 --> 00:03:39.890
that we use for trauma victims.

00:03:39.890 --> 00:03:41.830
And the reason that
this is important

00:03:41.830 --> 00:03:46.460
is really shown in the x-rays.

00:03:46.460 --> 00:03:48.865
And what you see
is, the same person.

00:03:48.865 --> 00:03:51.850
And in the first
x-ray, you can see,

00:03:51.850 --> 00:03:55.530
as we talked about earlier,
their spine is well aligned.

00:03:55.530 --> 00:03:58.140
So if you were to
check their alignment,

00:03:58.140 --> 00:03:59.470
anterior vertebral body line--

00:03:59.470 --> 00:04:00.360
SAL KHAN: Yeah, I'm an
expert at this, now.

00:04:00.360 --> 00:04:02.318
DR. MAHADEVAN: --posterior
vertebral body line,

00:04:02.318 --> 00:04:05.850
spinolaminar line, and
spinous process line

00:04:05.850 --> 00:04:08.370
all look fine in this
particular circumstance.

00:04:08.370 --> 00:04:13.590
But what you can see, is
if you remove the lines,

00:04:13.590 --> 00:04:16.616
you can see that there
is a small fracture--

00:04:16.616 --> 00:04:17.490
SAL KHAN: Right here.

00:04:17.490 --> 00:04:18.698
DR. MAHADEVAN: --right there.

00:04:18.698 --> 00:04:19.850
Exactly.

00:04:19.850 --> 00:04:21.850
And right in front
of that fracture,

00:04:21.850 --> 00:04:24.160
there's a bunch of swelling.

00:04:24.160 --> 00:04:27.210
All that stuff right there
is your soft tissues,

00:04:27.210 --> 00:04:28.710
and so they're swollen.

00:04:28.710 --> 00:04:33.770
And what you can't see is
that your whole cervical spine

00:04:33.770 --> 00:04:35.650
is held together by ligaments.

00:04:35.650 --> 00:04:38.730
And sometimes they can
be torn, and you may not

00:04:38.730 --> 00:04:40.444
be able to see
them on the x-ray.

00:04:40.444 --> 00:04:41.110
SAL KHAN: I see.

00:04:41.110 --> 00:04:43.230
How did you know there
was swelling here?

00:04:43.230 --> 00:04:45.155
DR. MAHADEVAN: If you
look at the x-ray,

00:04:45.155 --> 00:04:49.320
you can see that the distance
between the front of the spine,

00:04:49.320 --> 00:04:51.399
and the front of the
soft tissues, is widened.

00:04:51.399 --> 00:04:53.190
SAL KHAN: Than what
you would normally see.

00:04:53.190 --> 00:04:53.610
DR. MAHADEVAN: Exactly.

00:04:53.610 --> 00:04:53.900
SAL KHAN: I see

00:04:53.900 --> 00:04:54.858
DR. MAHADEVAN: Exactly.

00:04:54.858 --> 00:04:56.960
It's usually very
small, very narrow

00:04:56.960 --> 00:04:58.565
in that part of
the cervical spine.

00:04:58.565 --> 00:04:59.231
SAL KHAN: I see.

00:04:59.231 --> 00:05:00.210
It makes sense.

00:05:00.210 --> 00:05:01.750
DR. MAHADEVAN: And
what you realize

00:05:01.750 --> 00:05:05.770
is, if a person were to come
and try to open the airway,

00:05:05.770 --> 00:05:08.632
what happens on the next
radiograph could occur.

00:05:08.632 --> 00:05:09.340
So if I were to--

00:05:09.340 --> 00:05:10.890
SAL KHAN: So if they used this
technique right over here.

00:05:10.890 --> 00:05:13.431
DR. MAHADEVAN: Exactly if they
were to use the head tilt-chin

00:05:13.431 --> 00:05:15.200
lift, and were to
tilt that head back--

00:05:15.200 --> 00:05:16.890
SAL KHAN: Oh, yeah, put
that pressure right there.

00:05:16.890 --> 00:05:17.848
DR. MAHADEVAN: Exactly.

00:05:17.848 --> 00:05:20.110
What could happen,
the next x-ray shows--

00:05:20.110 --> 00:05:23.099
SAL KHAN: They push the--
I wanted to use magenta,

00:05:23.099 --> 00:05:23.890
It's easier to see.

00:05:23.890 --> 00:05:25.140
So they push that back--

00:05:25.140 --> 00:05:25.390
DR. MAHADEVAN: Exactly.

00:05:25.390 --> 00:05:27.010
SAL KHAN: And then
[? wow. ?] OK.

00:05:27.010 --> 00:05:29.960
DR. MAHADEVAN: And now if you
were to draw your lines again,

00:05:29.960 --> 00:05:32.905
specifically, the anterior
you might get away with--

00:05:32.905 --> 00:05:34.780
SAL KHAN: Yeah, but
this one right--

00:05:34.780 --> 00:05:35.613
[INTERPOSING VOICES]

00:05:35.613 --> 00:05:38.510
DR. MAHADEVAN: Definitley the
posterior line is abnormal.

00:05:38.510 --> 00:05:41.470
And again, the key fact
here is that, right

00:05:41.470 --> 00:05:44.040
behind that line that you
drew is your spinal cord.

00:05:44.040 --> 00:05:46.880
SAL KHAN: Yes,
which is important.

00:05:46.880 --> 00:05:47.890
Right.

00:05:47.890 --> 00:05:50.990
DR. MAHADEVAN: And so one of the
tenets of Emergency Medicine,

00:05:50.990 --> 00:05:53.150
and medicine in
general, is do no harm.

00:05:53.150 --> 00:05:56.480
And here, in an attempt to
open the air way, by this head

00:05:56.480 --> 00:05:58.795
tilt-chin lift
maneuver, we potentially

00:05:58.795 --> 00:06:00.107
could do harm to the patient.

00:06:00.107 --> 00:06:00.690
SAL KHAN: Yes.

00:06:00.690 --> 00:06:01.490
Wow, wow.

00:06:01.490 --> 00:06:02.240
Do no harm.

00:06:02.240 --> 00:06:05.400
It's a good first rule of thumb.

00:06:05.400 --> 00:06:07.400
Right, right.

00:06:07.400 --> 00:06:09.400
DR. MAHADEVAN: The next
step that we would take,

00:06:09.400 --> 00:06:11.760
if just simply
opening the airway

00:06:11.760 --> 00:06:14.400
wasn't adequate to get
someone breathing again,

00:06:14.400 --> 00:06:17.950
potentially would be to actually
intubate them, or insert

00:06:17.950 --> 00:06:22.210
a plastic breathing
tube into their trachea,

00:06:22.210 --> 00:06:24.090
and allow them to breathe.

00:06:24.090 --> 00:06:26.500
What you can see there
is the act of intubation.

00:06:26.500 --> 00:06:28.030
SAL KHAN: So yeah, I've heard
this word intubate a lot.

00:06:28.030 --> 00:06:29.530
My wife is a
physician, and I always

00:06:29.530 --> 00:06:31.140
hear-- so this is
literally you're

00:06:31.140 --> 00:06:33.397
inserting a tube
to clear things?

00:06:33.397 --> 00:06:34.980
DR. MAHADEVAN: You're
inserting a tube

00:06:34.980 --> 00:06:39.680
to create a passageway from
the oxygen-rich atmosphere,

00:06:39.680 --> 00:06:41.530
and directly into your lungs.

00:06:41.530 --> 00:06:44.520
And again, if your
tongue has fallen back,

00:06:44.520 --> 00:06:47.760
and you can't keep it out
of the way, or you vomited

00:06:47.760 --> 00:06:49.710
and you're
unconscious, this would

00:06:49.710 --> 00:06:50.740
be something that
would help you breathe.

00:06:50.740 --> 00:06:52.240
SAL KHAN: How far
does this tube go?

00:06:52.240 --> 00:06:54.180
DR. MAHADEVAN: It starts
right at your mouth,

00:06:54.180 --> 00:06:55.850
and it goes all the way down--

00:06:55.850 --> 00:06:57.160
SAL KHAN: It's a flexible
tube, I'm assuming.

00:06:57.160 --> 00:06:58.659
DR. MAHADEVAN: It's
a flexible tube,

00:06:58.659 --> 00:07:03.570
and it would go right in between
this cartilage right here.

00:07:03.570 --> 00:07:06.885
So it would kind of go
right there, exactly.

00:07:06.885 --> 00:07:10.410
Right through the larynx,
and right there where

00:07:10.410 --> 00:07:13.030
you've got the pointer, there,
is where your vocal cords are.

00:07:13.030 --> 00:07:16.140
And it would go just
beyond the vocal cords,

00:07:16.140 --> 00:07:17.420
right into your trachea.

00:07:17.420 --> 00:07:18.200
SAL KHAN: I see.

00:07:18.200 --> 00:07:19.050
DR. MAHADEVAN: Exactly, exactly.

00:07:19.050 --> 00:07:20.508
SAL KHAN: And that's
because that's

00:07:20.508 --> 00:07:22.610
where you normally have
something blocking.

00:07:22.610 --> 00:07:24.040
DR. MAHADEVAN: That is
the connection between

00:07:24.040 --> 00:07:25.220
the oxygen-rich environment--

00:07:25.220 --> 00:07:25.580
SAL KHAN: Oh, yeah.

00:07:25.580 --> 00:07:26.750
After that, then
the oxygen can get

00:07:26.750 --> 00:07:28.030
to you, at least some
part of your lungs.

00:07:28.030 --> 00:07:29.571
DR. MAHADEVAN: You've
got a tube now.

00:07:29.571 --> 00:07:32.519
You've got an airway, and
you can give, deliver oxygen

00:07:32.519 --> 00:07:33.810
to a patient through that tube.

00:07:33.810 --> 00:07:34.470
SAL KHAN: I see.

00:07:34.470 --> 00:07:34.770
I see.

00:07:34.770 --> 00:07:35.978
And what are they doing here?

00:07:35.978 --> 00:07:36.960
What are they pinching?

00:07:36.960 --> 00:07:39.050
DR. MAHADEVAN: In this
particular diagram,

00:07:39.050 --> 00:07:40.900
what they're doing
is a couple things.

00:07:40.900 --> 00:07:42.680
There's actually
three people there.

00:07:42.680 --> 00:07:45.260
One person who looks
like they're pinching

00:07:45.260 --> 00:07:47.430
is actually putting
pressure on your cartilage,

00:07:47.430 --> 00:07:49.440
your cricoid cartilage.

00:07:49.440 --> 00:07:52.975
And they're doing that
to push back and occlude

00:07:52.975 --> 00:07:54.077
your esophagus.

00:07:54.077 --> 00:07:55.410
SAL KHAN: Occlude the esophagus.

00:07:55.410 --> 00:07:56.670
What is occlude?

00:07:56.670 --> 00:07:58.950
DR. MAHADEVAN: They want
to close off the esophagus

00:07:58.950 --> 00:08:01.460
because the esophagus
connects to the stomach.

00:08:01.460 --> 00:08:03.827
The stomach is full of
whatever you had to eat.

00:08:03.827 --> 00:08:04.660
SAL KHAN: Oh, I see.

00:08:04.660 --> 00:08:07.140
So you might be continuing
to-- fluid could be coming out

00:08:07.140 --> 00:08:08.651
and all of that.

00:08:08.651 --> 00:08:09.150
I see.

00:08:09.150 --> 00:08:11.502
So there could be stuff
coming out from the stomach.

00:08:11.502 --> 00:08:12.960
DR. MAHADEVAN:
Right and that tube.

00:08:12.960 --> 00:08:18.164
The esophagus runs right back
here, and it could come up.

00:08:18.164 --> 00:08:18.830
SAL KHAN: Sorry.

00:08:18.830 --> 00:08:20.496
Shows how much I know
about [INAUDIBLE].

00:08:23.250 --> 00:08:24.465
DR. MAHADEVAN: Exactly.

00:08:24.465 --> 00:08:26.710
Running right behind
your airway, right there,

00:08:26.710 --> 00:08:29.700
and by pushing back, you
collapse the esophagus

00:08:29.700 --> 00:08:32.836
and prevent any of what we
call passive regurgitation or--

00:08:32.836 --> 00:08:33.502
SAL KHAN: I see.

00:08:33.502 --> 00:08:36.320
So they're pushing this--
and let me do this in another

00:08:36.320 --> 00:08:38.470
color-- they're
actually pushing back,

00:08:38.470 --> 00:08:41.092
and the esophagus is likely
to get closed, then--

00:08:41.092 --> 00:08:42.050
DR. MAHADEVAN: Exactly.

00:08:42.050 --> 00:08:43.140
SAL KHAN: So something
can't come from the stomach.

00:08:43.140 --> 00:08:45.310
That doesn't close-- the
trachea's more rigid?

00:08:45.310 --> 00:08:47.309
DR. MAHADEVAN: The trachea
is a rigid structure.

00:08:47.309 --> 00:08:49.844
And this is actually, the
first ring of the trachea

00:08:49.844 --> 00:08:51.260
is a cricoid
cartilage, and that's

00:08:51.260 --> 00:08:52.190
what they're pushing
on right there.

00:08:52.190 --> 00:08:52.550
SAL KHAN: I see.

00:08:52.550 --> 00:08:54.260
So this is rigid there,
so when you push,

00:08:54.260 --> 00:08:56.480
it closes the esophagus,
trachea can still stay open.

00:08:56.480 --> 00:08:56.850
DR. MAHADEVAN: Exactly.

00:08:56.850 --> 00:08:57.220
SAL KHAN: That makes sense.

00:08:57.220 --> 00:08:58.280
DR. MAHADEVAN: Exactly.

00:08:58.280 --> 00:08:59.280
So there's three people.

00:08:59.280 --> 00:09:01.930
One person that we talked about
is giving cricoid pressure,

00:09:01.930 --> 00:09:05.450
and that would be that gentleman
right there, or a young lady.

00:09:05.450 --> 00:09:08.740
The second person is
actually holding the head,

00:09:08.740 --> 00:09:10.027
as you can see.

00:09:10.027 --> 00:09:11.610
And the reason that
they're doing that

00:09:11.610 --> 00:09:13.860
is for what we showed earlier.

00:09:13.860 --> 00:09:16.490
They don't want that
head to extend or flex.

00:09:16.490 --> 00:09:19.680
So they're actually holding the
person in the neutral position

00:09:19.680 --> 00:09:22.220
to prevent those bones,
potentially, from moving.

00:09:22.220 --> 00:09:22.935
SAL KHAN: Right,
because they're going

00:09:22.935 --> 00:09:24.495
to be jiggling
this thing through,

00:09:24.495 --> 00:09:26.562
and if there wasn't
someone holding it,

00:09:26.562 --> 00:09:27.770
it could do that same damage.

00:09:27.770 --> 00:09:28.070
DR. MAHADEVAN: Absolutely.

00:09:28.070 --> 00:09:28.370
[INTERPOSING VOICES]

00:09:28.370 --> 00:09:30.990
DR. MAHADEVAN: And when you're
that guy at the top who's

00:09:30.990 --> 00:09:33.394
trying to see the vocal
cords, and pass the tube,

00:09:33.394 --> 00:09:34.810
you don't care
about anything else

00:09:34.810 --> 00:09:36.226
except for seeing
the vocal cords.

00:09:36.226 --> 00:09:39.155
So you might inadvertently flex
the neck or extend the neck.

00:09:39.155 --> 00:09:39.825
SAL KHAN: Right,
that makes sense.

00:09:39.825 --> 00:09:40.560
It makes sense.

00:09:40.560 --> 00:09:42.459
Is that also why they
say at an accident,

00:09:42.459 --> 00:09:44.500
no, don't move the person
and that type of thing?

00:09:44.500 --> 00:09:46.030
DR. MAHADEVAN:
That's exactly why.

00:09:46.030 --> 00:09:47.460
Again, do no harm.

00:09:47.460 --> 00:09:50.100
In trying to help the
person by lifting them up,

00:09:50.100 --> 00:09:52.260
or tilting their head,
or flexing their neck,

00:09:52.260 --> 00:09:53.960
you potentially could cause a--

00:09:53.960 --> 00:09:55.810
SAL KHAN: And that's why wait
for the EMTs, or whoever,

00:09:55.810 --> 00:09:56.570
and then they'll--

00:09:56.570 --> 00:09:57.030
DR. MAHADEVAN: Absolutely.

00:09:57.030 --> 00:09:57.290
SAL KHAN: --do it right.

00:09:57.290 --> 00:09:57.500
I see.

00:09:57.500 --> 00:09:59.350
DR. MAHADEVAN: And if you
really had to open their airway,

00:09:59.350 --> 00:10:00.934
you could use the
jaw thrust maneuver.

00:10:00.934 --> 00:10:01.599
SAL KHAN: Right.

00:10:01.599 --> 00:10:03.040
Just pull their jaw forward.

00:10:03.040 --> 00:10:03.320
DR. MAHADEVAN: Exactly.

00:10:03.320 --> 00:10:03.930
SAL KHAN: And hold on to the--

00:10:03.930 --> 00:10:04.888
DR. MAHADEVAN: Exactly.

00:10:06.471 --> 00:10:08.220
SAL KHAN: We touched
on right before this,

00:10:08.220 --> 00:10:09.595
there's other ways
of doing this?

00:10:09.595 --> 00:10:12.590
Or there's other methods
that people talk about?

00:10:12.590 --> 00:10:14.090
DR. MAHADEVAN: This
cricoid pressure

00:10:14.090 --> 00:10:17.350
is quite controversial,
because one of the things

00:10:17.350 --> 00:10:20.090
is it's supposed to help
you with this procedure,

00:10:20.090 --> 00:10:22.630
and some people feel that it
may not be proven to help you.

00:10:22.630 --> 00:10:24.590
Or it potentially
can cause injury.

00:10:24.590 --> 00:10:26.530
But for those of
us that are older,

00:10:26.530 --> 00:10:29.160
have used this technique for a
long time, still stand by it.

00:10:29.160 --> 00:10:31.100
SAL KHAN: OK, this is what y'all
teach it at the med school.

00:10:31.100 --> 00:10:31.600
DR. MAHADEVAN: Exactly.

00:10:31.600 --> 00:10:31.850
SAL KHAN: OK.

00:10:31.850 --> 00:10:32.680
DR. MAHADEVAN: Exactly.

00:10:32.680 --> 00:10:33.763
SAL KHAN: Well, thank you.

00:10:33.763 --> 00:10:34.970
This is very, very useful.

00:10:34.970 --> 00:10:36.650
DR. MAHADEVAN: You bet.


Assessing alignment of the lateral cervical spine (neck) X-ray

WEBVTT
Kind: captions
Language: en

00:00:00.000 --> 00:00:01.634
SAL KHAN: This is
Sal here again.

00:00:01.634 --> 00:00:03.800
And I'm still here with my
good friend Dr. Mahadevan

00:00:03.800 --> 00:00:05.390
from Stanford University.

00:00:05.390 --> 00:00:09.670
And in the last video, we had
looked at adequacy of x-rays,

00:00:09.670 --> 00:00:11.822
for the neck, which is,
is the x-ray good enough.

00:00:11.822 --> 00:00:13.530
But now let's assume
we have good x-rays.

00:00:13.530 --> 00:00:14.530
Now, what do we look at?

00:00:14.530 --> 00:00:18.010
DR. MAHADEVAN: The next step
is to look at the alignment.

00:00:18.010 --> 00:00:22.600
So we talk about the ABCs of
reading a cervical spine film.

00:00:22.600 --> 00:00:25.410
And A starts with adequacy,
that we went over.

00:00:25.410 --> 00:00:28.450
And the second part
of A is alignment.

00:00:28.450 --> 00:00:29.120
SAL KHAN: OK.

00:00:29.120 --> 00:00:31.769
So we're still in A.
So now it's alignment.

00:00:31.769 --> 00:00:34.143
I was expecting something with
a B. All right, alignment.

00:00:36.930 --> 00:00:37.454
All right.

00:00:37.454 --> 00:00:39.245
So this looks like this
is about alignment.

00:00:39.245 --> 00:00:40.870
DR. MAHADEVAN: This
is about alignment.

00:00:40.870 --> 00:00:43.120
And there's four
lines that we look at.

00:00:43.120 --> 00:00:46.560
The first is the anterior
vertebral body line.

00:00:46.560 --> 00:00:48.330
SAL KHAN: OK, AVBL,
right over there.

00:00:48.330 --> 00:00:48.940
DR. MAHADEVAN: Exactly.

00:00:48.940 --> 00:00:50.440
And basically, what
you're doing is,

00:00:50.440 --> 00:00:54.180
you're trying to draw a smooth
line that connects the anterior

00:00:54.180 --> 00:00:57.200
aspect, the front of all
the vertebral bodies.

00:00:57.200 --> 00:00:58.750
It should be nice and smooth.

00:00:58.750 --> 00:01:00.270
It's usually curved.

00:01:00.270 --> 00:01:03.230
And all the points should
sort of fit on that line.

00:01:03.230 --> 00:01:05.087
Nothing should be
off of that line.

00:01:05.087 --> 00:01:07.170
That would suggest that
there was a problem there.

00:01:07.170 --> 00:01:07.957
SAL KHAN: I see.

00:01:07.957 --> 00:01:09.790
And anterior, as you
just said, means front.

00:01:09.790 --> 00:01:10.360
DR. MAHADEVAN: Exactly.

00:01:10.360 --> 00:01:11.410
SAL KHAN: Right, OK.

00:01:11.410 --> 00:01:13.860
DR. MAHADEVAN: The
next line is going

00:01:13.860 --> 00:01:15.709
to the back of the
vertebral body.

00:01:15.709 --> 00:01:17.125
It's the posterior
vertebral body.

00:01:17.125 --> 00:01:19.940
SAL KHAN: So not the back
of the entire vertebrae,

00:01:19.940 --> 00:01:22.682
the vertebral body, which is
this boxy part right in front.

00:01:22.682 --> 00:01:23.640
DR. MAHADEVAN: Exactly.

00:01:23.640 --> 00:01:28.100
And so same thing,
connecting a line up and down

00:01:28.100 --> 00:01:30.460
should be nice and smooth,
as you've drawn it.

00:01:30.460 --> 00:01:32.940
And nothing should
fall off that line.

00:01:32.940 --> 00:01:35.730
No piece of that vertebral
body should fall off

00:01:35.730 --> 00:01:36.730
of the line you've draw.

00:01:36.730 --> 00:01:37.880
SAL KHAN: All
right, sounds good.

00:01:37.880 --> 00:01:38.379
And then?

00:01:38.379 --> 00:01:42.540
DR. MAHADEVAN: The next is, we
connect all the spinolaminar

00:01:42.540 --> 00:01:43.200
junctions.

00:01:43.200 --> 00:01:45.570
So this is the
spinolaminar line.

00:01:45.570 --> 00:01:49.080
And it's where the
lamina connects

00:01:49.080 --> 00:01:50.746
to the spinous process.

00:01:50.746 --> 00:01:52.310
SAL KHAN: Spinous
process, it sounds

00:01:52.310 --> 00:01:54.290
like we could make a
whole video about that.

00:01:54.290 --> 00:01:55.310
DR. MAHADEVAN: Spinous
process, if you

00:01:55.310 --> 00:01:56.810
look at the back
of somebody's neck,

00:01:56.810 --> 00:01:58.502
are those little bumps
that you can see.

00:01:58.502 --> 00:01:59.710
And that's the very back end.

00:01:59.710 --> 00:02:01.440
SAL KHAN: And that's these
triangular things right here.

00:02:01.440 --> 00:02:02.398
DR. MAHADEVAN: Exactly.

00:02:02.398 --> 00:02:03.530
SAL KHAN: OK.

00:02:03.530 --> 00:02:05.369
So you're just
connecting that line.

00:02:05.369 --> 00:02:06.910
Kind of the front
of these triangles,

00:02:06.910 --> 00:02:08.419
the base of these
triangles, so to speak.

00:02:08.419 --> 00:02:09.090
DR. MAHADEVAN: Exactly.

00:02:09.090 --> 00:02:10.360
SAL KHAN: And then the last one?

00:02:10.360 --> 00:02:12.901
DR. MAHADEVAN: And the last line
is the spinous process tips.

00:02:12.901 --> 00:02:14.770
And again, we're just
connecting the top,

00:02:14.770 --> 00:02:17.050
the tip of all these
spinous processes,

00:02:17.050 --> 00:02:19.080
the little bony
projections you can

00:02:19.080 --> 00:02:21.370
see if you look at the
back of somebody's neck.

00:02:21.370 --> 00:02:25.180
And these two should generally
fall in a nice, smooth curve.

00:02:25.180 --> 00:02:27.540
SAL KHAN: And so the general
rule-- if any of these

00:02:27.540 --> 00:02:30.510
aren't aligned the way
that we've drawn here,

00:02:30.510 --> 00:02:31.135
it's a problem.

00:02:31.135 --> 00:02:32.468
DR. MAHADEVAN: Exactly, exactly.

00:02:32.468 --> 00:02:37.080
We call it subluxation or
malalignment or misalignment.

00:02:37.080 --> 00:02:40.499
And these all suggest that
there is a problem there.

00:02:40.499 --> 00:02:42.790
SAL KHAN: Which is a big
deal, because your spinal cord

00:02:42.790 --> 00:02:43.450
is running through there.

00:02:43.450 --> 00:02:44.150
DR. MAHADEVAN: Absolutely.

00:02:44.150 --> 00:02:46.900
If you look between the two,
the green and the blue line,

00:02:46.900 --> 00:02:49.764
that's actually where your
actual spinal cord runs.

00:02:49.764 --> 00:02:50.430
SAL KHAN: Right.

00:02:50.430 --> 00:02:51.139
Right down there.

00:02:51.139 --> 00:02:52.096
DR. MAHADEVAN: Exactly.

00:02:52.096 --> 00:02:52.770
SAL KHAN: I see.

00:02:52.770 --> 00:02:54.610
So you don't want
that to get messed up.

00:02:54.610 --> 00:02:55.110
All right.

00:02:55.110 --> 00:02:57.010
So let's look at a
few of these x-rays

00:02:57.010 --> 00:02:59.240
and see if, one,
anything's wrong.

00:02:59.240 --> 00:03:01.645
Or if there's something,
if we can spot it.

00:03:01.645 --> 00:03:03.020
DR. MAHADEVAN:
Actually, Sal, now

00:03:03.020 --> 00:03:05.120
that you know how to read
cervical spine x-rays.

00:03:05.120 --> 00:03:07.036
I'm going to have you
look at the first x-ray.

00:03:07.036 --> 00:03:08.337
SAL KHAN: OK, let's see.

00:03:08.337 --> 00:03:09.920
I'm going to get
sued for malpractice.

00:03:09.920 --> 00:03:10.910
Let's see.

00:03:10.910 --> 00:03:11.910
All right.

00:03:11.910 --> 00:03:13.712
So this one over here.

00:03:13.712 --> 00:03:15.045
So let me just do the first one.

00:03:15.045 --> 00:03:16.836
Let me just go with
what you told me to do.

00:03:16.836 --> 00:03:20.374
So I'm going to do the anterior
side of this vertebral body.

00:03:20.374 --> 00:03:21.332
DR. MAHADEVAN: Exactly.

00:03:21.332 --> 00:03:23.123
SAL KHAN: Look, I'm
learning the words too,

00:03:23.123 --> 00:03:24.430
talking like a doctor.

00:03:24.430 --> 00:03:26.430
So I'm going to
draw a line here.

00:03:26.430 --> 00:03:28.490
That looks pretty good.

00:03:28.490 --> 00:03:31.260
That looks decent.

00:03:31.260 --> 00:03:32.140
What is it?

00:03:32.140 --> 00:03:33.900
I'm kind of-- let me see.

00:03:33.900 --> 00:03:36.770
This still looks decent.

00:03:36.770 --> 00:03:40.152
And that doesn't look great.

00:03:40.152 --> 00:03:40.860
Would this count?

00:03:40.860 --> 00:03:43.570
I mean, this looks like it
got shifted over a little bit.

00:03:43.570 --> 00:03:44.670
DR. MAHADEVAN: Absolutely.

00:03:44.670 --> 00:03:46.420
SAL KHAN: It's not
a huge shifting.

00:03:46.420 --> 00:03:48.930
But it's enough that it's
not easy to draw a line.

00:03:48.930 --> 00:03:49.820
So I was right?

00:03:49.820 --> 00:03:51.445
DR. MAHADEVAN: You're
absolutely right.

00:03:51.445 --> 00:03:54.020
And in fact, sometimes
it's very subtle.

00:03:54.020 --> 00:03:55.930
And you picked up a
very subtle abnormality.

00:03:55.930 --> 00:03:58.285
But again, even though
it's subtle on the x-ray,

00:03:58.285 --> 00:04:00.080
it could be serious
for the patient.

00:04:00.080 --> 00:04:03.174
So you potentially saved their
spinal cord and their lives,

00:04:03.174 --> 00:04:04.590
by picking up an
injury like this.

00:04:04.590 --> 00:04:05.420
SAL KHAN: OK, good.

00:04:05.420 --> 00:04:07.070
You're making me
feel-- very good.

00:04:07.070 --> 00:04:09.720
So that's-- it's literally
something as subtle as that is

00:04:09.720 --> 00:04:10.720
what you're looking for.

00:04:10.720 --> 00:04:11.180
DR. MAHADEVAN: Exactly.

00:04:11.180 --> 00:04:13.000
Again, it should be
a nice, smooth line

00:04:13.000 --> 00:04:14.300
or a nice, smooth curve.

00:04:14.300 --> 00:04:16.754
And as you can see,
at that junction,

00:04:16.754 --> 00:04:17.670
it's no longer smooth.

00:04:17.670 --> 00:04:18.564
SAL KHAN: And you
don't even have

00:04:18.564 --> 00:04:20.070
to look at the other lines.

00:04:20.070 --> 00:04:22.650
Any one of these that you don't
align, that's enough to say,

00:04:22.650 --> 00:04:23.632
hey, do something else.

00:04:23.632 --> 00:04:24.590
DR. MAHADEVAN: Exactly.

00:04:24.590 --> 00:04:26.340
And that's a great,
important teaching

00:04:26.340 --> 00:04:29.230
point, which is, if you see
any abnormality on a plane film

00:04:29.230 --> 00:04:31.350
on an x-ray like this, you stop.

00:04:31.350 --> 00:04:33.330
And you protect
their cervical spine.

00:04:33.330 --> 00:04:35.110
And then you get a
more important study

00:04:35.110 --> 00:04:37.044
or a better quality
study, like a CT scan.

00:04:37.044 --> 00:04:37.960
SAL KHAN: Fascinating.

00:04:37.960 --> 00:04:39.418
Although if I do
look here, it does

00:04:39.418 --> 00:04:41.030
look like we could
have done the PVBL.

00:04:41.030 --> 00:04:43.497
And it looks like that
also is a little off too.

00:04:43.497 --> 00:04:44.580
DR. MAHADEVAN: Absolutely.

00:04:44.580 --> 00:04:47.140
SAL KHAN: That one and-- OK,
well, let's get a few more.

00:04:47.140 --> 00:04:48.015
DR. MAHADEVAN: Great.

00:04:48.015 --> 00:04:50.990
SAL KHAN: I don't want to focus
too much on my first victory.

00:04:50.990 --> 00:04:52.490
All right.

00:04:52.490 --> 00:04:55.450
So it's clear this person
is facing this way.

00:04:55.450 --> 00:04:57.710
I can see their teeth.

00:04:57.710 --> 00:04:59.790
So let's see what
we can do here.

00:04:59.790 --> 00:05:01.090
Can I give it a shot again?

00:05:01.090 --> 00:05:02.340
DR. MAHADEVAN: Please, please.

00:05:02.340 --> 00:05:07.050
SAL KHAN: So let's-- the
AVBL, it looks pretty good.

00:05:07.050 --> 00:05:10.360
This is-- well,
that looks close.

00:05:10.360 --> 00:05:12.190
DR. MAHADEVAN: It
looks close, I agree.

00:05:12.190 --> 00:05:15.920
And potentially, again,
you've got a very keen eye

00:05:15.920 --> 00:05:17.120
and might have picked it up.

00:05:17.120 --> 00:05:18.200
But most people might--

00:05:18.200 --> 00:05:19.850
SAL KHAN: A gift, you might say.

00:05:19.850 --> 00:05:21.683
DR. MAHADEVAN: --might
have overlooked that.

00:05:21.683 --> 00:05:24.480
SAL KHAN: So let's try
the other lines here.

00:05:27.600 --> 00:05:28.100
OK.

00:05:28.100 --> 00:05:29.830
So this one is more obvious.

00:05:29.830 --> 00:05:31.397
This one is more
obvious that there's

00:05:31.397 --> 00:05:33.230
kind of that disconnection
right over there.

00:05:33.230 --> 00:05:34.188
DR. MAHADEVAN: Exactly.

00:05:34.188 --> 00:05:37.160
And this is the PVBL, or the
posterior vertebral body line.

00:05:37.160 --> 00:05:40.210
You can see clearly,
that line is not smooth.

00:05:40.210 --> 00:05:43.112
It doesn't connect, and
so there is a problem

00:05:43.112 --> 00:05:44.320
right there at that junction.

00:05:44.320 --> 00:05:45.770
SAL KHAN: OK.

00:05:45.770 --> 00:05:48.740
All right, and so now we have
this last one right over here.

00:05:48.740 --> 00:05:50.800
Let me see what I can do.

00:05:50.800 --> 00:05:53.410
Let me see, don't want
to lose my streak.

00:05:53.410 --> 00:05:53.910
All right.

00:05:53.910 --> 00:05:58.677
So interior side-- this actually
looks pretty perfect actually.

00:05:58.677 --> 00:06:00.510
DR. MAHADEVAN: And in
fact, it is a perfect.

00:06:00.510 --> 00:06:02.400
SAL KHAN: OK.

00:06:02.400 --> 00:06:05.780
Let me try the next lines here.

00:06:05.780 --> 00:06:07.650
This is the posterior
vertebral body.

00:06:07.650 --> 00:06:09.608
Let me do that in a color
that's easier to see.

00:06:09.608 --> 00:06:10.690
I already used orange.

00:06:10.690 --> 00:06:12.140
I'll do magenta.

00:06:12.140 --> 00:06:12.640
All right.

00:06:12.640 --> 00:06:17.280
So this is looking OK.

00:06:17.280 --> 00:06:18.770
It looks OK.

00:06:22.860 --> 00:06:24.942
I mean, nothing
obvious on that line.

00:06:24.942 --> 00:06:27.400
DR. MAHADEVAN: I would say,
again, you've got the keen eye.

00:06:27.400 --> 00:06:30.220
But in this particular
case, I'd say, it's fine.

00:06:30.220 --> 00:06:32.270
It's within the normal
range, as we say.

00:06:32.270 --> 00:06:35.640
SAL KHAN: And so let me do
the base of those triangles.

00:06:35.640 --> 00:06:39.784
Let me do-- so this is a
triangle right over here.

00:06:39.784 --> 00:06:42.330
DR. MAHADEVAN: Again, you want
it to be a nice, smooth curve.

00:06:42.330 --> 00:06:44.290
Everything should
fall on that curve.

00:06:44.290 --> 00:06:47.790
SAL KHAN: So this-- I would
have to be a little bit generous

00:06:47.790 --> 00:06:51.870
with my curve to make it
go to these guys down here.

00:06:51.870 --> 00:06:54.090
DR. MAHADEVAN: Exactly.

00:06:54.090 --> 00:06:57.540
And this is the
spinal laminar line.

00:06:57.540 --> 00:06:59.380
This is the third
line of alignment.

00:06:59.380 --> 00:07:02.820
As you can see, to try to
get those to work, you could.

00:07:02.820 --> 00:07:04.680
But they're not smooth
like the other lines.

00:07:04.680 --> 00:07:06.471
And this is, again,
another subtle finding.

00:07:06.471 --> 00:07:10.775
But missing this finding because
the first two lines are normal

00:07:10.775 --> 00:07:12.695
could again be devastating
for the patient.

00:07:12.695 --> 00:07:13.644
SAL KHAN: Right.

00:07:13.644 --> 00:07:15.560
You always want to err
on the side of caution.

00:07:15.560 --> 00:07:18.290
I mean, if anything looks
even a little bit suspicious,

00:07:18.290 --> 00:07:19.296
maybe another x-ray.

00:07:19.296 --> 00:07:21.670
DR. MAHADEVAN: Yeah, another
x-ray, another view, like we

00:07:21.670 --> 00:07:22.560
talked about before.

00:07:22.560 --> 00:07:26.130
Or the definitive study is a CT
scan, or Computed Tomography.

00:07:26.130 --> 00:07:28.044
SAL KHAN: I see, very cool.

00:07:28.044 --> 00:07:28.960
Well, thanks for this.

00:07:28.960 --> 00:07:29.590
This is useful.

00:07:29.590 --> 00:07:31.560
DR. MAHADEVAN: My pleasure.


Adequacy of the lateral cervical spine X-ray

WEBVTT
Kind: captions
Language: en

00:00:00.500 --> 00:00:02.290
SAL KHAN: I'm here
with Dr. Mahadevan,

00:00:02.290 --> 00:00:04.059
who's an ER physician
at Stanford.

00:00:04.059 --> 00:00:05.649
And what are we looking at here?

00:00:05.649 --> 00:00:07.190
DR. MAHADEVAN: Well,
what we're going

00:00:07.190 --> 00:00:09.160
to do is look at
some radiographs

00:00:09.160 --> 00:00:11.450
of the cervical
spine or of your neck

00:00:11.450 --> 00:00:14.215
and try to determine whether
they're adequate or not.

00:00:14.215 --> 00:00:16.554
SAL KHAN: And what does
it mean to be adequate?

00:00:16.554 --> 00:00:18.470
DR. MAHADEVAN: When you
have an adequate view,

00:00:18.470 --> 00:00:20.480
you can see from
the first vertebra

00:00:20.480 --> 00:00:24.000
all way down to the junction of
the seventh cervical vertebra

00:00:24.000 --> 00:00:25.340
and the first thoracic vertebra.

00:00:25.340 --> 00:00:26.024
SAL KHAN: I see.

00:00:26.024 --> 00:00:27.440
And we call it
adequate because it

00:00:27.440 --> 00:00:29.106
means it's adequate
to make a diagnosis.

00:00:29.106 --> 00:00:30.190
DR. MAHADEVAN: Exactly.

00:00:30.190 --> 00:00:32.560
You want to be able to see
the entire cervical spine,

00:00:32.560 --> 00:00:34.810
so you can make sure that
there's not an injury there.

00:00:34.810 --> 00:00:35.954
SAL KHAN: Cool, cool.

00:00:35.954 --> 00:00:37.620
And so what are we
looking at over here?

00:00:37.620 --> 00:00:38.953
What are we directly staring at?

00:00:38.953 --> 00:00:42.690
DR. MAHADEVAN: So what we're
looking at is the lateral,

00:00:42.690 --> 00:00:45.740
which shows essentially
part of the cervical spine,

00:00:45.740 --> 00:00:49.150
shows cervical vertebra
one through five.

00:00:49.150 --> 00:00:49.950
SAL KHAN: I see.

00:00:49.950 --> 00:00:52.370
So just to make myself clear.

00:00:52.370 --> 00:00:54.527
So these are both
lateral x-rays.

00:00:54.527 --> 00:00:55.360
And we say, lateral.

00:00:55.360 --> 00:00:58.560
It is actually from
the side of the person.

00:00:58.560 --> 00:01:00.590
And this shows how
well I know my anatomy.

00:01:00.590 --> 00:01:02.890
This person, on this x-ray,
they're facing this way?

00:01:02.890 --> 00:01:04.519
DR. MAHADEVAN: They're
actually facing the other way.

00:01:04.519 --> 00:01:05.260
SAL KHAN: See, look at that.

00:01:05.260 --> 00:01:06.470
I can see, there's a little jaw.

00:01:06.470 --> 00:01:06.970
OK.

00:01:06.970 --> 00:01:09.720
No, I was just testing you.

00:01:09.720 --> 00:01:10.430
Good job.

00:01:10.430 --> 00:01:10.930
All right.

00:01:10.930 --> 00:01:12.780
So the person is
facing that way.

00:01:12.780 --> 00:01:14.280
This way is the front.

00:01:14.280 --> 00:01:15.790
And you were just
showing-- you were

00:01:15.790 --> 00:01:18.407
kind of counting
the different bones.

00:01:18.407 --> 00:01:19.365
DR. MAHADEVAN: Exactly.

00:01:19.365 --> 00:01:20.920
SAL KHAN: And you were
saying, this is one.

00:01:20.920 --> 00:01:21.810
DR. MAHADEVAN: That's one.

00:01:21.810 --> 00:01:22.280
SAL KHAN: Two.

00:01:22.280 --> 00:01:23.071
DR. MAHADEVAN: Two.

00:01:23.071 --> 00:01:24.914
SAL KHAN: Three,
four, five, and that's

00:01:24.914 --> 00:01:27.330
why you hear people, sometimes,
with back injuries saying,

00:01:27.330 --> 00:01:29.121
I have a problem in--
what do they call it?

00:01:29.121 --> 00:01:30.400
DR. MAHADEVAN: L5 is one.

00:01:30.400 --> 00:01:31.210
SAL KHAN: Right.

00:01:31.210 --> 00:01:32.850
That's what they're
talking about, like that.

00:01:32.850 --> 00:01:33.420
OK, so sorry.

00:01:33.420 --> 00:01:36.820
DR. MAHADEVAN: And actually,
we count even further forward

00:01:36.820 --> 00:01:37.682
from there.

00:01:37.682 --> 00:01:39.890
And we look exactly at those
things that kind of look

00:01:39.890 --> 00:01:41.300
like squares.

00:01:41.300 --> 00:01:44.536
Those are the actual vertebra,
exactly, right there.

00:01:44.536 --> 00:01:45.160
SAL KHAN: This.

00:01:45.160 --> 00:01:46.285
DR. MAHADEVAN: Exactly.

00:01:46.285 --> 00:01:49.100
And although we're interested
in the entire the spine, when

00:01:49.100 --> 00:01:49.600
we count.

00:01:49.600 --> 00:01:50.391
We kind of go down.

00:01:50.391 --> 00:01:53.010
And as you can see, if you
look at the fifth square

00:01:53.010 --> 00:01:56.980
there, below that it's
really hard to see

00:01:56.980 --> 00:01:59.137
the squares of six and seven.

00:01:59.137 --> 00:02:01.220
SAL KHAN: Right, we can't
see anything below that.

00:02:01.220 --> 00:02:02.560
And looks like what is
this person's shoulder

00:02:02.560 --> 00:02:03.310
is blocking it.

00:02:03.310 --> 00:02:04.140
DR. MAHADEVAN: Exactly.

00:02:04.140 --> 00:02:05.931
You can see that that
big white thing there

00:02:05.931 --> 00:02:07.799
is the shoulder that's
gotten in the way.

00:02:07.799 --> 00:02:09.090
And it's making it hard to see.

00:02:09.090 --> 00:02:11.590
SAL KHAN: They shouldn't have
worn those lead shoulder pads.

00:02:11.590 --> 00:02:14.465
DR. MAHADEVAN: [LAUGHING]
And it's making it

00:02:14.465 --> 00:02:16.840
hard to see whether there's
something going on down there

00:02:16.840 --> 00:02:17.260
right now.

00:02:17.260 --> 00:02:19.010
So it's really a
mystery, as you've shown.

00:02:19.010 --> 00:02:21.247
SAL KHAN: So how do
you solve this problem?

00:02:21.247 --> 00:02:23.330
DR. MAHADEVAN: If you look
over at the other film,

00:02:23.330 --> 00:02:25.300
it's what we call
a swimmer's view.

00:02:25.300 --> 00:02:27.440
And what we've asked
the patient to do

00:02:27.440 --> 00:02:31.540
is raise one arm up
and lower the other.

00:02:31.540 --> 00:02:36.000
And in doing so, you kind of
clear that lower cervical spine

00:02:36.000 --> 00:02:38.584
and allow better visualization
of the entire spine.

00:02:38.584 --> 00:02:39.250
SAL KHAN: I see.

00:02:39.250 --> 00:02:41.927
And you're taking it from the
direction of the raised arm,

00:02:41.927 --> 00:02:43.010
on the side of raised arm.

00:02:43.010 --> 00:02:44.350
DR. MAHADEVAN: You
take it from the side.

00:02:44.350 --> 00:02:45.140
And you can see.

00:02:45.140 --> 00:02:47.000
SAL KHAN: This is the
raised arm right over here.

00:02:47.000 --> 00:02:48.916
DR. MAHADEVAN: Exactly,
that's the raised arm.

00:02:48.916 --> 00:02:49.890
SAL KHAN: I see.

00:02:49.890 --> 00:02:52.995
And the other arm on the further
side of the patient is down.

00:02:52.995 --> 00:02:55.620
And that's what allows us to get
to the shoulder in a position,

00:02:55.620 --> 00:02:57.475
so it doesn't block like
it does in this left view.

00:02:57.475 --> 00:02:58.395
DR. MAHADEVAN: Exactly, exactly.

00:02:58.395 --> 00:02:59.160
SAL KHAN: I see.

00:02:59.160 --> 00:03:01.280
And over here, it
is much clearer

00:03:01.280 --> 00:03:04.740
that this person is also
facing in this direction.

00:03:04.740 --> 00:03:05.300
And OK.

00:03:05.300 --> 00:03:06.050
So let me see.

00:03:06.050 --> 00:03:07.230
So we can count.

00:03:07.230 --> 00:03:08.750
This is number
one right up here.

00:03:08.750 --> 00:03:09.900
DR. MAHADEVAN: That's one.

00:03:09.900 --> 00:03:14.424
SAL KHAN: One, two, three,
four, five, six-- yeah,

00:03:14.424 --> 00:03:15.340
we already got to six.

00:03:15.340 --> 00:03:16.844
We didn't see six over here.

00:03:16.844 --> 00:03:17.760
And then we got seven.

00:03:17.760 --> 00:03:18.718
DR. MAHADEVAN: Exactly.

00:03:18.718 --> 00:03:19.279
SAL KHAN: OK.

00:03:19.279 --> 00:03:21.820
And so you would call this is
an adequate view for what we're

00:03:21.820 --> 00:03:24.160
trying-- of the neck, because
now we can look at all the way

00:03:24.160 --> 00:03:24.670
through seven.

00:03:24.670 --> 00:03:25.190
DR. MAHADEVAN: Absolutely.

00:03:25.190 --> 00:03:26.740
We can get all the
way down to seven.

00:03:26.740 --> 00:03:28.921
And ideally, you want to
see the top of one, which

00:03:28.921 --> 00:03:30.670
comes-- actually, in
this counting system,

00:03:30.670 --> 00:03:31.880
we go one through seven.

00:03:31.880 --> 00:03:33.380
And then we start
back at one again,

00:03:33.380 --> 00:03:35.130
because we're starting with
the thoracic vertebrae.

00:03:35.130 --> 00:03:36.282
SAL KHAN: Oh, look at that.

00:03:36.282 --> 00:03:38.740
It's like with those streets,
where they restart numbering.

00:03:38.740 --> 00:03:40.060
And you can't find it.

00:03:40.060 --> 00:03:40.560
All right.

00:03:40.560 --> 00:03:41.632
So it becomes one again.

00:03:41.632 --> 00:03:42.590
DR. MAHADEVAN: Exactly.

00:03:42.590 --> 00:03:44.020
SAL KHAN: Did I
number that right?

00:03:44.020 --> 00:03:44.978
DR. MAHADEVAN: You did.

00:03:44.978 --> 00:03:47.740
And again, we're looking
more to the front.

00:03:47.740 --> 00:03:49.370
You've got your
numbers perfectly

00:03:49.370 --> 00:03:52.100
on every spinous process, the
little bump that you can feel,

00:03:52.100 --> 00:03:54.190
if you press on the
back of your neck.

00:03:54.190 --> 00:03:56.780
But what we're really
interested is the alignment

00:03:56.780 --> 00:03:58.780
of the front of the
vertebral bodies.

00:03:58.780 --> 00:03:59.884
SAL KHAN: So this is one.

00:03:59.884 --> 00:04:03.153
This is two, three,
four, five, six, seven.

00:04:03.153 --> 00:04:05.570
You want to look
at the top of one.

00:04:05.570 --> 00:04:06.935
Where's the top of one?

00:04:06.935 --> 00:04:09.370
DR. MAHADEVAN: If you just
continue down right there.

00:04:09.370 --> 00:04:10.945
And it sometimes is
difficult to see.

00:04:10.945 --> 00:04:13.070
But exactly, you want to
see that there's alignment

00:04:13.070 --> 00:04:14.029
right in front of--

00:04:14.029 --> 00:04:14.570
SAL KHAN: OK.

00:04:14.570 --> 00:04:16.194
I'll assume that
there's something here

00:04:16.194 --> 00:04:17.365
that I can't really see.

00:04:17.365 --> 00:04:18.240
But you're an expert.

00:04:18.240 --> 00:04:20.000
So maybe you see
things that I don't.

00:04:20.000 --> 00:04:20.942
All right.

00:04:20.942 --> 00:04:22.400
OK, so now what do
we do with this?

00:04:22.400 --> 00:04:25.020
DR. MAHADEVAN: Now,
we've shown you

00:04:25.020 --> 00:04:26.510
that you can get
a swimmer's view.

00:04:26.510 --> 00:04:30.640
And it can show you all
the way down to C7, T1.

00:04:30.640 --> 00:04:32.930
But on the original
view, as you've shown,

00:04:32.930 --> 00:04:33.780
we can't see that.

00:04:33.780 --> 00:04:36.540
So what we did for this patient
was get a swimmer's view.

00:04:36.540 --> 00:04:37.570
SAL KHAN: I see.

00:04:37.570 --> 00:04:38.830
So this is adequate.

00:04:38.830 --> 00:04:42.500
And we have this other
slide right over here.

00:04:42.500 --> 00:04:44.200
We have this other
one right over here.

00:04:44.200 --> 00:04:46.325
And why is this one interesting?

00:04:46.325 --> 00:04:48.170
DR. MAHADEVAN: This
is the same patient.

00:04:48.170 --> 00:04:49.991
And now we've taken
that same view

00:04:49.991 --> 00:04:51.990
that we talked about
before, the swimmer's view,

00:04:51.990 --> 00:04:52.430
where you've got--

00:04:52.430 --> 00:04:53.160
SAL KHAN: This is
the same patient

00:04:53.160 --> 00:04:56.005
as this patient right over
here, not this patient over here

00:04:56.005 --> 00:04:56.110
on the right.

00:04:56.110 --> 00:04:56.780
DR. MAHADEVAN: Exactly.

00:04:56.780 --> 00:04:59.020
SAL KHAN: Because that one
looked overall pretty healthy.

00:04:59.020 --> 00:05:00.290
DR. MAHADEVAN: That was
a normal swimmer's view.

00:05:00.290 --> 00:05:02.019
But here is an abnormal
swimmer's view.

00:05:02.019 --> 00:05:03.310
SAL KHAN: It's the same person?

00:05:03.310 --> 00:05:04.440
DR. MAHADEVAN: Same person--

00:05:04.440 --> 00:05:05.950
SAL KHAN: As this one, not
the other swimmer's view.

00:05:05.950 --> 00:05:07.240
DR. MAHADEVAN: Facing
in the same direction,

00:05:07.240 --> 00:05:08.656
in case you want
to test me again.

00:05:08.656 --> 00:05:09.540
SAL KHAN: OK, good.

00:05:09.540 --> 00:05:11.830
DR. MAHADEVAN: And
if you count again,

00:05:11.830 --> 00:05:14.370
starting with the
first vertebra.

00:05:14.370 --> 00:05:15.215
So we go one--

00:05:15.215 --> 00:05:17.332
SAL KHAN: Two-- this
is three right here?

00:05:17.332 --> 00:05:19.165
DR. MAHADEVAN: Three
is this one right here.

00:05:19.165 --> 00:05:22.227
SAL KHAN: Three, oh, it's
a kind of a-- oh, I see.

00:05:22.227 --> 00:05:23.310
This whole thing is three?

00:05:23.310 --> 00:05:25.893
DR. MAHADEVAN: That whole thing
is three right there, exactly.

00:05:25.893 --> 00:05:30.730
SAL KHAN: Four, five,
six, and then seven,

00:05:30.730 --> 00:05:32.552
it looks like
right around there,

00:05:32.552 --> 00:05:34.385
if I'm reading that,
if I see that properly.

00:05:34.385 --> 00:05:35.520
It's a little darker there.

00:05:35.520 --> 00:05:38.770
DR. MAHADEVAN: And the key
important finding there

00:05:38.770 --> 00:05:41.890
is, that as you draw a
line along the anterior

00:05:41.890 --> 00:05:44.000
or the front of all
those vertebral bodies,

00:05:44.000 --> 00:05:47.410
if you were to connect
them just like that.

00:05:47.410 --> 00:05:49.904
SAL KHAN: I'll
draw a dotted line.

00:05:49.904 --> 00:05:50.945
DR. MAHADEVAN: Fantastic.

00:05:50.945 --> 00:05:53.182
SAL KHAN: It looks
pretty all right.

00:05:53.182 --> 00:05:54.640
DR. MAHADEVAN: And
as you go down--

00:05:54.640 --> 00:05:56.310
SAL KHAN: Oh, look
at that, at seven,

00:05:56.310 --> 00:05:58.280
looks like a little
disruption there.

00:05:58.280 --> 00:06:00.840
DR. MAHADEVAN: Exactly,
and it's pushed back.

00:06:00.840 --> 00:06:03.360
And the problem is,
right behind those bones

00:06:03.360 --> 00:06:04.810
is your spinal cord.

00:06:04.810 --> 00:06:08.160
And so in any kind of an
injury like this, potentially,

00:06:08.160 --> 00:06:10.705
could injure your spinal cord
and lead to permanent paralysis

00:06:10.705 --> 00:06:11.250
or weakness.

00:06:11.250 --> 00:06:11.990
SAL KHAN: I see.

00:06:11.990 --> 00:06:12.780
So this is the main thing.

00:06:12.780 --> 00:06:14.397
I guess, there's
two big takeaways,

00:06:14.397 --> 00:06:16.730
at least from this little
short segment, that we've set.

00:06:16.730 --> 00:06:19.271
One is, you've got to make sure
that you have the information

00:06:19.271 --> 00:06:20.390
to make a diagnosis on.

00:06:20.390 --> 00:06:22.040
So for example, this
right over here,

00:06:22.040 --> 00:06:23.180
you couldn't even
do something useful,

00:06:23.180 --> 00:06:24.930
because you're not able to
see the number six and number

00:06:24.930 --> 00:06:25.400
seven.

00:06:25.400 --> 00:06:26.900
DR. MAHADEVAN: Exactly, we
would call it inadequate.

00:06:26.900 --> 00:06:29.631
And we would say, we can't draw
any firm conclusions from that

00:06:29.631 --> 00:06:30.130
actually.

00:06:30.130 --> 00:06:30.726
SAL KHAN: And
that's why you want

00:06:30.726 --> 00:06:31.760
them to get in that
swimmer's position,

00:06:31.760 --> 00:06:34.190
raise the arm from the direction
that you're looking at.

00:06:34.190 --> 00:06:34.940
DR. MAHADEVAN: Correct.

00:06:34.940 --> 00:06:36.690
SAL KHAN: And they'll
lower the other arm.

00:06:36.690 --> 00:06:38.520
And then you can see
something like this.

00:06:38.520 --> 00:06:40.600
And this right over here
is cause for trouble,

00:06:40.600 --> 00:06:42.410
because now you can go
all the way down to seven.

00:06:42.410 --> 00:06:44.020
And you can actually see
that they're not aligned.

00:06:44.020 --> 00:06:44.600
DR. MAHADEVAN: Absolutely.

00:06:44.600 --> 00:06:45.850
And so this is
someone you wouldn't

00:06:45.850 --> 00:06:47.516
let get out of your
emergency department

00:06:47.516 --> 00:06:49.830
without seeing a specialist,
a spine specialist.

00:06:49.830 --> 00:06:52.050
Whereas if you didn't
have that view,

00:06:52.050 --> 00:06:55.060
you might be falsely reassured
that everything was OK,

00:06:55.060 --> 00:06:57.600
when in fact, there's a
serious problem there.

00:06:57.600 --> 00:06:58.980
SAL KHAN: Very cool, very cool.

00:06:58.980 --> 00:06:59.730
Thanks a bunch.

00:06:59.730 --> 00:07:01.690
DR. MAHADEVAN: Thank you.