Blood Flow and Delivery Flashcard

Front

What is one factor that affects the volume of blood delivered to tissues?

Back

Redistribution of blood flow

Answer explanation

Redistribution of blood flow is crucial as it directs blood to areas with higher metabolic needs, thus affecting the volume delivered to tissues. Other factors like heart rate and blood pressure also play roles, but redistribution is key.

Front

How does the redistribution of blood flow increase blood delivery to active tissues?

Back

By dilating arteries

Answer explanation

Dilation of arteries increases blood flow to active tissues by reducing resistance and allowing more blood to reach those areas, enhancing oxygen and nutrient delivery during increased activity.

Front

What percentage of cardiac output is directed to working skeletal muscle at rest?

Back

15-20%

Answer explanation

At rest, approximately 15-20% of cardiac output is directed to working skeletal muscle. This percentage reflects the lower metabolic demand of muscles when the body is not engaged in intense physical activity.

Front

During maximal exercise, what percentage of cardiac output is directed to working skeletal muscle?

Back

80-85%

Answer explanation

During maximal exercise, the body prioritizes blood flow to working skeletal muscles, directing about 80-85% of cardiac output to support increased demand for oxygen and nutrients.

Front

Which organs experience decreased blood flow during exercise?

Back

Liver, kidneys, GI tract

Answer explanation

During exercise, blood flow is prioritized to the muscles and skin for increased performance and thermoregulation. Consequently, organs like the liver, kidneys, and GI tract experience decreased blood flow.

Front

What factor influences the redistribution of blood flow during exercise?

Back

Exercise intensity

Answer explanation

Exercise intensity significantly influences blood flow redistribution during exercise, as higher intensity demands more oxygen and nutrients, directing blood to active muscles while reducing flow to less active areas.

Front

Primary change in blood flow distribution during heavy exercise compared to rest?

Back

Increased blood flow to the muscles

Answer explanation

During heavy exercise, blood flow primarily increases to the muscles to meet their heightened demand for oxygen and nutrients, while flow to other areas like the brain, kidneys, and skin is reduced.

Front

During rest, what percentage of cardiac output is directed to the kidneys?

Back

4-5%

Answer explanation

During rest, the kidneys receive about 4-5% of the total cardiac output. This percentage is crucial for maintaining kidney function and ensuring proper filtration of blood.

Front

How much cardiac output is directed to the skin during heavy exercise?

Back

15-20%

Answer explanation

During heavy exercise, the body prioritizes blood flow to essential organs and muscles, directing about 15-20% of cardiac output to the skin for thermoregulation, making this the correct choice.

Front

During exercise, how much greater is the oxygen demand by muscles compared to at rest?

Back

15-25x greater

Answer explanation

During exercise, muscles require significantly more oxygen to meet increased energy demands. The oxygen demand can be 15-25 times greater than at rest, making this the correct choice.