1. Blood distribution varies significantly with activity. How do you think the d

Question

1. Blood distribution varies significantly with activity. How do you think the distribution will differ between eating a meal and during exercise?

–How might this relate to why you get indigestion when exercising soon after you eat?

• What mechanisms can be used to redistribute blood ?

2. Many athletes experience light-headedness when they stop immediately following vigorous exercise. Why do you think this is?

–Where is blood distributed during exercise, why/how?

To prevent this, a “cool down” period is recommended.

•Why do you think this helps?

3. Protein malnutrition is associated with fluid accumulation (edema) in tissues. Why is this?

Explanation / Answer

1)

At rest, 25% and 20% of blood is supplied to digestive system and skeletal muscle, respectively. When we eat a greater proportion of blood is directed to digestive system to supply sufficient oxygen and nutrients required for muscles and glands to carry out digestion and for absorption of nutrients.

During exercise, 70% of blood is supplied to skeletal muscles to supply nutrients and oxygen, and to remove CO2 and wastes.

If we do exercise immediately after meals causes redistribution of myocardial blood flow. This depletes blood flow to digestive tract and increases blood flow to skeletal muscle resulting in slow down of digestion. As soon as vigorous exercise is stopped, normal blood flow is restored.

2)

Running requires increased activity of skeletal muscle. In addition, increased activity of skeletal muscle generates heat. To cater to oxygen and nutrient needs of skeletal muscle, heart diverted blood to skeletal muscle. Even heart rate increases to pump more blood. This results in vasodilatation which will help in heat dissipation. After stopping the run, heart rate reduces to normal levels rapidly decreasing blood circulation, but blood vessels remain dilated. This results in fall in blood pressure and the person feels light headedness.

Cool down period is a period in which the person after exercise slows down gradually before stopping to allow metabolism to progress to resting levels. This prevents pooling blood in dilated veins in skeletal muscle. Therefore, light-headedness is not felt following exercise.

3)

Protein malnutrition causes low levels of blood protein. Proteins in blood help to hold salt and water inside the blood vessels. Lack of protein leads to fluid leak into the tissues causing edema.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.