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What are the three major types of vessels? |
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Definition
Arteries, Capillaries, and Veins |
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Definition
Carry blood away from the heart |
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Definition
Carry blood toward the heart |
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Definition
Contact tissue cells and directly serve cellular needs |
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What are arteries and veins composed of? |
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Definition
Three tunics-interna, media, externa- Lumen Capillaries |
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Term
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Definition
Central blood containing space surrounded by tunics |
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Term
What are capillaries composed of? |
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Definition
endothelium with sparse basal lamina |
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Term
Tunica Interna made of? Lines? |
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Definition
Endothelial layer that lines the lumen of all vessels |
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Term
Tunica interna in large vessels has an extra layer of ________ tissue called |
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Definition
connective tissue called subendothelial |
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Term
Tunica media is made up of? Regulated by? Controls |
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Definition
Smooth muscle and elastic fiber that regulate by sympathetic nervous system Controls vasoconstriction/vasodialation |
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Term
Tunica externa... Another name for it. Made of? Function?
Large vessels contain vaso vasorum |
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Definition
Tunica Adventititia
Made of collagen fibers that protect and reinforce vessels
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Term
Larger vessels of tunica externa contain vas ________ |
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Definition
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Term
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Definition
Vessels of vessels... nourish external tissues of blood vessel walls. |
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Term
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Definition
The joining together of two blood vessels or other tubular structures to furnish a direct or indirect communication between the two structures. |
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Term
What are 2 structural characteristics of the arteries closest to the heart? |
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Definition
Large Lumen Contain elastin in all three tunics Thick walled |
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Term
What does the large lumen, thick wall and elastin function in the arteries near the heart? |
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Definition
Large lumen allow low resistanc conduction of blood Elastin enables the arteries to withstand and smooth out large blodo pressure fluctuations Serve as pressure reservoirs. |
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Term
Muscular arteries function/location? |
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Definition
Deliver blood to body organs. Distal to elastic arteries |
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Term
Muscular arteries structural characteristics? Major function? |
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Definition
Thick tunica media with more smooth muscle. Active in vasoconstriction |
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Term
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Definition
Smallest arteries which lead to capillary beds |
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Term
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Definition
Control flow into capillary beds via vasodilation and constriction |
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Term
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Definition
Smallest blood vessels which allow only a single RBC to pass at a time. |
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Capillaries structural characteristics Walls consist of? |
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Definition
thin tunica interna (one cell thick) Pericytes on the outer surface stabilize their walls. |
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Term
What are the 3 types of capillaries? |
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Definition
1.Continuous 2.Fenestrated 3.Sinusoids |
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Term
Where are contiuous capillaries found |
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Definition
Abundant in the skin and muscles and the brain |
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Term
Structural characteristics of contiuous capillaries? Endothelial cells, Adjacent cells, Intercellular clefts |
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Definition
Endothelial cells provide an uninterupted lining Adjacent cells are connected with tight juctions Intercellular clefts allow the passage fo fluids |
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Term
What is the basement membrane composed of? |
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Definition
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Term
What do the continous capillaries of the brain make up? What structural characteristic sets it apart? |
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Definition
Constitute the blood brain barrier They have tight junctions completely around the endothelium |
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Term
Where are fenestrated Capillaries found? Function? |
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Definition
Small intestines, Endocrine glands, Kidneys Active capillary absorbtion or filtrate formation occurs. |
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Term
What does fenestrated mean. Size of fenestrations |
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Definition
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Term
Fenestrated capillaries characteristics |
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Definition
An endothelium riddled with pores Greater permeability than other capillaries |
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Term
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Definition
highly modified, leaky, fenestrated capillaries with LARGE lumens. |
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Term
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Definition
Liver, bone marrow, lymphoid tissue other endocrine organs |
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Term
Sinusoid function What speed does blood flow in sinusoids? |
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Definition
Allow large molecules such as proteins and blood cells to pass between the blood and surrounding tissues. Sluggishly |
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Term
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Definition
a microcirculation of interwoven networks of capillaries consisting of vascular shunts and true capillaries. |
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Term
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Definition
metarteriole-throughfare channel connection an arteriole directly with a postcapillary venule |
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Term
True Capillaries Number per capillary bed? |
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Definition
10 to 100 per capilary bed, capillaries branch off the metarteriole and return to the throroughfare channel at the distal end of the bed. |
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Term
Precapillary sphincters function? Composed of? |
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Definition
a valve that can be stimulated to contract thus halting the flow of blood to the capillary bed. Smooth muscle |
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Term
Blood flow from artery to vein |
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Definition
goes from a terminal arteriole to a postcapillary venule |
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Term
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Definition
cuff of smooth muscle that surrounds each true capillary and regulates blood flow into the capillary |
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Term
Precapillary sphincter blood flow regulation? |
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Definition
Vasomotor nerves and local chemical conditions. |
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Term
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Definition
allow fluids and WBCs to pass from the blood stream to tissues capillary beds unite |
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Term
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Definition
Smallest venules composed of endothelium and a few preicytes |
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Term
Large venules Contain what kind of tunica? |
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Definition
have one or two layers of smooth muscle (tunica media) |
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Term
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Definition
Formed when venules converge |
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Term
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Definition
Thin tunica media Thick tunica externa consisting of collagen fibers and elastic netwarks |
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Term
Two special characteristics of veins which allow them to return blood to the heart. |
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Definition
1.Large diameter lumens which allow for little resistance to flow 2.Valves which prevent backflow |
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Term
Venous sinuses Define 2 examples |
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Definition
Specialized flattened veins with extremely thin walls Coronary sinus of the heart and dural sinuses of the brain |
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Term
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Definition
Merging blood vessels, more common in veins than arteries. |
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Term
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Definition
provide alternate pathways for blood to reach a given body region. |
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Term
Venous anastamosis Example? |
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Definition
veins interconnect Example dorsum of hand |
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Term
Venous anastamosis Example? |
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Definition
veins interconnect Example dorsum of hand |
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