Chapter 21 Muscle Blood Flow

Question 1

Describe how decreased oxygen in muscle enhances blood flow

Answer 1

When muscles are active, they use oxygen rapidly, decreasing oxygen concentration in the tissue fluids. This causes arteriolar vasodilation because they cannot stay contracted without oxygen.

Question 2

What are some factors that contribute to vasodilation during exercise?

Answer 2

1. adenosine
2. K
3. LA
4. CO2

Question 3

What are the 3 major effects during exercise that are essential for the circulatory system to supply the blood flow required by muscles?

Answer 3

1. Sympathetic nervous system activation
2. increase in arterial pressure
3. increase in cardiac output

Question 4

The left coronary artery supplies the?

Answer 4

anterior and left portions of the left ventricle

Question 5

The right coronary artery supplies the?

Answer 5

the right ventricle as well as the posterior part of the left ventricle in 80-90% of people

Question 6

How does the coronary venous blow from the left ventricular muscle to the right atrium? the right ventricular muscle?

Answer 6

the coronary sinus
small anterior cardiac veins

Question 7

Normal coronary blood flow

Answer 7

70ml/min/100g of heart weight; 225ml/min