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18 Cards in this Set
- Front
- Back
What are the three major types of blood vessels? |
Arteries capillaries and veins |
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Arteries |
Carry blood away from the heart Lead to arterioles |
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Arterioles |
Smallest arteries that go to the capillaries |
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Capillaries |
Smallest blood vessels Only area where exchange of gases from the arteries to the veins occur Lead to venules |
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Venules |
Smallest vein that receive blood from capillaries and send it to veins |
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Veins |
Receive blood from venules |
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What are the three layers of a blood vessel |
Tunica intima Tunica Media and Tunica externa |
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Tunica intima |
Also called Tunica interna Innermost tunic right next to the Lumen containing blood Made of endothelium which is simple squamous epithelium Has subendothelial layer made of connective tissue In artery only Has internal elastic membrane |
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Tunica Media |
Middle layer composed of smooth muscle and elastic fibers Function: Lots of control here due to its function of contraction vasocontraction and relaxation vasodilation Only in artery: Has external elastic membrane Thickest layer in arteries |
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Tunica externa |
Strong Outermost layer composed of connective tissue collagen fibers Contains vasa vasorum which Supply blood to blood vessels
thickest layer in the vein
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Why are there valves within the veins but not in arteries? |
Arteries don't need valves since they contract and relax due to the great pushing of the heartbeat which prevents it from flowing back While veins have valves to prevent backflow since the heart does not push it and it doesn't contract |
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What are the different types of arteries |
Elastic arteries muscular Distributing arteries and arterioles |
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Elastic arteries |
The largest artery sense heart pumps blood to them Sometimes called conducting arteries Includes the aorta and its major branches High elastin content let's artery expand and contract smoothly for blood pressure |
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What happens to blood pressure when an artery cannot expand due to clotting? |
BP goes up blood pressure gets high |
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Muscular Distributing arteries |
lie away from the arteries/ distal to the elastic arteries Includes most named arteries such as gastric artery Tunica Media is thick and strong Have internal and external elastic layers which extract and expand |
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Arterioles |
Smallest arteries Not all but larger ones possess all three tunics Diameter is controlled by sympathetic nervous system |
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How big is a Capillary |
Diameter range from 8 to 10 millimeters |
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What are the site specific functions of capillaries |
Lungs- oxygen enters blood carbon dioxide leaves (diffusion) Small intestines- receive digestive nutrients Endocrine glands- pick up hormones Kidneys- remove of nitrogenous wastes |