Physiology 2130 Lecture Notes - Lecture 9: Blood Vessel, Capillary, Aorta
24 Mar 2019
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Document Summary
These vessels are the site of highest resistance in the circulation and help regulate blood flow to an organ: blood velocity is lowest in capillaries while their total cross-sectional area is highest in circulation. This helps maximize exchange of substances across blood vessels: blood pressure and cross-sectional area decreases while blood velocity increases in the venules and veins. These vessels return blood back to heart while storing a large percentage of tbv. Flow is slower at the edges and faster in the center: therefore to examine blood flow through a vessel we look at pressure gradient and resistance that the fluid encounters, where, flow = (p1 p2)/ resistance. 9. 10 resistance to blood flow: factors that effect resistance are, thickness or viscosity of the fluid in the tube affects resistance. Viscosity of blood does not change in general: length of vessel affects resistance.
