[2] Lecture 11: Arterial And Venous Systems And Lymphatics

Question 1

Term used to describe the ease asso. W/ spread of the vessel

Answer 1

Vascular distensibility

Question 2

TellsThe total quantity of blood (mL) that a be stored in a given portion of the circulation for each mm Hg rise in pressure

Answer 2

Vascular compliance

Question 3

Describes how volume changes in response to Change in pressure

Answer 3

Capacitance

Question 4

A measure of the ease w/ which a hollow viscus may be distended

I.e. The ∆V resulting from the application of a unit pressure differential btw inside and outside of viscus; reciprocal of elastance

Answer 4

Compliance

Question 5

A measure of the tendency of a hollow viscus to recoil towards its original dimensions upon removal of a distending or collapsing force

Answer 5

Elastance

Question 6

Formula for vascular distensibility

Answer 6

F= (increase in V / increase in P x Original volume)

Question 7

Which is more distensible veins or arteries?

Answer 7

Veins are 8 times more distensible.

Question 8

Pulmonary arteries vs systemic artery distensibilities:

Answer 8

Pulmonary arteries are 6 times MORE distensible than systemic arteries

Question 9

Pulmonary veins and systemic veins-distensibility

Answer 9

Same

Question 10

Vascular compliance formula:

Answer 10

Increase in V /
Increase in P

=

VD x V(orig) = compliance

Question 11

This term describes distensibility of blood vessels:

Answer 11

Capacitance

Question 12

_________ is inversely proportional to elastance

Answer 12

Capacitance [mL/ mm Hg]

Question 13

Directly proportional to volume and inversely proportional to pressure

Answer 13

Capacitance

Question 14

This is higher in veins than arteries:

And decreases in arteries with age

Answer 14

Capacitance

Question 15

The more elastic tissue:

Answer 15

Higher the elastance and lower compliance

Question 16

Total quantity of blood that can be stored in a given portion of the circulatory system.

Answer 16

Vascular compliance

Question 17

A systemic vein is 8x as distensible as it corresponding artery and have volume 3 x as great. How would its compliance compare to that of the corresponding artery?

Answer 17

24 times more

Question 18

Removing a little volume from arteries has drastic effect, however hundreds of ml can be removed from venous system w/ little change in pressure. Why?

Answer 18

Arteries are elastic and not very compliant, volume is removed= P will drop.

Because veins are VERY compliant, volume can be removed with little change in Pressure.

Question 19

Pressure-volume curves show: [veins/arteries]

Answer 19

Veins: little change in pressure w/ big ∆ in volume

Arteries: big change in pressure w/ little ∆V

Question 20

SV /

Arterial compliance =

Answer 20

Pulse pressure

Question 21

2 factors affect pulse pressure

Answer 21

SV output of the heart

Compliance of arterial tree

Question 22

Most important determinant of pulse pressure

Diastolic P remains unchanged during ventricular systole; pulse pressure increases to same extent as the systolic pressure

Answer 22

SV output of the heart

Question 23

Decreases in compliance (capacitance) i.e. Aging, result in an increase in pulse pressure

Answer 23

Compliance of the arterial tree

Question 24

What happens to pulse pressure when compliance goes down?

Answer 24

Increases

Question 25

4 conditions that cause abnormal contours of the pressure pulse wave:

Answer 25

1-aortic valve stenosis 2-atherosclerosis 3-patent ductus arteriosus 4-aortic regurgitation

Question 26

Diameter of the aortic valve opening is narrowed significantly, and the aortic pressure pulse is decreased greatly. Blood flow through aortic valve is diminished.

Answer 26

Aortic valve stenosis

Question 27

Half or more of the CO flows back into the pulmonary artery and lung blood vessels Diastolic pressure falls very low before next heartbeat

Answer 27

patent ductus arteriosus

Question 28

Aortic valve is absent or will not close completely Aortic pressure may fall all the way to 0 btw heart beats.

Answer 28

Aortic regurgitation

Question 29

A downward notch in the curve recording aortic blood pressure that occurs btw systole and diastole and is caused by backflow of blood for a short time before aortic valve closes

Answer 29

Incisura

Question 30

Why does atherosclerosis cause pulse pressure to rise above 120 mmHg ?

Answer 30

Greater afterload to pump against

Question 31

Why does aortic regurgitation lack a incisura on pressure curve?

Answer 31

The incisura is usually caused by aortic valve backflow of blood. There's essentially no aortic valve in aortic regurgitation. Like a one way pipe

Question 32

Explain why the pulse pressure drops below 80 mm Hg in patent ductus arteriosus and aortic regurgitation:

Answer 32

Half or more of CO flow back into pulmonary artery and lung. Decreasing pressure greatly.

Question 33

As pressure pulse waves progress from large vessels toward smaller vessels

Answer 33

Damping of the pressure pulses

Question 34

Sounds of blood while taking BP:

Answer 34

Korotkoff sounds are the opposing forces of the blood flow.

Question 35

Mean pressure lie closer to diastolic or systolic?

Answer 35

Diastolic: 60% of cardiac cycle is spent in diastole, 40% in systole.

Question 36

Average arterial pressure w/ respect to time

Answer 36

Mean arterial pressure

Question 37

MAP is simple average of diastolic and systolic?

Answer 37

No, more time is spent in diastole.

Question 38

FOrmula for MAP:

Answer 38

Diastole Pressure + 1/3pulse pressure = MAP

Question 39

Pressure in the R atrium

Answer 39

Central venous pressure [CVP]

Question 40

Factors that regulate CVP or R atrial pressure:

Answer 40

Ability of heart to pump blood out of R atrium/ventricle Tendency of blood to flow into R atrium

Question 41

Estimating L atrial pressure. HOw?

Answer 41

Pulmonary wedge pressure: catheter w/ almost direct contact w/ pulmonary capillaries...almost equal to L atrial pressure

Question 42

Increase venous pressure =

Answer 42

Increased R atrial pressure

Question 43

Factors that increase R atrial pressure

Answer 43

Increased blood volume Increased peripheral venous pressures d/t increased large vessel tone Dilation of arterioles

Question 44

When lying down, pressure in peripheral veins is:

Answer 44

is +4 to +6mm Hg > R atrial pressure

Question 45

When intra-and pressure increases venous pressure must:

Answer 45

Increase above the bad pressure before blood can flow from the legs to the heart through the abd veins

Question 46

Points that can collapse veins when entering thorax

Answer 46

Compression points

Question 47

When standing, effect of pressure on venous pressures

Answer 47

The further distal and inferior = the greater pressure

Question 48

BLood reservoir in circulatory system:

Answer 48

Spleen. Can introduce more blood into circulation if tissues req'

Question 49

When volume is added:

Answer 49

Compensates by decreasing tone = increasing compliance

Question 50

When volume is depleted :

Answer 50

Compensation by increasing tone = decreasing compliance

Question 51

What helps to push blood back to the heart in the veins?

Answer 51

Muscle contraction

Question 52

What is a cause of venous varicosities

Answer 52

Backflow of blood creates enough pressure to destroy valves.

Question 53

Small vessels control blood flow to each tissue Highly muscular

Answer 53

Arterioles

Question 54

What controls diameter of arterioles?

Answer 54

Local conditions in tissues

Question 55

Continuous musculature present in metarterioles?

Answer 55

No only arterioles

Question 56

Smooth muscle fiber encircles capillary at point where it originates

Answer 56

Metarteriole - also called precapillary sphincter

Question 57

Do capillaries have smooth muscle?

Answer 57

No

Question 58

Unicellular layer of endothelial cells Thin basement membrane Total wall thickness= 0.5microns Internal capillary diameter=4-9microns

Answer 58

Capillaries

Question 59

Refers to the opening and closing of precapillary sphincter

Answer 59

Vasomotion

Question 60

Occluding parts of the metarteriole to another capillary bed

Answer 60

Perferential channel

Question 61

Spacing 6-7 nm Allows for raid diffusion of water,water-soluble ions, and small solutes

Answer 61

Slit pores [in capillary]

Question 62

Formed from caveolins Plays a role in endocytosis and transcytosis

Answer 62

Plasmalemmal vesicles

Question 63

Ex; of organs w/ capillaries w/ pores

Answer 63

Liver, GI tract, kidney

Question 64

Intercellular cleft can form

Answer 64

Transport channels

Question 65

Caveolin is important for

Answer 65

Endocytosis and transcytosis

Question 66

What is the most important factor in regulation of vasomotion?

Answer 66

[oxygen] in the tissues - determines how much blood flow to feed tissues

Question 67

The most important means for the exchange of substances btw the blood and the interstitial fluid

Answer 67

Diffusion

Question 68

What 2 lipid-soluble substances can rapidly diffuse through capillary cell membranes:

Answer 68

Oxygen | Carbon dioxide

Question 69

Where do nonlipid-soluble substances diffuse through membrane?

Answer 69

Intercellular clefts/pores

Question 70

Compare rate of diffusion btw capillary membrane and flow of plasma within capillary:

Answer 70

Rate of water diffusion thru capillary membrane is 80x faster than flow of plasma w/in capillary

Question 71

Blood flow from arterial end, capillary, venous end and lymphatic can be described as:

Answer 71

Bidirectional

Question 72

Directly proportional to [ ] differences of the diffusing substance

Answer 72

Rate of diffusion

Question 73

Passage of substances through the interstitium is mostly via ____ rather than flow

Answer 73

Diffusion

Question 74

Major component of interstitium and main reason diffusion is most common way of transport in interstitium

Answer 74

Proteoglycan filaments Also, rivulets allow fluid flow through the interstitium do sometimes form

Question 75

Free fluid in interstitium

Answer 75

rivulets

Question 76

What determines direction of diffusion into or out of a capillary?

Answer 76

Starling forces

Question 77

Name the 4 starling forces:

Answer 77

Capillary pressure-outward F Interstitial fluid pressure- inward F Capillary Plasma colloid osmotic pressure-inward F Interstitial fluid colloid osmotic pressure- outward F

Question 78

Sum of starling forces=

Answer 78

Net filtration pressure [NFP]

Question 79

Name the coefficient that can be added to the NFP formula to make it more accurate:

Answer 79

Capillary filtration coefficient - takes into consideration the number and size of pores Just multiply it by NFP

Question 80

What happens When fluid enters the lymphatic?

Answer 80

The lymph vessel walls contract momentarily and pump fluid into blood circulation.

Question 81

Fluid entering lymphatic so pushes some other fluid into the bloodstream. Why?

Answer 81

Movement into lymphatic creates a slightly negative pressure in the interstial spaces.

Question 82

Forces of filtration at venous end of capillary

Answer 82

Net inward force= 7 mm Hg

Question 83

Forces of filtration at arterial end of capillary

Answer 83

Net outward force = 13 mm Hg

Question 84

Only starling force that changes during exchange from arterial to venous:

Answer 84

Capillary pressure= 30->10 from arterial end to venous end

Question 85

Lymph vessels possess _______ valves

Answer 85

1 way

Question 86

When does lymph flow reach a maximum?

Answer 86

When interstitial pressure rises slightly above atmospheric pressure

Question 87

Factors that increase lymph flow:

Answer 87

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

Question 88

Interstitial pressure x activity of lymphatic pump =

Answer 88

Rate of lymph flow

Question 89

Proteins help open interstial space of lymph capillaries:

Answer 89

Anchoring filament

Question 90

Goal for arteriolar end of capillary?

Answer 90

Move fluid from capillary to interstitium

Question 91

Goal for venous end of capillary?

Answer 91

push fluid into vein from interstitium