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Funtions
- Delivers Oxygen and nutrients to body organs
- removes waste products of merabolism from tissue cells
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Major Components
- circultory system
- large and small elastic vessels
- trnasports blood throughout body
- Heart
- hollow muscular organ
- pumps blood thorughout body
-
blood vessels
- arteries
- from heart to capillaries
- usually oxygenated
- aterioles = small ateries (.3 mm)
- Veins
- to heart from capillaries
- usually deoxegenated
- venules = small veins
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Capillaries
- interchange of nutrients and celluar waste
- typical count: 10 billion capilaries
- total surface areas 500 square meters
- most cells < 20 micorns from capillary
- Capillary dimensions
- walls .5 micron thick
- diameter about 7-9 microns
- precapillary shineters control flow
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heart
- 2.6 billion heartbeats/lifetime
- 70 bpm x 525,000 min/yr x 70 yr
- 46 million gallons pumped in a lifetime
- 1.25 g/min x 525, 00 min/yr x 70
- size of two fists
- 7-15 ounces
- shaped like cone
-
heart structure
- myocardium
- heart muscle
- straited, involuntary
- pericardium
- sac around heart
- chambers
- atria(rt and lt)
- ventricles
- septum between
-
heart valves
- valves
- atrioventricular valves
- tricuspid, bicuspid(mitral)
- chorade tendinae
- connective tissue fibers
- anchor valves to ventricle walls
- semilunar valves
- crescent shaped cusps(3)
- seperate heart from circulatory system
- pulmonic aortic
-
heart vessels
- veins
- superior, inferior vena cava
- pulmonary veins
- arteries
- aorta
- pulmonary artery
-
vascular pathways
- pulmonary circuit
- rt ventricle---> lungs---> left atrium
- pulmonary artery, pulmonary veins
- sytemic circuit
- if ventricle--->body--> rt atrium
- largest artery = aorta
- largest viens = inferior, superior vena cava
-
blood vloume %
- large veins-39%
- small veins, venules-25%
- large arterties-8%
- small arteries- 5%
- capillaries, arterioles-7%
- pulmonary vessels-9%
- heart-7%
-
blood flow
- heart
- most important in arterial flow
- high pressure (120 mmhg)
- muscle contraction
- most important in venous flow
- valves prevent back flow
- respiration
- helps venous flow
- thoracic pressure falls
- abdominal pressure rises
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