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What function does blood perform?
Carry oxygen throughout the body
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What % of human's body weight does blood account for?
8%
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What is blood composed of?
Fluid (plasma) along with several types of cells (erythrocytes, leukocytes, plaetlets)
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What are the components of plasma?
- Mostly water (90 - 93%)
- Proteins;
- Electrolytes;
- Gases;
- Nutrients;
- Waste products;
- Various hormones
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98.5% of oxygen transported in th blood is bound to what?
Hemoglobin, a protein found only in erythrocytes (red blood cells)
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What is the most abundant type of cells found in the blood, and what % of the body's blood cells do they make up?
Erythrocytes -- red blood cells. Make up 99% of blood's cells
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What does hemoglobin carry?
Carries about 30% of the carbon dioxide transported by the blood
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What is hematocrit?
Measure of the percentage of the blood's volume that is composed of erthrocytes.
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What is the average hematocrit in women and men? Why are they different?
- Women = 42%;
- Men = 45%;
- Difference exists because male hormone testoterone affects production of erythrocytes
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What are other effects of lower hematocrit levels in women?
- Reduced hemoglobin content;
- About 14 g/1000 mL of blood compared to men's 16 g/100 mL of blood
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What are leukocytes where are they located and what's their function?
- White blood cells;
- Part of body's immune system;
- Function os to destroy potentially infectious agents the enter the body
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What are platelets and what is their function?
- Fragments of larger cells;
- Function is to accumulate and form a plug where damage has occured to the wall of the blood vessel to prevent loss of blood
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What effects does exercise have on the blood?
- Induces hyperemia;
- Cardiovascular drift
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What is hyperemia and what does this do for exercise?
- Increase in the volume of blood delivered to the working muscles;
- Allows:
- Greater delivery of oxygen and nutrients;
- Efficient removal of carbon dioxide and metabolic by-products such as lactate
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What is cardiovascular drift and what does this do for exercise?
- Movement of plasma out of the blood vessels into surrounding tissue;
- Prevents overheating of the body by having more water available for sweating;
- Increases during exercise in hot environments;
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What does cardiovascular drift cause a decrease in and what is the result?
Causes a decrease in total volume of blood in the vasculature, resulting in decreased stroke volume and increased heart rate even though exercise remains constant
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What is hemoconcentration?
- Another result of cardiovascular drift;
- Causes elevation in hematocrit and hemoglobin values
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Long term training is associatd with what positive adaptations of the blood?
- 1) Production of erythrocytes significantly increases
- 2) Plasma volume increases resulting in hemoglobin and hematocrit decrease
- 3) Oxygen-carrying capacity of blood increases because of 1&2
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What is runner's anemia?
The result of decreased hemoglobin and hematocrit in well-conditioned athletes. Should not be considered a negative.
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What are advantages of increased plasma in trained individual?
- 1) At rest, higher SV and lower HR
- 2) During exercise, enhances capacity for thermoregulation (ie running in hot/cold environments)
- 3) During submaximal training, higher SV and lower HR than untrained individuals
- 4) Max SV and cardiac output are more impressive in trained individuals
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