Exam 3

Question 1

What are the factors that have a positive influence on the increase of venous return in the short-term?

Answer 1

1. Cardiac Suction
2. Respiratory Pump
3. Skeletal Muscle Pump
4. Increase in sympathetic vasoconstriction activity
5. The driving pressure generated from cardiac contraction
6. Venous valves

Question 2

What are the factors that have a positive influence on the increase of venous return in the long-term?

Answer 2

An increase in blood volume due to salt and water retention or a passive bulk flow shift of fluid from interstitial fluid into the plasma.

Question 3

How does salt/water retention occur in the body with the result of an increase in venous return?

Answer 3

The renin-angiotensin-aldosterone system

Question 4

How is blood pooling in the veins due to gravity remidied?

Answer 4

When moving from a lying position to a standing position, the mean arterial pressure drops stimulating a sympathetic response which causes vasoconstriction of the veins driving blood towards heart. In addition, skeletal muscle contractions “milk” the veins to move blood towards heart.

Question 5

What type of cells are capillaries lined by?

Answer 5

Single layer of endothelial cells

Question 6

General anesthetics and other materials that can diffuse through lipid bilayers of endothelial cells in capillaries are called __________ .

Answer 6

Lipophilic

Question 7

What controls blood flow through the capillaries?

Answer 7

The precapillary sphincter; located at the origin..the only smooth muscle found on the capillary.