Infection of lower lip first reaches blood stream through?
The pathway of spread of intection from lower lip to blood is:
Lip ⇾ Sub mental and submandibular lymph nodes ⇾ deep cervical lymph nodes ⇾ Left and right jugular lymph trunk ⇾ from left jugular trunk thoracic duct & from right at the junction between IJV and subclavian vein ⇾ IJV + subclavian vein = Brachiocephalic vein and two brachiocephalic vein join to form superior vena cava.
Or directly, we can say infection from any tissue reached the blood stream via venous drainage rather than arterial supply.
Inferior labile artery
Superior labile artery
Pterygoid plexus
Brachiocephalic vein