Vasculature handout 1 per page

• To explain how physical factors affecting the cardiovascular system (e.g. flow, pressure, tension, vessel radius, blood viscosity, and the velocity of flow) are interrelated and the practical haemodynamic implications of these.

T = PR

(tension = pressure x radius of vessel)

as the radius increases the tension should increase

viscosity increases when velocity decreases static blood has 100x more viscosity than moving

• To describe how blood flow through the microcirculation is regulated at the tissue level, via both short-term (acute) and long-term mechanisms.

at local level there are tissue specific vasodialators or constrictors

e.g. constrictor = noradrenaline/adrenaline

e.g. dilator = adenosine (from ATP breakdown)

if a tissue is undergoing a high metabolic state of action adenosine will be produced in abundance as it is the breakdown from use of ATP this causes dilation of vessels and encourages oxygen to flow in