ZoologyThe figure shows blood circulation in humans with labels A to D. Select the option which gives correct identification of label and functions of the part.

The figure shows blood circulation in humans with labels A to D. Select the option which gives correct identification of label and functions of the part.

A
B - Capillary-Thin without muscle layer and wall two cell layers thick
B
C - Vein-Thin walled and blood flows in jerks/spurts
C
D - Pulmonary vein-Takes oxygenated blood to heart, ${PO}_{2}$ = 95 mmHg
D
A - Artery-Thick walled and blood flows evenly

Solution:

D - Pulmonary Vein-Takes oxygenated blood to heart, PO₂= 95 mmHg

C - Vein-Thin walled and blood flows evenly.

B - Capillary-Thin without muscle layer and wall one cell layer thick (squamous epithelium).

A - Artery-Thick walled and blood flows in jerks.