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53 Cards in this Set
- Front
- Back
5 types of vessels |
1. arteries 2. arterioles 3.capillaries 4. venules 5. veins |
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describe an artery |
- they carry blood AWAY from the heart to body tissues |
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what are the two large arteries |
the aorta and the pulmonary trunk |
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describe an arteriole |
- very small, microscopic artery that delivers blood to capillaries -regulate blood flow from arterioles into capillaries |
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describe capillaries |
- microscopic vessels that connect arterioles to venules - known as exchange vessels - they permit the exchange of nutrients and wastes b/t the bodys cells and the blood |
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what is the structure of capillaries |
- consist of a layer of endothelium that is surrounded by basement membrane |
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what is capillary exchange |
the movement of substances into and out of capillaries |
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describe a venules |
- little veins - when several capillaries unite, they form venules - walls are thinner near the capillary end and thicker as they progress towards the heart
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describe a vein |
- has valves - carries blood back to the heart from tissues - contain tunica interna and media which are thinner than arteries - and tunica externa which is thicker than arteries
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what is vasoconstriction |
- the decrease in the diameter of the lumen of a blood vessel
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what is vasodilation |
- increase in the diameter of the lumen |
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what is anastomoses |
- 2 or more branches of arteries, veins, or venuels joining to supply the same area |
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what is collateral circulation |
- an alternate route taken by blood though an anastomosis. |
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what is lumen |
- the hollow space of a artery through which blood flows - the lumen of a vein is thicker then that of an artery |
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what are the 3 layers of an artery |
- tunica interna- inner layer, - tunica media - middle layer and thickest - tunica externa- outer layer elastic and collagen fibres
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what are elastic arteries |
- the largest diameter arteries - contain high proportion of elastic fibres in their middle layer - walls are relatively thin - help propel blood onward while ventricles are relaxing ex. aorta, brachiocephalic and common carotid |
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what are muscular arteries |
- the medium sized arteries - tunica media contain more smooth muscle - capable of greater vasoconstriction and vasodilation to distribute blood |
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what are arteries that have divided into their smaller parts |
arterioles |
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how is blood flow regulated from the arteries to the capillaries |
by regulating resistance |
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microscopic blood vessels are located between what two vessels. |
arteriole and venule |
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what is the function of exchange vessels? |
they exchange nutrients and waste b.t the blood and tissues through interstitial fluid |
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what is blood flow? |
- the volume of blood that flows through a tissue at any given time |
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define blood pressure |
- contraction of the ventricles generates BP, the pressure excerpted by blood on the walls of blood vessels |
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when is blood pressure highest |
- in the aorta - in large systemic arteries |
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what unit is blood pressure measured? |
mmHg millimeters of mercury |
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how do you measure blood pressure? ( how is it written)
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systolic ( ventricular contraction) ( highest pressure) over diastolic ( ventricular relaxation) (lowest pressure)
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what is normal blood pressure |
normal BP 120/80 mmHg (120 systolic/ 80 diastolic) |
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what is pulse pressure |
- the difference bt systolic and diastolic pressure |
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what is normal pulse pressure |
- normal is 40mmHg |
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what is circulation time? how long does it take? |
- is the time it takes blood to pass from right a to left and back - approc 1min |
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describe in detail systemic circulation (3) |
- the route the oxygenated blood flows from the left ventricle through the aorta to all the organs
- the route the deoxygenated blood takes when it returns to the right atrium
- all veins in the systemic circulation drain into the superior vena cava, inferior vena cava or the coronary sinus |
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what are the locations of these parts of the aorta -ascending aorta -arch of the aorta -thoracic aorta -abdonminal aorta
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aorta ascending aorta arch of the aorta ends @ T4 thoracic aorta @ T4-T12 abdominal aorta @ T12-L4 |
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what are the branches of the ascending aorta |
-the left and right coronary arteries:
- brachiocephalic trunk splits into the right common carotid artery, right subclavian artery - left common carotid - left subclavian |
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what are the veins of systemic circulation
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- coronary sinus- great cardiac vein, middle cardiac vein, smaller cardiac vein. - inferior vena cava - superior vena cave |
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what is the azygos vein |
- The azygos vein is a vein running up the right side of the thoracic vertebral column.
-if one vena cava is blocked it provides an alternative path for blood to the right atrium
- allowing the blood to flow between the 2 venue cava |
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what are the branches of the azygos vein |
- hemiazygos (left) - accessory hemiazygos (branches off the left) |
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what is pulmonary circulation |
- the flow of deoxygenated blood from the right ventricle to the lungs
- the return of oxygenated blood from the lungs to the left atrium
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which arteries are the only ones to carry deoxygenated blood? |
- the right and left pulmonary arteries
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which veins are the only ones to carry oxygenated blood? |
- the right and left pulmonary veins |
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what is fetal circulation |
- fetal circulation is the circulatory system of the fetus - it contains special structures that allow the developing fetus to exchange material with the mother |
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what function does the placenta have in fetal circulation |
-its where exchange of materials b/t mother and fetus occur |
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what is the function of the umbilical cord in fetal circulation |
- contains the umbilical arteries and vein - connects the fetus to the placenta |
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what are the structures that help the fetus exchange material with its mother? |
- placenta -umbilical cord
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what is the function of the umbilical arteries? |
- blood passes from the fetus to the placenta - this eliminates co2 and wastes |
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what is the function of the umbilical vein? |
- brings oxygenated blood from the placenta to the fetus |
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what is the function of the foremen ovale |
- is the opening b.t the left and right atrium so blood does not have to pass into the right ventricle and the lungs -the blood that is passed into the right ventricle is pumped into the pulmonary trunk - closes shortly after birth |
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what is the ductus arteriosus? |
- is a vessel that connects the pulmonary trunk with the aorta so that most blood bypassees the fetal lungs -becomes the ligamentum arteriosum after birth
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what is the function of the valves in veins? |
- to prevent the back flow of blood |
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what is the tunica interna composed of
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- composed of endothelium - a basement membrane - elastic tissue called internal elastic lamina |
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what is the tunica media composed of
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- smooth muscle and elastic tissue |
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the tunica externa is composed of |
- mostly elastic and collagen fibres |
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systemic circulation includes what? |
- arteries and arterioles that carry blood containing o2 and nutrients from the left ventricle to systemic capillaries - left side of the heart |
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pulmonary circulation includes what (3) and what is the path of the flow |
- the pulmonary trunk, right pulmonary artery and left pulmonary artery - flow of deoxygenated from the right ventricle to the air sacs of the lungs and the return of oxygenated blood to the left atrium |