Exam 3: Lecture 10

Question 0

What is aortic valve stenosis?

Answer 0

When the aortic valve opening is reduced and blood flow through is diminished

Question 1

What are the two major factors that affect pulse pressure and what is their equation?

Answer 1

Stroke volume output of the heart
Compliance of the arterial tree
Pulse Pressure=Stroke volume/Arterial compliance

Question 2

What does atherosclerosis cause?

Answer 2

Reduced compliance of vessel walls

Question 3

What is patent ductus arteriosus?

Answer 3

Occurs due to ductus arteriosus not closing in fetus
Half or more of cardiac output flows back into pulmonary artery and lungs causing diastolic pressure to fall very low before next heart beat

Question 4

What is aortic regurgitation?

Answer 4

Aortic valve is absent or will not close completely

Aortic pressure may fall to 0 before next heartbeat

Question 5

What is Central Venous Pressure equal to?

Answer 5

Pressure in right atrium

Question 6

What are the 2 factors that regulate right arterial pressure?

Answer 6

Ability of heart to pump blood out of right atrium/ventricle

Tendency of blood to flow into right atrium

Question 7

What are the 3 factors that increase venous return (right atrial pressure)?

Answer 7

Increased blood volume
Increased peripheral venous pressure due to increased large vessel tone
Dilation of arterioles

Question 8

T/F: When a person is lying down, pressure in peripheral veins is 4-6 mmHg greater than right atrial pressure.

Answer 8

True

Question 9

T/F: When intra-abdominal pressure increases, venous pressure in legs must decrease below abdominal pressure before blood can flow from legs to heart through abdominal veins.

Answer 9

False, venous pressure in legs must increase above abdominal pressure

Question 10

Describe arterioles

Answer 10

Highly muscular (until metarteriole)
Small ones control blood flow to each tissue
Local tissue conditions control diameters of arterioles

Question 11

Are capillaries surrounded by skeletal or smooth muscle at origination point from metarteriole?

Answer 11

Smooth (precapillary sphincter)

Question 12

Describe the capillary wall

Answer 12

Unicellular layer of endothelial cells
Thin basement membrane
0.5µm think with 4-9µm diameter

Question 13

Describe slit pores

Answer 13

Intercellular clefts

Allow for rapid diffusion of water, water-soluble ions, and small solutes

Question 14

Describe plasmalemmal vesicles

Answer 14

Formed from caveolins

Play role in endocytosis and transcytosis

Question 15

What is the most important factor regulation vasomotion?

Answer 15

[Oxygen] in tissues

Question 16

What is the most important role of diffusion between blood and interstitial fluid?

Answer 16

Exchange substances

Question 17

What type of substances can diffuse readily through the capillary cell membranes?

Answer 17

Lipid-soluble
Oxygen
CO2

Question 18

What type of substances diffuses through the pores/clefts?

Answer 18

Non-lipid-soluble substances

Question 19

T/F: The rate of water diffusion is 100x faster than flow of plasma within capillary.

Answer 19

False, 80x faster

Question 20

What do Starling forces do?

Answer 20

Determine direction of diffusion into or out of capillary

Question 21

What are the two outward Starling forces?

Answer 21

Capillary pressure = Hydrostatic pressure of blood

Interstitial fluid colloid osmotic pressure = Osmotic pressure of interstitial fluid

Question 22

What are the two inward Starling forces?

Answer 22

Interstitial fluid pressure = Hydrostatic pressure of interstitial fluid
Capillary plasma colloid osmotic pressure = Osmotic pressure of blood

Question 23

What does the sum of the 2 outward forces and 2 inward forces equal?

Answer 23

Net filtration pressure

Question 24

What does the capillary coefficient take into consideration?

Answer 24

The number and size of pores

Question 25

T/F: Lymph vessel contraction is NOT large enough force to be considered a Starling force?

Answer 25

True

Question 26

What are the 2 major descriptions of lymph return?

Answer 26

Lymph vessels have 1-way valves

Lymph flow is maximum when interstitial pressure rises above atmospheric pressure

Question 27

What are the factors that increase lymph flow (and interstitial fluid pressure)?

Answer 27

Elevated capillary hydrostatic pressure
Decreased plasma colloid osmotic pressure
Increased interstitial fluid colloid osmotic pressure
Increased permeability of capillaries