Pressure and Flow in Arteries and Veins

Question 1

What factors affect the pressure wave in elastic arteries?

Answer 1

• stoke volume
• velocity of ejection
• elasticity of arteries
• total peripheral resistance

Question 2

What is the pressure drop through arteries?

Answer 2

~ 95 to 90 mmHg

Question 3

What changes in pressure occur in arterioles?

Answer 3

~ 90 to 40 mmHg

Question 4

Describe blood pressure in the capillaries.

Answer 4

• already low when blood reaches the capillaries

- good because they are thin-walled

Question 5

What is the systemic filling pressure?

Answer 5

~ 20 to 5 mmHg

Question 6

How does pulmonary circulation and systemic circulation differ in terms of pressure?

Answer 6

• pulmonary circulation is one-fifth the pressure of the systemic circulation

Question 7

Where is blood flow the fastest and the slowest?

Answer 7

• fastest in the aorta and vena cava

- slowest in the capillaries

Question 8

What does velocity in the blood vessels depend on?

Answer 8

• the total cross-sectional area (cm^2)

Question 9

Does gravity affect driving pressure from arteries to veins?

Answer 9

No.

• but does cause venous distension in legs

Question 10

Define venomotor tone.

Answer 10

A state of contraction of the smooth muscle surrounding the venules and veins.

Question 11

What is systemic filling pressure?

Answer 11

• pressure created by ventricles and transmitted through vascular tree to the veins

Question 12

What factors affect venous pressure and hence, venous return?

Answer 12

• gravity
• skeletal muscle pump
• respiratory pump
• venomotor tone
• systemic filling pressure