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23 Cards in this Set
- Front
- Back
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What are the functions of the Cardiovascular system? |
1. PRIMARY: Deliver blood to the tissues 2. Provide essential nutrients to cells for metabolism 3. Remove waste products from the cells |
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What is the pump of the CV system that generates pressure? |
The heart |
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What carries blood from heart to body tissues? |
Vessels |
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What are the homeostatic functions of the CV system? |
- Deliver endocrine hormones from glands to tissues
- Thermoregulation
- Adjustments to alter physiologic states such as hemorrhage, exercise, postural changes. |
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How are the atrium and ventricles of each side of the heart connected? |
The AV valve |
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What kind of blood does the left side of the heart pump? |
Oxygenated blood to systemic circulation |
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What kind of blood does the right side of heart pump? |
Deoxygenated blood to the pulmonary circulation |
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What is cardiac output? |
Rate at which blood is pumped out from either ventricle, work in series |
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What is the formula for Cardiac Output? |
Cardiac Output = Heart rate x stroke volume |
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What is venous return? |
Rate at which blood returns to the heart. Equal on left and right sides |
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Cardiac output = venous return means what? |
A steady state. Maximizing venous return to maximize cardiac output. |
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List organs and % if CO they use. |
Liver, GIT, Kidneys, Skeletal muscle (25%) > Brain (15%) > Heart, skin (5%) |
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List the 3 ways we can change CO |
1. If CO is constant, adjust the flow to an organ by altering resistance (i.e. increase blood to one by decreasing blood to another)
2. Hold the % distribution to organs constant and adjust flow to all by increasing overall CO (i.e. increase to all)
3. Increase CO as well as alter % distribution to organs by altering resistance to flow.
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Explain. |
Smooth muscle: contraction and dilation Elastic tissue: stretching and recoiling - Aorta: mostly elastic - Arteries, arterioles: some elastic tissue and mostly smooth muscle - Veins, Vena Cava: mostly smooth muscle and less elastic tissue. - Capillaries: endothelium - Venules: bit of everything |
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Describe arteries |
- transport oxygenated blood - thick walls - extensive elastic tissue, smooth muscle and connective tissue - under high pressure - blood rapidly flows through |
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Describe arterioles |
- diameters less than 200 um - SITE OF HIGHEST RESISTANCE TO BLOOD FLOW - +++ smooth muscle - Innervated by adrenergic nerve fibers - Alpha1 receptor activation to most organs produces constriction - Beta2 receptor activation to skeletal muscles produces dilation |
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Describe capillaries |
- thin-walled structure with single endothelial cell layer - Where gas, water, ions, and nutrients exchanged between blood and tissues - Selective perfusion. Determined by tone on arterioles and pre-capillary sphincters (smooth muscle bands) |
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Describe venules and veins |
- collect and carry blood from capillaries to heart - thin walled - elastic tissue, smooth muscle, connective tissue - less elastic tissue than arteries - can hold A LOT of blood - high compliance (i.e. change in volume with change in pressure) |
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Which structure has the greatest surface area? |
Capillaries. Then veins > arterioles > arteries |
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Which structure has the most blood volume at any one time? |
Veins! 2/3 of blood volume. Then arteries > capillaries |
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What percent of total blood volume does the systemic circulation carry? |
About 80% at any one time |
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What percent of total blood volume does the pulmonary circulation carry at any one time? |
About 20% |
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How do veins prevent back flow of blood? |
- "valves" that encourage one-way flow - movement and skeletal muscle contraction to "milk"/compress vein in the direction of the heart |
