Lecture 11: Arterial venous lymphatic systems

Question 1

Vascular distensibility equation

Answer 1

VD= Increase in volume/ Increase in pressure X original volume

Question 2

Vascular distensibility in arteries vs veins

Answer 2

Veins are 8x more distensible than arteries
Pulmonary vein distensibility is same as systemic veins
Pulmonary arteries are 6x more distensible than systemic arteries

Question 3

Vascular compliance equations

Answer 3

VC= Increase in volume/Increase in pressure
VC= VD x Original volume

Question 4

Capacitance describes the

Answer 4

Distensibility of blood vessels - how volume changes in response to a change in pressure

Question 5

Capacitance is directly proportional to _______ and indirectly proportional to ______

Answer 5

Directly proportional to volume, indirectly proportional to pressure

Question 6

Capacitance is much greater for ______ than for ______

Answer 6

Greater for veins than for arteries

Question 7

The greater the amount of elastic tissue in a blood vessel…

Answer 7

The higher the elastance

The lower the compliance

Question 8

Vascular compliance is the

Answer 8

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

Question 9

Pulse pressure equation

Answer 9

PP= Stroke volume/arterial compliance

Question 10

Factors affecting pulse pressure

Answer 10

Stroke volume output of the heart (most important factor)

Compliance of the arterial tree

Question 11

Conditions causing abnormal contours of the pressure pulse wave

Answer 11

Aortic valve stenosis
Arteriosclerosis
Patent ductus arteriosus
Aortic regurgitation

Question 12

Aortic valve stenosis

Answer 12

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

Question 13

Patent ductus arteriosus

Answer 13

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 14

Aortic regurgitation

Answer 14

The aortic valve is absent or will not close completely

Aortic pressure may fall all the way to 0 b/w heartbeats

Question 15

The progressive reduction of the pulsations in the periphery=

Answer 15

Damping of the pressure pulses

Question 16

Mean arterial pressure equation

Answer 16

MAP= Diastolic pressure + 1/3 pulse pressure

Question 17

Central venous pressure equals

Answer 17

Pressure in the right atrium

Question 18

Factors that regulate right atrial pressure

Answer 18

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

Question 19

Factors that increase venous return/right atrial pressure

Answer 19

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

Question 20

Arterioles

Answer 20

Small arterioles control blood flow to each tissue
Local conditions in tissue control diameters of arterioles
Arterioles are highly muscular

Question 21

Capillaries

Answer 21

Smooth muscle fiber encircles capillary at point where it originates from a metarteriole (referred to as a precapillary sphincter)

Question 22

Capillary wall

Answer 22

Unicellular layer of endothelial cells
Thin basement membrane
0.5um thick
Internal capillary diameter 4-9um

Question 23

Vasomotion

Answer 23

Cyclical opening and closing of precapillary sphincters

Question 24

Slit pores

Answer 24

Capillaries
Intercellular clefts- spacing of 6-7nm
Allow for rapid diffusion of water, water-soluble ions and small solutes

Question 25

Plasmalemmal vesicles

Answer 25

In capillaries
Formed from caveolins
Play a role in endocytosis and transcytosis

Question 26

Some capillaries in these organs have pores

Answer 26

Liver, GI tract, kidneys

Question 27

Most important factor regulating vasomotion

Answer 27

Concentration of oxygen in the tissues

Question 28

These lipid soluble substances can diffuse readily through the capillary cell membranes

Answer 28

Oxygen
Carbon dioxide
Non lipid soluble diffuse through pores/clefts

Question 29

Rate of water diffusion through capillary is __x faster than flow of plasma within capillary

Answer 29

80x faster

Question 30

Passage of substances through interstitium is mostly through ________ rather than ________

Answer 30

Through diffusion rather than flow

-This is due to large number of proteoglycan filaments in interstitium

Question 31

Rivulets

Answer 31

Occasionally form in interstitium and allow fluid flow

Question 32

Starling forces determine

Answer 32

Direction of diffusion into or out of a capillary

Question 33

Four types of starling forces

Answer 33

Capillary pressure (outward force)
Interstitial fluid pressure (inward force)
Capillary plasma colloid osmotic pressure (inward force)
Interstitial fluid colloid osmotic pressure (outward force)

Question 34

Net filtration pressure

Answer 34

Sum of all four starling forces

Question 35

Capillary filtration coefficient

Answer 35

Takes into consideration the number and size of pores

Filtration= NFP x Kf (Kf=Capillary filtration coefficient)

Question 36

Lymph flow reaches maximum when

Answer 36

Interstitial pressure rises slightly above atmospheric pressure

Question 37

Factors that increase lymph flow (and also interstitial fluid pressure)

Answer 37

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

Question 38

Rate of lymph flow =

Answer 38

Interstitial fluid pressure X activity of lymphatic pump