Practice Q Test 1

Question 1

Which organ in the body always receives the most blood flow?

Answer 1

the lungs always receive more blood flow than any other organ because
100% of the cardiac output passes through the lungs.

Question 2

Whenever blood flow to one organ increases, blood flow to other organs must
decrease. True or false?

Answer 2

False

Flow through any vascular bed depends on its resistance to flow
and the arterial pressure.

Question 3

The pressure in the aorta is normally about 100 mm Hg, whereas that in the pulmonary artery is normally about 15 mm Hg. A few of your fellow students offer the
following alternative hypotheses about why pulmonary artery pressure is less:

a. The right heart pumps less blood than the left heart.

b. The right heart rate is slower than the left heart rate.

c. The right ventricle is less muscular than the left ventricle.

d. The pulmonary vascular bed has less resistance than the systemic bed.

e. The stroke volume of the right heart is less than that of the left heart.

Answer 3

D

Question 4

What direct cardiovascular effects would you expect from an intravenous injection
of a drug that stimulates α-adrenergic receptors but not β-adrenergic receptors?

Answer 4

increased heart
rate, increased forcefulness of cardiac contraction, arteriolar constriction,
and venous constriction.

Question 5

Individuals with high arterial blood pressure (hypertension) are often treated with
drugs that block β-adrenergic receptors. What is a rationale for such treatment?

Answer 5

No direct effects on the heart would be expected because the sympathetic
effects on the heart are mediated by beta-receptors

Among other effects, B-adrenergic receptor blockade tends to reduce heart
rate and the forcefulness of ventricular contraction. Both these results
tend to decrease cardiac output.

Question 6

You need to determine the correct dose of an IV drug that distributes only within
the extracellular space. Which of the following values would be the closest estimate of the extracellular fluid volume of a healthy young adult male weighing 100
kg (220 lb)?
a. 3 L
b. 5 L
c. 8 L
d. 10 L
e. 20 L

Answer 6

20 L. Extracellular volume is interstitial volume plus plasma volume.
As indicated in Figure 1–1, this amounts to approximately 15 L in a
“standard person” weighing 70 kg (154 lb). !e rule of thumb is that
body weight is approximately 60% water with the intracellular volume
at approximately 40% of body weight and the extracellular volume at
approximately 20% of body weight. thus, a 100-kg person would be
expected to have approximately 20 L of extracellular fluid.

Question 7

An increase in which of the following (with the others held constant) will result in
an increase in the amount of active shortening of a cardiac muscle cell?
a. Preload
b. Afterload
c. Contractility

Answer 7

answers are a and c. Increase in preload increases the amount
of shortening by increasing the starting length of the muscle, whereas
increase in contractility increases the amount of shortening from a given
starting length. Increase in afterload limits the amount of shortening
because of increase in tension requirement.

Question 8

If pulmonary artery pressure is 24/8 mm Hg (systolic/diastolic), what are the
respective systolic and diastolic pressures of the right ventricle?

Answer 8

the ventricular systolic pressure is also 24 mm Hg because the normal
pulmonic valve provides negligible resistance to flow during ejection. the
right ventricular diastolic pressure, however, cannot be determined from
the pulmonary artery pressure. It is determined by systemic venous pressure and normally will be close to 0 mm Hg.

Question 9

Which of the following interventions will increase cardiac stroke volume?

a. Increased ventricular filling pressure
b. Decreased arterial pressure
c. Increased activity of cardiac sympathetic nerves
d. Increased circulating catecholamine levels

Answer 9

All

Question 10

In which direction will cardiac output change if central venous pressure is lowered
while cardiac sympathetic tone is increased?

Answer 10

A complete set of ventricular function curves and quantitative information about the changes in filling pressure and sympathetic tone would be necessary to answer the question

Question 11

Increases in sympathetic neural activity to the heart will result in an increase in
stroke volume by causing a decrease in end-systolic volume for any given end diastolic volume. True or false?

Answer 11

True

Question 12

With all other factors equal, myocardial oxygen demands will be increased to the
greatest extent by which of the following?

a. Increases in the heart rate
b. Increases in coronary flow
c. Increases in end-diastolic volume
d. Decreases in arterial pressure
e. Decreases in cardiac contractility

Answer 12

A

Note, increases in end-diastolic volume (choice c) will also increase
myocardial oxygen demands but to a lesser extent

Question 13

An increase in total peripheral resistance (TPR) normally results in an increase in
the external work rate required by the heart. True or false?

Answer 13

False. Recall that changes in TPR are caused by peripheral vascular
responses and that the heart normally responds by adjustments in its cardiac output to keep arterial pressure constant. At constant arterial pressure, an increase in TPR implies a reduction in CO.

Question 14

The metabolic requirement of the heart muscle in any situation is always equal to
how much external work the heart is doing in that situation. True or false?

Answer 14

False. Whereas basic thermodynamics says that to produce any given amount of external work, the heart must expend at least an equal amount
of chemical energy. But the heart muscle is only about 30% efficient in
converting chemical energy into mechanical work. thus for openers, to
produce any given external work, the heart consumes roughly 3 times
that amount of chemical energy.

metabolic requirements depend on how a given CO is accomplished.

Question 15

Describe the primary pressure abnormalities across the cardiac valve that are
associated with
a. aortic stenosis.
b. mitral stenosis.

Answer 15

a. Aortic stenosis produces a significant pressure difference between the
left ventricle and the aorta during systolic ejection (a time when this
valve normally should be widely open and create little resistance to flow).

b. Mitral stenosis produces a significant pressure difference between the
left atrium and the left ventricle during diastole (a time when this valve
normally should be widely open).

Question 16

Given the following data, name the abnormal valve, predict the type of murmur
that might be detected, and determine whether pulmonary congestion might be
present. Calculate the resistance to flow across this valve.

Aortic pressures (systolic/diastolic) = 150/100 mm Hg
Left ventricular pressures (systolic/diastolic) = 150/2 mm Hg
Left atrial pressures (systolic/diastolic) = 50/32 mm Hg
Heart rate = 60 beats/min
Stroke volume = 50 mL/beat

Answer 16

Given the abnormal pressure gradient (30 mm Hg) across the mitral valve
during diastole, we conclude it is stenotic. THis would be associated with
a diastolic murmur and, because of the elevated left atrial and pulmonary
venous pressure, could be associated with shortness of breath and/or pulmonary congestion.

Question 17

A 75-year-old male patient is alert with complaints of general fatigue. His heart
rate = 90 beats/min and arterial pressure = 180/50 mm Hg. A diastolic murmur is
present. There are no ECG abnormalities identified and mean electrical axis = 10
degrees. Cardiac catheterization indicates that LV pressure = 180/20 mm Hg and
left atrial pressure = 10/3 mm Hg (as peak systolic/end-diastolic). What abnormality is most consistent with these findings?

Answer 17

Aortic insufficiency

Question 18

Determine the direction of transcapillary fluid movement (F) within a tissue, given
the following data:
capillary hydrostatic pressure, Pc = 28 mm Hg
plasma oncotic pressure, πc = 24 mm Hg
tissue hydrostatic pressure, Pi
= −4 mm Hg
tissue oncotic pressure, πi
= 0 mm Hg

Answer 18

Filtration (movement out of the capillaries)

(28+4-24)= +8

Question 19

Which of the following conditions favor edema formation?
a. Lymphatic blockage
b. Thrombophlebitis (venous clot)
c. Decreased plasma protein concentration
d. Greatly increased capillary pore size

Answer 19

All

Question 20

Given the following data, calculate an individual’s total peripheral resistance
(TPR):
Mean arterial pressure, P 100 mm Hg A =
Central venous pressure, PCV = 0 mm Hg
Cardiac output, = 6 L/min

Answer 20

16.7mmHg/L/min

Question 21

TPR is always greater than the resistance to flow through any of the systemic
organs. True or false?

Answer 21

False. TPR is less than the resistance to flow through any of the organs.
Each organ, in effect, provides an additional pathway through which
blood may flow. thus, the individual organ resistances must be greater
than the total resistance

Question 22

Constriction of arterioles in an organ promotes reabsorption of interstitial fluid
from that organ. True or false?

Answer 22

True. Because arteriolar constriction tends to reduce the hydrostatic pressure in the capillaries, reabsorptive forces will exceed filtration forces, and
net reabsorption of interstitial fluid into the vascular bed will occur.

Question 23

Chronic elevation of arterial pressure requires that either cardiac output or TPR (or
both) be chronically elevated. True or false?

Answer 23

True

Question 24

Whenever cardiac output is increased, mean arterial pressure must also be
increased. True or false?

Answer 24

False. Increases in cardiac output are often accompanied by decreases in
total peripheral resistance.

Question 25

Acute rapid increases in arterial pulse pressure usually result from increases in stroke volume. True or false?

Answer 25

True Acute rapid changes in arterial compliance usually do not occur

Question 26

At rest, the patient has a pulse rate of 70 beats/min and an arterial blood pressure of 119/80 mm Hg. During exercise on a treadmill, pulse rate is 140 beats/min and blood pressure is 135/90 mm Hg. Use this information to estimate the exercise-related changes in the following variables: stroke volume cardiac output total peripheral resistance (TPR)

Answer 26

SV: increased by a factor of 1.15 (from 39 to 45 mm Hg) during exercise. CO: HR increased by a factor of 2 (from 70 to 140 beats/min) during exercise, and because SV increased by a factor of about 1.15, cardiac output must have increased by approximately 130%. [2.0 (1.15) = 2.3 times the original level. TPR:increased by a factor of 1.13 (from 93 to 105 mm Hg) during exercise, whereas CO increased by approximately 2.3 times. !us, total peripheral resistance must have decreased by approximately 55% (1.13/2.3 = 0.45 of the original level).

Question 27

Which of the following is consistent with a normal mean arterial pressure but an abnormally high arterial pulse pressure? a. Low stroke volume b. High heart rate c. Decreased total peripheral resistance d. Increased arterial stiffness e. Aortic valve stenosis

Answer 27

D

Question 28

Autoregulation of blood flow implies that arterial pressure is adjusted by local mechanisms to ensure constant flow through an organ. True or false?

Answer 28

False. Autoregulation of blood flow implies that vascular resistance is adjusted to maintain constant flow in spite of changes in arterial pressure.

Question 29

Arteriolar constriction tends to do which of the following? a. Decrease total peripheral resistance b. Decrease mean arterial pressure c. Decrease capillary hydrostatic pressure d. Increase transcapillary fluid filtration e. Increase blood flow through the capillary bed

Answer 29

C

Question 30

Coronary blood flow occurs mostly during diastole. True or false?

Answer 30

True. During systole, coronary vessels are collapsed by external compression forces.

Question 31

Which of the following will decrease the mean circulatory filling pressure? a. Increased circulating blood volume b. Decreased arteriolar tone c. Increased venous tone

Answer 31

None of the choices are correct A and C INCREASE PSF B doesnt have effect on PSF

Question 32

In a steady state, venous return will be greater than cardiac output when a. peripheral venous pressure is higher than normal. b. blood volume is higher than normal. c. cardiac sympathetic nerve activity is lower than normal.

Answer 32

None. Venous return must always equal cardiac output in the steady-state situation

Question 33

In a severely dehydrated patient, you might expect to find a. a depressed cardiac function curve. b. an increased mean circulatory filling pressure. c. an increased central venous pressure. d. distended jugular veins. e. decreased cardiac output.

Answer 33

E

Question 34

If you gave a blood transfusion to a patient who had recently experienced a severe hemorrhage, you would expect a. to expand arterial volume. b. To expand venous volume. c. to decrease central venous pressure. d. to decrease the mean circulatory filling pressure. e. to reduce cardiac output.

Answer 34

B

Question 35

Which of the following would directly (by themselves in the absence of any compensatory responses) tend to decrease central venous (cardiac filling) pressure? a. Increased sympathetic nerve activity to only the heart b. Increased parasympathetic nerve activity to only the heart c. Increased blood volume d. Decreased total peripheral resistance e. Immersion in water up to the waist

Answer 35

A

Question 36

Your patient has lower-than-normal mean arterial pressure and higher-thannormal pulse rate. Which of the following are possible diagnoses? a. Low blood volume b. Anxiety c. A cardiac valve problem d. Elevated intracranial pressure

Answer 36

A and C

Question 37

In general, normal kidneys tend to retain sodium and fluid in the body whenever a. arterial pressure is high. b. parasympathetic nerve activity is high. c. sympathetic nerve activity is high. d. plasma aldosterone levels are low. e. plasma renin levels are low.

Answer 37

C

Question 38

If your patient’s mean systemic arterial pressure changes, it must be because of changes in a. the heart rate and/or myocardial contractility. b. cardiac output and/or total peripheral resistance. c. blood volume and/or venous tone. d. sympathetic and/or parasympathetic nerve activity. e. arterial compliance and/or stroke volume.

Answer 38

B

Question 39

How are the thin-walled capillaries in the feet able to withstand pressures greater than 100 mm Hg in a standing individual without rupturing?

Answer 39

Because capillaries have such a small radius, the tension in the capillary wall is rather modest despite very high internal pressures.

Question 40

The “iron lung,” used to help polio victims breathe in the mid-20th century, applied an external intermittent negative pressure to the patient’s thoracic cavity. How might this be better than positive-pressure artificial ventilation of the patient’s lungs?

Answer 40

the external negative pressure served to expand the thorax and “pull” air into the lungs through the patient’s airways in much the same way that the thoracic muscle and diaphragm expand the thorax in normal breathing. !is method of ventilating the lungs did not have the adverse cardiovascular consequences that positive-pressure artificial ventilation has.

Question 41

Phenylephrine is a drug that specifically stimulates cardiovascular α-adrenergic receptors. If you gave phenylephrine to a patient, what would you expect would happen to sympathetic nerve activity, to myocardial contractility, to total peripheral resistance, and to heart rate?

Answer 41

the primary disturbance of phenylephrine will be to increase total peripheral resistance. The resulting increase in arterial blood pressure and increased firing of the arterial baroreceptors will cause a compensatory reflex decrease in sympathetic nerve activity (and increase in parasympathetic activity), which will reflexly decrease both myocardial contractility and heart rate.

Question 42

Your 70-year-old 70-kg patient has an ejection fraction of 67% at rest. Left ventricular end-diastolic volume is 210 mL. Which of the following statements best fits these data? a. These are normal data for someone this age. b. Your patient may be a competitive polka dancer. c. Your patient may be su!ering from chronic systolic heart failure. d. Your patient may be severely hypovolemic. e. Stroke volume is ∼70 mL

Answer 42

C (higher SV for trained athletes)

Question 43

All of the following tend to occur when a person lies down. Which one is the primary disturbance that causes all the others to happen? a. The heart rate will decrease. b. Cardiac contractility will increase. c. Sympathetic activity will decrease. d. Parasympathetic activity will increase. e. Central venous pressure will increase

Answer 43

E

Question 44

Aortic stiffness may increase substantially with old age. What is/are the expected consequences of this change? a. An increase in total peripheral resistance b. An increase in stroke volume c. An increase in pulse pressure d. An increase in mean arterial pressure

Answer 44

C: stiff arteries associated with increase pressure

Question 45

Which of the following would be helpful to hemorrhagic shock victims? a. Keep them on their feet b. Warm them up c. Give them fluids to drink d. Maintain their blood pressure with catecholamine-type drugs.

Answer 45

C/D

Question 46

Left ventricular chamber enlargement with congestive heart failure increases the wall tension required to generate a given systolic pressure. True or false?

Answer 46

TRUE

Question 47

Your 70-year-old, 70-kg patient has an ejection fraction of 70%. Left ventricular end-diastolic volume is 100 mL. Which of the following statements best !ts these data? a. Stroke volume is approximately 30 mL b. Left ventricular end-systolic volume is approximately 70 mL c. Your patient may be dehydrated d. Your patient may be suffering from chronic systolic heart failure e. These are normal values for someone this age

Answer 47

C

Question 48

All the following are compensatory processes that help maintain circulation during states of hypovolemic shock except a. hepatic glycogenolysis to increase extracellular glucose concentration. b. rapid respiratory effort to promote venous return of blood to the heart. c. vasoconstrictive contributions from increases in circulating epinephrine. d. autotransfusion of interstitial fluid into capillary beds. e. increased blood flow to the kidney

Answer 48

E

Question 49

Predict the status of each of the following variables in most individuals with chronic systemic hypertension. a. Cardiac output b. Heart rate c. Arterial pulse pressure d. Total peripheral resistance e. Renal urinary output

Answer 49

All would be normal except D would be increased