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341 Chpt 15
Blood vessels
| Question | Answer |
|---|---|
| Functions of blood vessels | Carry blood, regulate blood flow, regulate body temperature |
| Types of vessels | arteries, arterioles, capillaries, venules, veins |
| Systemic circulation | oxygenated blood from left ventricale, arteries, caplillaries, to tissues |
| Subdivisions of systemic circualtion | Coronary, cerebral, hepatic portal |
| Pulmonary circulation | Deoxygenated blood from right ventricle to lungs |
| Portal means | Blood travels through 2 sets of caps before reaching heart |
| 3 layers of arteries | t. externa, t. media, t. interna |
| Elastic artery | Largest; t. media-elastic fibers>smooth muscle |
| Muscular artery | T. media-smoot muscle>elastic fibers; regulate blood flow |
| Arterioles | Deliver blood to caplillaries |
| How does arterioles help in temperature regulation? | By vasocontricting (saves heat) or vasodialation (releases heat) of the arterioles near the skin |
| Capillaries | Only have endothelium and basement membrane - three types |
| Three types of capillaries | continuous, fenestrated, sinusoids |
| Continuous capillaries | Only gaps are between neighboring cells, and are the most common |
| Fenestrated capillaries | Plasma membrane has holes. In kidneys, sm. intestine, and some glands. |
| Sinusoids | Very large openings, incomplete basement membrane so proteins and cells can pass through. Found in liver and spleen. |
| Veins | T. interna, and t. media very thin and t. externa very thick - not stretchy |
| Venules | Recieves blood from capillaries and drains the blood into veins. No t. externa and very thin walls |
| Where is most of the blood in the body at any given time? | In the veins and venules |