List and explain the factors that influence blood pressure, and describe how blood pressure is regulated.

Arterial blood pressure reflects two factors:

How much the elastic arteries close to the heart can be stretched (their compliance or dispensability)

The volume of blood forced into them at any time. If the amounts of blood entering and leaving the elastic arteries in a given period were equal, arterial pressure would be constant. Blood pressure rises and falls in a regular fashion in the elastic arteries near the heart.