Bio 2341 Study Aid to Accompany Chapter 19: Blood Vessels
Focus on Figure 19.1 Generalized structure of arteries, veins, and capillaries. The structure of the vessels makes understanding the role each one plays easier to learn. Note, the vessels not only deliver blood efficiently but also control blood pressure, direction of blood flow, and capillary exchange.
Figure 19.8 Major factors enhancing cardiac output is an excellent summary of factors stimulating changes in cardiac output. The figure is then ‘linked’ to Figure 19.11 Factors that increase MAP because of the direct relationship between cardiac output and MAP. If you can interpret these two figures and Figure 19.10 Direct and indirect mechanisms for renal control of blood, then you have learned at a very high level.
The dynamics of blood flow is somewhat complicated. Always keep in mind that the heart must generate enough force to create a pressure gradient causing blood to flow against frictional forces exerted by vessel walls. Blood is a liquid and its properties also affect friction and flow. Since many of the forces initiating and resisting flow are relatively constant in an adult human, those factors that are manipulated by the body to alter the BP and the flow of blood are cardiac output, peripheral vasoconstriction/vasodilation, and blood volume.
NOTE: Part 3 of Chapter 19 (721-744) provides “maps” of arteries and veins that should be used as a resource in the lab. You will not be tested on the names of arteries and veins on the lecture test.
Vocabulary is needed to understand and explain concepts. Sample vocabulary includes: peripheral vascular shunt stethoscope thermoregulation metarteriole sphygmomanometer capacitance microcirculation Poiseuille’s Law arteriovenous precapillary sphincters vasoconstriction anastomosis intercellular cleft vasodilation thoroughfare channel caveolae critical closing pressure precapillary capillary hydrostatic pressure baroreceptors lumen capillary colloid osmotic pressure chemoreceptors tunic/tunica bulk flow perfusion tunica intima interstitial fluid hydrostatic pressure autoregulation tunica media interstitial fluid osmotic pressure myogenic control tunica externa net filtration pressure metabolic control basal lamina peripheral resistance renal vasomotor/vasomotion viscosity angiotensinogen subendothelial diameter angiotensin pericytes laminar flow aldosterone fenestrations/fenestrated turbulent flow renin diaphragm hematocrit atrial natriuretic peptide sinusoid sounds of Korotkoff
Major concepts that you must remember and understand include: The unique roles of arteries, capillaries and veins. The names of blood vessel subdivisions and their structure and function. The names of capillary types and their structure and function. The role of the veins as a reservoir for blood. Measurements for blood pressure and heart rate, calculation of mean arterial pressure. Changes in blood pressure and flow in vessels based on vessel size and distance from heart. Actions and activities that increase venous return. Local control over blood flow to capillary beds using precapillary sphincters. Structures in veins facilitating blood return to heart. Typical pressures encountered in various blood vessels. Neurological controls over cardiac function and blood vessel diameter. Hormonal controls over cardiac function and blood vessel diameter. Myogenic controls over blood vessel diameter. Kidney involvement in blood pressure control. Capillary exchange and fluid loss to tissues.
Concepts you should learn on your own: Atherosclerosis
Concepts you can skip: Developmental aspects of blood vessels.