Section 1:
Answer the following using:
1. The maximum diastolic potential of the sinus node action potential _______ when the vagus nerve is stimulated.
3.
The overshoot of the sinus node action potential __________ when 1 mM tetrodotoxin (TTX) is added to the tissue bath.
4.
The overshoot of the Purkinje fiber action potential __________ when 1 mM D600 (calcium channel blocker) is added to the tissue bath.
5.
The membrane potential of vascular smooth muscle cells ________ after an
increase in Cl- conductance.
Section
2: Answer the following
using:
A = increase
B = not change
C = decrease
6.
The activity of the sodium-potassium pump in ventricular muscle will
_________ immediately after 100 mM
ouabain is added to the bathing medium.
7.
The conduction velocity of a Purkinje fiber will _________ when
extracellular [K+] is reduced from 4 to 1 mM.
8.
The duration of the QRS complex will ________ when the plasma [K+]
is increased from 4 to 8mM.
9.
The duration of the diastolic interval will ________ when the temperature
is reduced from 37o C to 30o C.
10.
A decrease in the interval between successive heart beats will __________
the residual volume of the left ventricle.
11.
An increase in preload will __________ velocity of contraction.
12.
Shear rate will __________ as blood flows from the aorta to arterioles.
13.
Following the development of an aortic aneurysm, the Reynold’s number
in this segment will ___________.
14.
Following an infusion of a physiological dose of epinephrine, total
peripheral resistance will _________.
15. At low lung volumes, expiratory flow (as measured on an expiratory flow-volume curve) will _________ with increasing expiratory effort.
16. At high lung volumes, expiratory flow (as measured on an expiratory flow-volume curve) will __________ with increasing expiratory effort.
17. During an operation, the arterial PCO2 of an anesthetized patient is monitored. A mechanical ventilator is ventilating the patient, and the initial value (PCO2 40 mmHg) is normal. If the ventilation is increased, PCO2 will __________.
18.
Recruitment and distension in response to increased pulmonary arterial or
pulmonary venous pressure will __________ pulmonary vascular resistance.
19.
If alveolar pressure is raised during positive pressure ventilation, the
amount of lung functioning under “Zone 1” conditions will _________.
20. The Haldane effect demonstrates that decreased O2 saturation (i.e., low PO2) will _________ the CO2 content of the blood.
21. A patient with congenital heart disease has a right-to-left shunt and an arterial PO2 of
60 mmHg during air breathing. When he is given 100% O2, you would expect his arterial PO2 to __________.
22. The magnitude of the ventilatory response to hypoxia will _________ following an increase in PCO2 from 40 to 50 mmHg.
23.
Treatment with an angiotensin-converting enzyme inhibitor will ________
proximal tubular sodium reabsorption.
24.
Infusion of HCl will ________ renal ammonia production.
25. Increased filling of the cardiac atria above normal will _________ sodium permeability of the apical membranes of inner medullary principal cells.
26.
Hypokalemia will tend to ___________ secretion of aldosterone.
27.
Increased flow through the distal tubule during diuretic treatment will
___________ potassium secretion in this segment.
28.
Decreased flow, to a subnormal rate, through the ascending limb of Henle
will _________ renin secretion.
29.
Increased excretion of solutes will __________ the excretion of water.
30.
Increased afferent arteriolar resistance will __________ the value of the
filtration fraction.
Section
3: For each of the
following, choose the single best response.
31.
Upon binding of norepinepherine to a b-adrenergic
receptor on the surface of a working ventricular myocyte,
a.
Ca2+-dependent protein kinase (PKC) activity is increased.
b.
the ejection fraction is increased.
c.
the binding affinity of Tropnin I for Ca2+ increases.
d.
Na+,K+-ATPase activity is decreased.
e.
the heart rate will increase.
32.
Which of the following would result in an increase in stroke volume?
a.
hypovolemia
b.
application of propranolol at the sinoatrial node
c.
an increase in total peripheral resistance
d.
an increase in heart rate from 70 to 130 bpm
e.
administration of Verapamil (Ca2+ channel blocker)
33.
Aortic stenosis (narrowing of the aorta) would cause which of the
following?
a.
a decrease in stroke volume
b.
a decrease in atrial natriuretic peptide (ANP) secretion
c.
a decrease in heart rate
d.
a decrease in central venous pressure
e.
no change in peak ventricular pressure
34.
Which of the following cardiac effects does
NOT occur during a sympathetic stimulation?
a.
The speed of contraction of a ventricular myocyte increases.
b.
The speed of relaxation of a ventricular myocyte increases.
c.
Intracellular Ca2+ concentrations increase due to a decrease
in the activity of the Na+/Ca2+ exchanger.
d.
Central venous pressure will decrease.
e.
The membrane potential of a ventricular myocyte during phase 2 becomes
more positive.
35.
Using Fick’s principle, what is the oxygen consumption of a patient
with an oxygen content in the pulmonary artery of 0.14 mL O2 / mL
blood, an oxygen content in the vena cava of 0.18 mL O2 / mL blood,
an oxygen content in the pulmonary vein of 0.21 mL O2 / mL blood, and
a cardiac output of 4.5 L blood / min?
a.
315 mL O2 / min
b.
135 mL O2 / min
c.
250 mL O2 / min
d.
180 mL O2 / min
36. Regarding AFTERLOAD which of the following statements is TRUE?
a. When afterload is increased (at constant preload) the velocity of contraction decreases.
b.
Incremental increases in afterload produce progressively higher peak
systolic pressures.
c.
Force of contraction and velocity of contraction are inversely related
(i.e. with no afterload, the velocity of contraction is maximal)
d.
An increase in vascular Total Peripheral Resistance (TPR) results in an
increase in afterload.
e.
All of the above are true.
|
37.
Which point most closely corresponds to the second heart sound?
a.
A
b.
B
c.
C
d.
D
e.
E
38. Which point most closely correlates with the T wave of an EKG?
a.
A
b.
B
c.
C
d.
D
e.
E
39.
On this figure, which of the following occurs during the overlap of the
ventricular pressure and the aortic pressure curves?
a.
the c wave of the venous pulse
c. the QRS complex of the EKG
d.
the peak rate of aortic blood flow
40. Which point is closest to the smallest ventricular volume?
a.
A
b.
B
c.
C
d.
D
41. Regarding PRELOAD which
of the following statements is FALSE?
a.
Increasing end diastolic volume can increase preload.
b.
At very high preloads, peak pressure development in systole is reduced.
c.
Velocity of contraction is maximal during the second half of
isovolumetric contraction.
d.
An increase in preload can lead to an increase in cardiac output.
e.
None of the above are false.
42. The figure above shows the changes in left ventricular developed pressure when the sarcomere length is modified. (Afterload is kept constant). What is TRUE regarding this graph?
a.
When the sarcomere length is changed from point B to point C, there is no
change in preload .
b.
Point D represents a decrease in developed force due to an excess of
stretching of the sarcomere.
c.
The optimal sarcomere length will be found between points A and B
d.
All of the above are true.
e.
None of the above are true.
This figure represents
the changes in ventricular volume (top trace), aortic pressure (middle trace)
and venous pressure (bottom trace) over time; before, during and after a
stimulus that increases aortic pressure. The stimulus is applied at the arrow
and is increased in two subsequent steps; it starts decreasing in steps at about
80 seconds. (Experimental values obtained from a dog's heart)
43. If the heart rate in
the above figure is constant at 80 bpm, what would be the cardiac output when
afterload is increased at the arrow (aortic pressure is increased to 95 mm Hg)?
a.
1.4 L/min
b.
560 mL/min
c.
5.6 L/min
d.
960 mL/min
e.
800 mL/min
44. A man was injected with 4 grams of inulin and 15 miligrams of Evans blue. Following equilibration, an arterial sample was obtained which had an inulin concentration of 0.15 mg/mL; an Evans blue concentration of 4.5 mg/mL; and a hematocrit of 38%. During the equilbration period, the man voided 350 mL of urine that contained 6 mg/mL inulin and no Evans blue. The interstial fluid volume of this individual is:
a. 12.7 L.
b. 9.4 L.
c. 16.0 L.
d. 5.9 L.
e. cannot be determined from this information
45. What is the total peripheral resistance (TPR) within the systemic circulation in a patient that has a resting cardiac output of 5.5 L/min; an arterial systolic pressure of 130 mmHg, and a diastolic pressure of 95 mmHg?
a.
2.0 mmHg x min / L
b.
6.4 mmHg x min / L
c.
13.6 mmHg x min / L
d.
19.4 mmHg x min / L
e.
TPR cannot be determined from this information
46.
A patient with aortic stenosis would be expected to display ALL of
the following EXCEPT:
a.
decreased coronary blood flow.
b.
increased pulse pressure.
c.
a murmur in this region.
d.
elevated left ventricular pressure during systole.
e.
both a and d
47. Which of the following will enhance vascular tone?
a.
a Ca2+ channel blocker
b.
a b2
agonist
c.
inositol triphosphate (IP3)
d.
hyperpolarization of cell membrane
e.
none of the above
48.
In a blood vessel that displays pressure autoregulation, a decrease in
perfusion pressure will result in:
a.
constriction of the arteriole.
b.
a decrease in vascular resistance.
c.
release of nitric oxide (NO) from the endothelium.
d.
release of NO from the smooth muscle cells.
e.
both b and c
49. Consider two solutes, X and Y. Both have the same molecular size, but differ in terms of their lipid solubilities such that X is lipid soluble and Y is not. In regard to capillary permeability, which of the following would be expected?
a.
Within continuous capillaries of the heart, the relative permeabilities
of X and Y would be the same.
b.
Within continuous capillaries of the heart, both solutes are restricted
to the small pores.
c.
When compared to continuous capillaries, the permeability of Y is
significantly higher in fenestrated capillaries whereas the permeability of X is
basically the same in continuous and fenestrated capillaries.
d.
Within continuous capillaries of the heart, X is restricted to small
pores, while Y is only found in pinocytotic vesicles.
e.
Neither are permeable at all.
50.
During congestive heart failure, peripheral edema will result due to an
imbalance of Starling forces involving:
a.
increased capillary hydrostatic pressure, Pc.
b.
increased plasma oncotic pressure, pp.
c.
decreased interstitial fluid hydrostatic pressure, Pi.
d.
increased interstitial fluid oncotic pressure, pi.
e.
all of the
above.
51.
The Valsalva maneuver can provide a simple test of the effectiveness of the
baroreceptor reflex. Using the
phase designations labeled on the pressure trace shown above, describe what
would happen in a patient with a compromised baroreceptor reflex.
a. The aortic pressure would initially decrease following the increase in intra-thoracic pressure (phase 1).
b.
Aortic pressure would not decrease in the early part of phase 2.
c.
The aortic pressure would not moderate during the latter part of phase 2,
but would continue to fall throughout the period in which intra-thoracic
pressure is elevated.
d.
Following the return of intra-thoracic pressure to normal as the air is
released from the lung, the aortic pressure would continue to decrease
throughout phases 3 and 4.
52.
Within vascular smooth muscle, Ca2+ binds to:
a.
actin.
b.
myosin.
c.
myosin light chain kinase.
d.
calmodulin.
e.
troponin C.
53.
Among the number of compensatory mechanisms that become activated in
response to hemorrhage, which of the following will DECREASE?
a.
heart rate
b.
vascular smooth muscle contractility
c.
total peripheral resistance
d.
angiotensin II levels
e.
hematocrit
54.
As a normal healthy individual rises from a supine position, one would
expect all of the following EXCEPT:
a. a decrease in stroke volume.
b. an increase in heart rate.
c.
an increase in baroreceptor impulses arriving at the nucleus tractus
solitarius (NTS).
d.
an increase in total peripheral resistance.
e.
venous pooling in the lower limbs.
55.
The conducting airways
a.
transport air between the environment and the gas exchange regions of the
lung.
b.
do not participate in gas exchange because they contain no alveoli.
c.
comprise the anatomical dead space in a healthy individual.
d.
include the respiratory bronchioles.
e.
a, b, and c
56.
Transpulmonary pressure is equal to
a. atmospheric pressure minus alveolar pressure.
b.
alveolar pressure minus intrapleural pressure.
c.
intrapleural pressure minus atmospheric pressure.
d.
intrapleural pressure minus alveolar pressure.
57.
At functional residual capacity (end expiration),
a. the elastic recoil of both the lung and chest wall are directed outward.
b.
the elastic recoil of both the lung and chest wall are directed inward.
c.
the inward directed elastic recoil of the lung is greater than that of
the outward directed elastic recoil of the chest wall.
d.
the inward directed elastic recoil of the lung balances the outward
directed elastic recoil of the chest wall.
58.
Lung compliance
a. can only be measured when air is flowing into or out of the lungs.
b.
increases in restrictive pulmonary disease (i.e., pulmonary fibrosis).
c.
represents the relationship between changes in the pressure distending
the alveoli and the corresponding changes in lung volume.
d.
is greatest at high lung volumes.
e.
a, b, and c
59.
Airway resistance
a.
is extremely high at low lung volumes because bronchial smooth muscle
actively contracts at low lung volumes.
b. is minimized by dynamic compression of the airways.
c.
can only be measured when air is flowing into or out of the lungs.
d.
decreases during stimulation of the parasympathetic postganglionic fibers
innervating the bronchial smooth muscle.
e.
is higher in the small airways than in the medium sized bronchi because
the small airways are arranged in parallel.
60.
Which of the following lung volumes can NOT be measured with a
simple spirometer?
a.
tidal volume
b.
inspiratory reserve volume
c.
expiratory reserve volume
d.
residual volume
61.
Which of the following factors may reduce the FEV1 in a
patient with chronic obstructive pulmonary disease (COPD)?
a. excessive secretions in the airway
b.
increased elastic recoil of the lung
c.
increased radial traction on the airways
d.
restricted expansion of the lung
e.
All of the above factors may contribute to reduced FEV1.
62. The inspiratory flow-volume curve is particularly valuable for
a. differentiating between chronic bronchitis and emphysema.
b.
detecting fixed upper airway obstruction.
c.
measuring the response to bronchodilator drugs.
d.
measuring the resistance of the very small airways.
63.
Which patient has the highest alveolar ventilation?
a.
Tidal volume=1000 mL; Frequency=8 breaths/min; Dead space volume=150 mL
b.
Tidal volume=500 mL; Frequency=16 breaths/min; Dead space volume=150 mL
c.
Tidal volume=250 mL; Frequency=32 breaths/min; Dead space volume=150 mL
d.
Alveolar ventilation is the same in all cases.
64. A
healthy person, seated upright, begins to inspire from Functional Residual Capacity (FRC) to Total Lung Capacity (TLC).
The inspired gas is labeled with Xenon133.
Most of this radioactive gas will be found
a. in the conducting airways (i.e., anatomical dead space).
b.
in the
alveoli in the upper portions of the lung.
c.
in the
alveoli in the lower portion of the lung.
d.
uniformly
distributed to all alveoli.
65.
In comparison to systemic arterial vessels, pulmonary arterial vessels
have
a.
thinner walls and greater internal diameters than corresponding branches
of the systemic vessels.
b.
lower hydrostatic pressures than those found in systemic arteries.
c.
the same vascular smooth muscle response to hypoxia.
d.
a and b
e.
a, b, and c
66.
Which of the following is FALSE regarding diffusion of O2
and CO2 in the lungs?
a.
CO2 is approximately 20 times more diffusible than O2.
b.
Under normal conditions, diffusion of both O2 and CO2
follow a similar time course.
c.
The partial pressure gradient for diffusion of O2 is greater
than the partial pressure gradient for diffusion of CO2.
d.
If the blood-gas barrier is markedly thickened, diffusion of O2
is impaired.
e.
The surface area available for diffusion is reduced during exercise due
to increased blood flow.
67.
Which of the following has the greatest effect on the ability of blood to
transport oxygen?
a. capacity of the blood to dissolve oxygen
b.
amount of hemoglobin in the blood
c.
carbon dioxide content of the red blood cells
d.
pH of the plasma
e.
temperature of the blood
68.
In peripheral capillaries, more O2 can be unloaded from blood
at a given PO2
when:
a.
PCO2
is raised.
b.
blood pH is raised.
c.
blood temperature is reduced.
d.
the concentration of 2,3-DPG in the red blood cell is reduced.
69.
Most of the CO2 in blood is carried as:
a. physically dissolved.
b.
carbamino compounds with plasma proteins.
c.
carbamino Hb.
d.
bicarbonate ions (HCO
) in the plasma.
e.
bicarbonate ions in red blood cells.
70.
The apex, compared with the base, of the upright lung
a.
has a higher ventilation-perfusion ratio.
b.
has higher compliance.
c.
has smaller alveoli.
d.
has a higher PCO2.
e.
has a lower PO2.
71.
What mechanism is responsible for most, if not all, of the arterial
hypoxemia associated with pulmonary disease (e.g., COPD; interstitial lung
disease)?
a. hypoventilation
b.
diffusion impairment
c.
shunt
d.
ventilation-perfusion inequality
72.
Variations in which of the following components of blood or cerebrospinal
fluid will NOT affect respiration?
a.
arterial CO2 concentration
b.
arterial H+ concentration
c.
arterial O2 content
d.
cerebrospinal fluid CO2 concentration
e.
cerebrospinal fluid H+ concentration
73.
Voluntary apnea (breath-holding) for 120 seconds will
a.
reduce alveolar PO2.
b.
increase alveolar PCO2.
c.
decrease arterial pH.
d.
stimulate both the arterial and central chemoreceptors.
e.
all of the above
74. Which
of the following is
NOT a characteristic of the renal circulation?
a.
The
endothelial cells of the afferent arterioles release vasodilatory prostaglandins
in response to angiotensin II.
b.
The
glomerular capillary bed has a low resistance owing to the high number of
parallel capillary branches.
c.
The
innervation of the intrarenal arterial system consists mainly of sympathetic
nerves.
d.
Both
afferent and efferent arterioles will constrict in response to a rise in
arterial blood pressure to a supranormal level.
75. Which
of the following statements about the glomerulus is FALSE?
a.
Surface
charges on the glomerular basement membrane are the basis of charge perm
selectivity of the glomerular capillary wall.
b.
Filtration
pressure equilibrium indicates that net filtration pressure falls to zero before
the blood leaves the glomerular capillaries.
c.
The value
of the ultrafiltration coefficient (Kf) will increase when mesangial
cells contract.
d.
The width
of the slit pores is an important determinant of the hydraulic conductivity of
the glomerular capillary wall.
76. Which
of the following is FALSE?
a. The endothelial cells of the renal arterial system release nitric oxide, but only in response to acetylcholine.
b.
Significant
loss of extracellular fluid will trigger constriction of both the efferent and
afferent arterioles, resulting in a rise in the filtration fraction.
c.
Atrial
natriuretic peptide (ANP) dilates the afferent arteriole, leading to a rise in
GFR and RBF.
d.
Tubuloglomerular
feedback is a mechanism that acts to balance the rate of glomerular filtration
with the reabsorptive capacity of the proximal tubule and Henle’s loop.
77. Which
of the following is FALSE?
a.
The
majority of the sodium entry through the apical membrane of proximal tubular
cells is the result of sodium-dependent secondary active transport of other
solutes.
b.
Proximal
tubular reabsorption is dependent on, but is not regulated by, glucocorticoids.
c.
In the
proximal tubule, the reabsorption of glucose and other organic substrates is
saturable, and the Transport maximums of these processes are such that small
increases in their plasma concentrations always result in increased urinary
excretion of the solutes.
d.
In the
second half of the proximal tubule, the cycling of organic bases across the
apical membrane results in substantial uptake of sodium and chloride ions into
the cells.
78. Which
of the following is FALSE?
a.
In the
initial portion of the distal convoluted tubule, apical transport of sodium is
mediated by a sodium-chloride cotransporter.
b.
In the
principal cells of the cortical collecting ducts, chloride ions are transported
through the tight junctions.
c.
In the
principal cells of the collecting duct, binding of anti diuretic hormone (ADH)
will lead to the reversible insertion of vesicles containing water channels
(aquaporins) into the apical membrane.
d.
The fluid
in the descending limb of Henle equilibrates with the medullary interstitium by
osmosis and, to a lesser extent, by passive diffusion of solutes into the
tubular fluid.
79. A
person is infused with PAH. After
equilibration, urinary PAH excretion is
120 mg/min, PPAH is 0.20 mg/mL. What is
renal plasma flow?
a.
120
mL/min
b.
400
mL/min
c.
600
mL/min
d.
None of
the above
80. Consider
the figure above. Which of the following statements best describes the transport
of the freely-filtered substance?
a.
The
substance is reabsorbed by a carrier-mediated process.
b.
The
plasma threshold concentration of the substance is 2 mg/mL.
c.
The Tm
is 100 mg/min.
d.
All of
the above are true.
81. A
company measures the renal handling of a new painkiller.
The drug is freely filtered and not metabolized in the body.
Renal studies show that the clearance of the drug is the same as that of
inulin at all tested plasma concentrations.
How is the drug handled by the kidney tubules?
a. The drug is not reabsorbed or secreted by the renal tubules.
b. The drug is subjected to net secretion by the renal tubules.
c.
The drug
is subjected to net
reabsorption by the renal tubules.
d.
There is
no net transport of the drug by the
tubules.
82. Which
of the following statements is FALSE?
a. Dietary sodium intake has only a minor effect on blood pressure in a normal, healthy person.
b. An acute rise in arterial blood pressure will cause a rise in renal sodium excretion that is independent of changes in GFR.
c.
The
addition of 150 mmoles of NaCl to the extracellular fluid will increase plasma
osmolarity and increase intracellular fluid volume.
d.
During a
period of negative sodium balance, the renal excretion of sodium exceeds dietary
sodium intake.
83. Which
of the following statements is FALSE?
a. The washout of urea from the medulla during a water diuresis is a consequence of the low water permeability of the distal tubules and collecting ducts.
b. The term countercurrent exchange refers to the cycling of solute between the descending and ascending vasa recta.
c.