NEET PG DENTAL EXAM

Detailed explanation-1: -Arteries have smaller lumens than veins, a characteristic that helps to maintain the pressure of blood moving through the system. Together, their thicker walls and smaller diameters give arterial lumens a more rounded appearance in cross section than the lumens of veins.

Detailed explanation-2: -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.

Detailed explanation-3: -The arteriolar lumen regulates the flow of blood through the capillaries. Venules are the smallest veins and receive blood from capillaries. They also play a role in the exchange of oxygen and nutrients for water products. There are post-capillary sphincters located between the capillaries and venules.

Detailed explanation-4: -Vasodilation is the widening of blood vessels as a result of the relaxation of the blood vessel’s muscular walls. Vasodilation is a mechanism to enhance blood flow to areas of the body that are lacking oxygen and/or nutrients.