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15 Cards in this Set
- Front
- Back
Striated Fibers |
On myocardium interconnect to make portions of the heart contract in a unified manner |
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Hear functions as 2 separate pumps: |
-One receives blood from the body and pumps it to the lungs for aeration (pulmonary circulation) -The other receives oxygenated blood from the lungs and pumps it throughout the systemic circulation |
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Pressure Changes |
Created during the cardiac cycle and act on the heart's valves to provide one-way blood flow in the vascular circuit |
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Pressure changes within arterial vessels |
Surge of blood with ventricular contraction creates these changes. Ventricular contraction generates systolic blood pressure, the highest pressure during the cardiac cycle. Diastolic pressure represents the lowest pressure before the next ventricular contraction |
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Dense capillary network |
Provides a large and effective surface for exchange of chemicals between the blood and surrounding tissues. These tiny diameter blood vessels possess autoregulatory capacity to adjust blood flow in response to the tissue's metabolic activity |
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Venous Tree |
Contains largest portion of central blood volume at rest, but an increase in venous tone (venoconstriction) probs contributes little to the redistribution of blood during exercise |
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Skeletal muscle action |
Skeletal muscles compress and relax the veins imparting considerable energy to facilitate venous return. This muscle pump provides additional justification for active recovery immediately following vigorous exercise |
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High blood pressure |
1 of 3/4 people experience chronic high blood pressure Hypertension imposes a chronic cardiovascular stress that eventually damages arterial vessels and leads to arteriosclerosis, heart disease, stroke and kidney failure |
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Systolic Blood Pressure Diastolic Blood Pressure |
Increases in proportion to O2 consumption and blood flow during graded exercise. Remains relatively unchanged/decreases slightly At the same exercise levels, upper body exercise produces a greater rise in systolic pressure than leg exercises |
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Blood pressure after exercise |
Decreases below the preexercise level and may remain lower for up to 12hrs |
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Isometric, free-weight and hydraulic resistance exercises: |
Peak systolic and diastolic blood pressures mirror a hypertensive state. Performing high-intensity resistance exercises pose a risk to individuals with hypertension/heart disease |
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At rest |
Myocardium extracts approx 80% of the O2 flowing through the coronary arteries. Increase in coronary blood flow primarily provides for myocardial O2 need in exercise |
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Myocardium |
Requires continual and adequate O2 supply. Coronary blood flow impairment initiates chest pains (angina); blockage of a coronary artery causes irreversible damage to the hear muscle (myocardial infarction) |
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Myocardial workload: |
Can be estimates from the rate-pressure product (heart rate x systolic blood pressure) |
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Energy supply to maintain myocardial function: |
Comes from metabolism of glucose, fatty acids,and circulating lactate. Their percentage use varies with severity and duration of exercise and the individual's training status |