Term
| What are the 3 layers that form the vessel wall? |
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Definition
- tunica intima - lines the sindies of the vessel and is exposed to blood (endothelium + basement membrane)
- tunica media - the thickest; smooth muscle + collagen + some elastin
- tunica externa - outermost layer, loose connective tissue + vasa vasorum (small vessels)
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Term
| How does the anatomy of veins and arteries differ? what about capillaries? |
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Definition
| Arteries have more elasticity and veins have valves; capillaries only have ednotehlium and basement membrane |
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Term
| What are the three sensory receptors related to the maintainence of BP and what are their functions? |
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Definition
- carotid sinuses - baroreceptors (pressure sensors) that respond t ochanges in blood pressure; have a thin tunica media and many glossopharyngeal nerve fibers. a rise in BP stretches the tunica media and stimulates the nerve fibers; the nerves tranmits signals to vasomotor and cardiac centers of the brainstem, and brainstem responds by lowering HR and dilating vessels
- carotid bodies - receptors innervated by sensory fibers of the vagus and glossopharyngeal nerves;; chemoreceptors that monitor changes in blood composition and adjust breathing to stabilize blood pH and levels of O2 and CO2
- aortic bodies - in aortic arch, does the same as carotid bodies
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Term
| What is an aneurysm? where are they most common? |
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Definition
- weak point in an artery or in the heart wall; forms a thin-walled bulging sac that pulsates w/ each beat of the heart and may eventually rupture or cause pain or death by putting pressure on brain tissue, nerves, veins, etc
- abdomina aorta renal arteries and brain
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Term
| In a resting adult, is there more blood in the veins or arteries? |
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Definition
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Term
| What is the simplest circulatory pathway? where can this be found? |
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Definition
- artery --> cap. bed --> vein
- found in pulmonary circuit, in lungs
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Term
| what is a portal system? where can this be found? |
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Definition
- artery --> cap. bed --> cap bed --> vein
- kidneys or b/t hypothalamus and pituitary
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Term
| where can you find the hepatic portal system? |
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Definition
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Term
| what is an anastomosis? where are arteriovenous anastomoses found? |
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Definition
- two veins or arteries merge with each other w/o intervening cap. beds
- places prone to frostbite
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Term
| Where can you find arterial anastomoses? |
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Definition
| coronary circulation, joints |
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Term
| Where would you find venous anastomoses? |
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Definition
| drainage from organ; this type of anas. is most common |
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