2nd constriction in oesophagus is seen at the following site -
There are 4 esophageal constrictions. They are at 15cms, 22.5cms, 27.5cms and 37.5 to 40 cms, from the incisors. The second constriction is due to crossing of arch of aorta.
Where it crosses left main bronchus
Crossing of aorta
At pharyngoesophageal junction
Where it pierces the diaphragm