NEET PG DENTAL EXAM

Detailed explanation-1: -Veins carry unoxygenated blood towards the heart, away from tissues at low pressure so the lumen is large. Blood moves more slower and often against gravity so valves and a larger lumen ensure it is still transported efficiently. Capillaries have the smallest lumen but relative to their size the lumen is quite large.

Detailed explanation-2: -Each type of vessel has a lumen-a hollow passageway through which blood flows. Arteries have smaller lumens than veins, a characteristic that helps to maintain the pressure of blood moving through the system.

Detailed explanation-3: -The two largest veins in the body are the superior vena cava, which carries blood from the upper body directly to the right atrium of the heart, and the inferior vena cava, which carries blood from the lower body directly to the right atrium. The inferior vena cava is labeled in the figure below.