Exam 3: Atrerial Venous Lymphatic systems Presentations

Question 0

What are two factors that affect pulse pressure?

Answer 0

1. Stroke volume output of the heart 2. Compliance of the arterial tree

Question 1

Pulse pressure =

Answer 1

stroke volume/arterial compliance

Question 2

what are conditions that cause abnormal contours of the pressure pulse wave?

Answer 2

-Aortic valve stenosis *diameter of the aortic valve opening is reduced significantly, and the aortic pressure is decreased significantly. *blood flow through the aortic valve is diminished - atherosclerosis. -Patent ductus arteriosus -Aortic regulation

Question 3

What is patent ductus arteriosus?

Answer 3

• Half or more of the cardiac output flows back into the pulmonary artery and lung blood vessels. - diastolic pressure falls very low before next heartbeat.

Question 4

What is Aortic regurgitation?

Answer 4

• the aortic valve is absent or will not close completely - Aortic pressure may fall all the way to 0 between heartbeats.

Question 5

t/f is compliance is low, vessels are less able to expand

Answer 5

true

Question 6

Why does mean pressure lie closer to diastolic than systolic?

Answer 6

Because about 60% of the cardiac cycle is spent in diastole and 40% in systole.

Question 7

What are factors that regulate right atrial pressure?

Answer 7

• ability of the heart to pump blood out of the right atrium/ventricle -tendency of blood to flow into the right atrium

Question 8

What can pressure in the right atrium be related to?

Answer 8

Central venous presure

Question 9

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

Answer 9

-increased blood volume -increased peripheral venous pressures due to increased large vessel tone -Dilation of arterioles

Question 10

When do large veins offer resistance?

Answer 10

• In a person lying down the pressure in peripheral veins is +4 to +6 mmHg greater than the right atrial pressure - When intra-abdominal pressure increases, the venous pressure in the legs must increase above the abdominal pressure before blood can flow from the legs to the heart through the abdominal veins.

Question 11

List the characteristics of arterioles:

Answer 11

-small arterioles control blood flow to each tissue -local conditions in tissue control diameters of arterioles. -arterioles are highly muscular —continuous muscular coat is lost in metarterioles.

Question 12

Characteristics of capillaries:

Answer 12

-Smooth muscle fiber encircles capillary at point where it originates from a metarteriole (precapillary sphincter) -Capillary wall: has a unicellular layer of endothelial cells, thin basement membrane -total wall thickness = 0.5 micrometers -internal capillary diameter

Question 13

Define slit pores in capillaries:

Answer 13

(intercellular clefts); spacing of 6-7nm -allow for rapid diffusion of water, water soluble ions, and small solutes

Question 14

Define plasmalemmal vesicles of capillaries

Answer 14

-formed from caveolins -play a role in endocytosis and transcytosis

Question 15

List some organs that have capillaries with pores

Answer 15

liver, GI tract, kidneys

Question 16

What is the most important factor regulating vasomotion?

Answer 16

concentration of oxygen in the tissues.

Question 17

t/f osmosis is the most important means for the exchange of substances between the blood and the interstitial fluid.

Answer 17

False, diffusion is the most important

Question 18

_________ substances can diffuse readily through the capillary cell membranes.

Answer 18

Lipid-soluble, they include oxygen and carbon dioxide

Question 19

____________ substances diffuse through the intercellular pores/clefts.

Answer 19

non-lipid-soluble

Question 20

Rate of water diffusion through the capillary membrane is ______ faster than the flow of plasma within the capillary

Answer 20

80x

Question 21

The rate of diffusion is ___________ proportional to concentration differences of the diffusing substance

Answer 21

directly

Question 22

What is the passage of substance through the interstitium mostly via diffusion rather than flow?

Answer 22

• because of the large numbers of proteoglycan filaments found in the intersitium -rivulets that allow flow through the interstitium do sometimes form.

Question 23

What determines the net filtration pressure when using the startling forces?

Answer 23

sum of: - capillary pressure (outward force) -interstitial fluid pressure ( inward force) - capillary plasma colloid osmotic pressure (inward force) - Interstitial fluid colloid osmotic pressure (outward force)

Question 24

What do startling forces determine?

Answer 24

direction of diffusion into or out of a capillary

Question 25

capillary filtration coefficient

Answer 25

takes into consideration the number and size of pores filtration = Kf x NFP

Question 26

What happens when fluid enters the lymphatics

Answer 26

the lymph vessel walls contract momentarily and pump fluid in to the blood circulation. this creates a slight ( -) pressure in the interstitial spaces.

Question 27

Filtration at arterial end of capillary has a total outward force of______?

Answer 27

41mmHg capillary pressure (30 mmHg) negative interstitial free fluid pressure (3 mmHg) interstitial fluid colloid osmotic pressure (8mmHg)

Question 28

Filtration at arterial end of capillary has a force of fluid moving inward with a total pressure of ________.

Answer 28

28 mmHg plasmid colloid osmotic pressure 29 mmHg

Question 30

What is the net outward pressure in filtration at arterial end of capillary?

Answer 30

13 mmHg

Question 31

For filtration at he venous end of capillary, what is the total inward force?

Answer 31

Plasma colloid osmotic pressure 28 mmHg

Question 32

The outward force for filtration at venous end of capillary is ?

Answer 32

21 mmHg

Question 33

Accounting for the net inward and net outward forces for filtration at the venous end of capillary, the total net inward force is?

Answer 33

7 mmHg

Question 34

The lymph vessels possess 1-way valves and the lymph flow reaches maximum when interstitial pressures rise slightly above atmospheric pressure. What factors can also increase lymph flow? give 4 examples

Answer 34

• Elevated capillary hydrostatic pressure
• decreased plasma collid osmotic pressure
• increased interstitial fluid colloid osmotic pressure
• increase permeability of capillaries

The rate of lymph flow = interstitial fluid pressure x activity of lymphatic pump