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Ch.21Blood vessels
Blood vessels and hemodynamics
Question | Answer |
---|---|
largest artery in the body | aorta |
small network of capillaries in the smooth muscle layer of the vessel | vasa vasorum |
three layers to a blood vessel | Tunia intama/interna, media (smooth muscle), and externa (expansive connective tissue and elastic fibers). |
2 types of arteries | Elastic (>1 cm. diameter, recoil. ex:aorta) and Muscular (mostly tunica media/smooth muscle, ex:brachial) |
what are the layers like in arteries? | Intama just a few cell layers thick. Media the largest. |
Layers in arterioles? Other name? | Thin intama (a few cell layers thick) and one or two cell layers thick of media. "Resistance vessels" because they regulate how much blood goes into capillaries. |
Layers and types of capillaries. Other name? | 1 cell layer thick intama adhering to basement membrane (on outside). Types: Continuous (skeletal and smooth muscle, brain, lungs), Fenestrated (brain and kidneys), and Sinusoidal (liver, glands, spleen). |
Layers in venules. Function? | T. interna and T. media. WBC emigration. |
Layers of veins. | Thin T. interna and t. media. Thick externa. |
Describe valves in veins. | Valves point toward the heart. Don't like pressure. |
Valvular defect. | Vericose veins (congenital or from mechanical stress/prolonged standing) caused from leaking venous valves allowing back flow of blood from the deep veins to superficial veins. Moving and exercise help prevent. |
Double sets of veins that escort arteries and connect to one another via venous channels. | Anastomosis. |
Difference between systolic and diastolic numbers. Why significant? | Pulse pressure. High number might mean open ductus arteriosis. |
4 types of shock. | Hypovolemic (decreased blood volume), cardiogenic (defunct pump), vascular (inappropriate vasodialation), obstructive (blood flow stopped = embolism?) |
What is shock? | Failure of the cardiovascular system to deliver sufficient oxygen to meet the body's needs. |
Homeostatic response to shock. | 1)Activation of sympathetic ANS (vasoconstriction, increased BP, increased contractility, increased epi and norepi.2)Secretion of antidiuretic hormone.3)Release of local vasodilators. |
Pre-hypertension is what currently? | 126/86 |