Circulation

Question 1

Systemic capillaries arteriolar ends

Answer 1

35mmHg

Question 2

Sc Venous ends

Answer 2

10mmHg

Question 3

Ave. Capillary pressure

Answer 3

17mmHg

Question 4

Glomerular capillaries pressure

Answer 4

60mmHg

Question 5

T/F

total blood flow through the lungs is the same as that in the systemic circulation because of the lower vascular resistance of the pulmonary blood vessels.

Answer 5

True

Question 6

Ohm’s law in blood vessel

Answer 6

F = change in pressure/resistance

Question 7

the total pulmonary vascular resistance is much higher than the systemic vascular resistance.

T/F

Answer 7

False. Lower

Question 8

Decreased Radius of a Blood Vessel Markedly Increases Vascular Resistance.

Answer 8

True

Question 9

portion slightly away from the wall has moved a small distance, and the portion in the center of the vessel has moved a long distance.

Answer 9

para-bolic profile for velocity of blood flow.”

Question 10

the blood flows crosswise in the vessel and along the vessel, usually forming whorls in the blood, called eddy currents.

Answer 10

Turbulent flow

Question 11

Turbulent flow due to

Answer 11

obstruction in a vessel,
when it makes a sharp turn, or
when it passes over a rough surface,

Question 12

measure of the tendency for turbulence to occur

Answer 12

Reynolds’ number

Question 13

turbulence will usually occur even in a straight, smooth vessel.

Answer 13

Reynolds’ number rises above approximately 2000

Question 14

Pulmonary BP

Answer 14

25/8 mmHg

Question 15

Pulmonary capillary pressure

Answer 15

16 mmHg

Question 16

Thus, the conductance of the vessel increases in proportion to the

Answer 16

fourth power of the diameter, in accordance with the following formula:

Conductance = Diameter∝4

Question 17

blood in the ring touching the wall of the vessel is barely flowing because of its adherence to the vascular endothelium

Answer 17

Poiseuille’s Law.

F →(π ∆Pr^4)/(8 η l)

Question 18

viscosity of normal blood is about 4 times as great as the viscosity of water. T/F

Answer 18

False. 3

Question 19

increase in arterial pressure not only increases the force that pushes blood through the vessels but also

Answer 19

initiates compensatory increases in vascular resistance within a few seconds through activation of the local control mechanism

Question 20

ability of each tissue to adjust its vascular resistance and to maintain normal blood flow during changes in arterial pressure between approximately 70 and 175 mm Hg

Answer 20

blood flow autoregulation.

Question 21

sympathetic  nerve stimulation  or  vasoconstriction  by  hormones  such  as

Answer 21

norepineph rine,  angiotensin  II,  vasopressin,  or  endothelin

Question 22

Vascular distensibility Increase in volume/(Increase in pres × ssure Original volume)

Answer 22

fractional increase in volume for each millimeter of mercury rise in pressure

Question 23

total quantity of blood that can be stored in a given portion of the circulation for each mm Hg pressure rise

Answer 23

compliance or capacitance

Vascular compliance=(Increase in volume / Increase in pressure)

Question 24

the volume of blood injected causes immediate elastic distention of the vein, but then the smooth muscle fibers of the vein begin to “creep” to longer lengths, and their tensions correspondingly decrease.

Answer 24

stress-relaxation or Delayed compliance

Question 25

T he difference between these two pressures, about 40 mm Hg

Answer 25

pulse pressure.

Question 26

diameter of the aortic valve opening is reduced significantly, and the aortic pressure pulse is decreased significantly because of diminished blood flow outward

Answer 26

aortic valve stenosis

Question 27

one half or more of the blood pumped into the aorta by the left ventricle flows immediately backward allowing the diastolic pressure to fall very low before the next heartbeat.

Answer 27

patent ductus arteriosus

Question 28

after each heartbeat, the blood that has just been pumped into the aorta flows immediately backward As a result, the aortic pressure can fall all the way to zero between heartbeats

Answer 28

aortic regurgitation

Question 29

there is an incisura in the aortic pulse contour because there is no aortic valve to close. T/F

Answer 29

False. None

Question 30

velocity of pressure pulse transmission in the aorta

Answer 30

3-5 m/sec

Question 31

velocity of pressure pulse transmission in the large arterial branches,

Answer 31

7 to 10 m/sec

Question 32

velocity of pressure pulse transmission in the small arteries

Answer 32

15 to 35 m/sec

Question 33

the greater the compliance of each vascular segment, the slower the velocity, which explains

Answer 33

the slow transmission in the aorta and the much faster transmission in the much less compliant small distal arteries

Question 34

cause of damping is twofold: (1) resistance to blood movement in the vessels, and 2) compliance of the vessels. Why?

Answer 34

resistance damps the pulsations because a small amount of blood must flow forward at the pulse wave front to distend the next segment compliance damps the pulsations because the more compliant a vessel, the greater the quantity of blood required at the pulse wave

Question 35

primarily responsible for this long-term regulation of arterial pressure; exhibit definitive changes with age, especially after the age of 50 years.

Answer 35

kidneys

Question 36

The mean arterial pressure is therefore determined about

Answer 36

60 percent by the diastolic pressure and 40 percent by the systolic pressure.

Question 37

pressure in the right atrium is called the

Answer 37

central venous pressure

Question 38

factors that can increase this venous return and thereby increase the right atrial pressure are

Answer 38

1) increased blood volume 2) increased large vessel tone 3) dilation of the arterioles, which decreases the peripheral resistance

Question 39

normal right atrial pressure

Answer 39

0 mm Hg,

Question 40

normal right atrial pressure can increase to 20 to 30 mm Hg under very abnormal conditions, such as

Answer 40

1) serious heart failure or (2) after massive transfusion of blood

Question 41

lower limit to the right atrial pressure

Answer 41

usually about −3 to −5 mm Hg below atmospheric pressure,

Question 42

thus the pressure in the more peripheral small veins in a person lying down is usually

Answer 42

+4 to +6 mm Hg greater than the right atrial pressure.

Question 43

What happens when When the right atrial pressure rises above its normal value of 0 mm Hg,

Answer 43

blood begins to back up in the large veins.

Question 44

pressure in the abdominal cavity of a recumbent person normally averages about +6 mm Hg, but it can rise to +15 to +30 mm Hg as a result of

Answer 44

pregnancy, large tumors, abdominal obesity, or excessive fluid

Question 45

in an adult who is standing absolutely still, the pressure in the veins of the feet is about

Answer 45

+90 mm Hg simply because of the gravitational weight of the blood in the veins between the heart and the feet

Question 46

In the arm veins, the pressure at the level of the top rib is usually about

Answer 46

+6 mm Hg

Question 47

+35 mm Hg pressure in the veins of the hand. Y?

Answer 47

gravitational difference between the level of the rib and the hand is +29 mm Hg, this gravitational pressure is added to the +6 mm Hg pressure caused by compression of the vein

Question 48

negative pressure can exist in the dural sinuses of the head t/f

Answer 48

True

Question 49

if the sagittal sinus is opened during surgery,

Answer 49

air can be sucked immediately into the venous system; the air may even pass downward to cause air embolism

Question 50

it is efficient enough that under ordinary circumstances the venous pressure in the feet of a walking adult remains less than +20 mm Hg.

Answer 50

venous pump” or “muscle pump,

Question 51

reservoirs and the volume they provide 100 milliliters several hundred milliliters as much as 300 milliliters 50 to 100 mil-liliters of blood; another 100 to 200 milliliters when the pulmonary pressures decrease to low values.

Answer 51

spleen, As much as 50 milliliters of concentrated red blood cells can be released into the circulation, raising the hematocrit 1 to 2 percent. liver, the sinuses of which can release several hundred milliliters of blood into the remainder of the circulation; the large abdominal veins, venous plexus beneath the skin, which also can contribute several hundred milliliters. heart and the lungs, although not parts of the systemic venous reservoir system

Question 52

peripheral circulation of the entire body has about

Answer 52

500 to 700 square meters

Question 53

generally have internal diameters of only 10 to 15 micrometers

Answer 53

arterioles

Question 54

total thickness of the capillary wall is only about

Answer 54

0.5 micrometer

Question 55

The internal diameter of the capillary is — barely large enough for red blood cells and other blood cells to squeeze through.

Answer 55

4 to 9 micrometers,

Question 56

most important factor affecting the degree of opening and closing of the metarterioles and precapillary sphincters that has been found thus far

Answer 56

is the concentration of oxygen in the tissues.

Question 57

results from thermal motion of the water molecules and dissolved substances in the fluid,

Answer 57

Diffusion

Question 58

lipid-insoluble substances that can go only through the pores.

Answer 58

sodium ions and glucose Water Cl

Question 59

the rate at which water molecules diffuse through the capillary membrane is about 80 times as great as the rate at which plasma itself flows linearly along the capillary

Answer 59

True

Question 60

width of the capillary intercellular cleft-pores,

Answer 60

Pores. The width of the capillary intercellular cleft-pores, 6 to 7 nanometers, is about 20 times the diameter of the water molecule

Question 61

The capillaries in various tissues have extreme differences in their permeabilities

Answer 61

True

Question 62

proportional to the concentration difference of the substance b

Answer 62

net” rate of diffusion concentration of oxygen in capillary blood is normally greater than in the interstitial fluid

Question 63

Determine Fluid Movement Through the Capillary Membrane.

Answer 63

Hydrostatic and Colloid Osmotic Forces

Question 64

force f luid outward through the capillary membrane. tends to cause osmosis of fluid outward through the capillary membrane.

Answer 64

capillary pressure interstitial fluid colloid osmotic pressure

Question 65

force fluid inward through the capillary membrane cause osmosis of fluid inward through the capillary membrane.

Answer 65

interstitial fluid pressure interstitial fluid pressure capillary plasma colloid osmotic pressure

Question 66

If the sum of the Starling forces is postive, there will be a net fluid absorption from the interstitial spaces into the capillaries. T/F

Answer 66

False. Negative

Question 67

direct micropipette cannulation of the capillaries, which has given an average mean capillary pressure of

Answer 67

about 25 mm Hg in some tissues such as the skeletal muscle and the gut,

Question 68

has given a capillary pressure averaging about 17 mm Hg in these tissues.

Answer 68

indirect functional measurement of the capillary pressure,

Question 69

the “functional” capillary pressure in this tissue is measured to be about 17 mm Hg.

Answer 69

Isogravimetric Method for Indirectly Mea suring “Functional” Capillary Pressure

Question 70

The colloid osmotic pressure of normal human plasma averages about 28 mm Hg 19 mm of this pressure is caused by molecular effects of the dissolved protein and 9 mm is caused by the

Answer 70

Donnan effect

Question 71

extra osmotic pressure caused by sodium, potassium, and the other cations held in the plasma by the proteins.

Answer 71

Donnan effect

Question 72

the pressures in the arterial and venous capillaries are averaged to calculate mean functional capillary pressure for the entire length of the capillary. This mean functional capillary pressure calcu-lates to be

Answer 72

17.3 mm Hg.

Question 73

fluid that must be returned to the circulation through the lymphatics.

Answer 73

net filtration, The normal rate of net filtration in the entire body, not including the kidneys, is only about 2 ml/min

Question 74

whole body capillary filtration coefficient.

Answer 74

net filtration rate of 6.67 ml/min of fluid per mm Hg for the entire body

Question 75

any factor that increases interstitial fluid pressure also increases lymph flow

Answer 75

Decreased plasma colloid osmotic pressure Elevated capillary hydrostatic pressure. interstitial fluid colloid osmotic pressure,, permeability of the capillaries

Question 76

any external factor that intermittently compresses the lymph vessel also can cause pumping.

Answer 76

Contraction of surrounding skeletal muscles • Movement of the parts of the body • Pulsations of arteries adjacent to the lymphatics • Compression of the tissues by objects outside the body

Question 77

two primary factors that determine lymph flow are

Answer 77

the interstitial fluid pressure and (2) the activity of the lymphatic pump

Question 78

When the tissues lose their negative pressure, fluid accumulates in the spaces and the condition known as

Answer 78

edema occurs.