MICROANATOMY

Detailed explanation-1: -When veins constrict, their capacity to hold blood is reduced, allowing more blood to return to the heart from which it is pumped into the arteries. As a result, blood pressure increases. Conversely, when veins dilate, their capacity to hold blood is increased, allowing less blood to return to the heart.

Detailed explanation-2: -In general, blood pressure decreases from arteries to veins, and this is because of the pressure overcoming the resistance of the vessels. The greater the change in resistance at any point in the vasculature, the greater the loss of pressure at that point.

Detailed explanation-3: -Veins carry blood back to your heart from the rest of your body. The pressure of the blood returning to the heart is very low, so the walls of veins are much thinner than arteries.

Detailed explanation-4: -Explanation: In the general circulation, the highest blood pressure is found in the aorta and the lowest blood pressure is in the vena cava.