PNB PAST QUESTIONS

A naive T cell that interacts only via its T cell receptor/CD4 complex with an antigen presenting cell (APC):

A. becomes fully activated.
B. up-regulates IL-2 expression, but does not proliferate.
C. shows no effect.
D. becomes anergic.

D. becomes anergic.

In an experiment, a virus is injected into a rabbit and the rabbit is allowed to make antibodies for the viral antigen. These antibodies are then removed from the rabbit plasma and injected into a human to help deal with the same viral disease. This would be an example of…
A) innate immunity
B) active immunization
C) passive immunization
D) natural immunity
E) autoimmunity

C) passive immunization

A fluid sample contains a large
amount of IgA . This fluid is…
A) blood
B) lymph
C) serum
D) tears
E) intracellular

D) tears

Interferons assist the immune response in all of the following ways EXCEPT…
A) inhibition of viral replication in host cells
B) activation of natural killer cells
C) increasing antigen presentation to lymphocytes
D) cause a fever

D) cause a fever

Your patient, an elderly woman, insists her asthma is exacerbated by her least favorite television show. While explaining that her dislike for the show’s host may be a contributing factor, you explain that an asthma attack is caused by substances released from mast cells, which cause:
A. bronchoconstriction and inflammation.
B. smooth muscle dilation.
C. decreased capillary permeability and fluid leakage.
D. bronchodilation and capillary permeability

A. bronchoconstriction and inflammation.

T cells do not…
A. express CD3
B. produce cytokines to help other cell types.
C. mediate their functions by cell to cell contact.
D. recognize protein antigens without APC cells’ associated.
E. all of the above.

E. all of the above.

In a routine examination, some blood is taken and analyzed. The results show a high IgM level for the mumps antigen. This would
indicate…
A. The person has just recovered from mumps
B. The person is just coming down with mumps
C. The person is allergic to mumps
D. The person is immune to mumps
E. None of the above.

B. The person is just coming down with mumps

TCR diversity is determined by…
A. genetic rearrangement of genes encoding α and β chains.
B. a process identical to those used by immunoglobulins.
C. switch regions between variable, diversity, and
joining exons.
D. A and B only.
E. All of the above.

D. A and B only.

Type II alveolar cells can release ___ to improve lung
compliance and ____ to bolster non-specific defense of the lung. Hint, there are precursor monocytes in the lungs.
A) mucus, G-CSF
B) surfactant, GM-CSF
C) antibodies, erythropoietin

B) surfactant, GM-CSF

People with COPD suffer from chronic hypoxia. How might you treat this patient?
A) supplemental oxygen.
B) stimulate baroreceptors to increase parasympathetic drive to the heart.
C) administer a β-adrenergic receptor agonist.
D) none of the above.

A) supplemental oxygen.

If vital capacity decreases with age but total lung capacity does not change,
which lung volume most likely changed and in which direction?
A) Expiratory reserve volume increased.
B) Residual volume must increase.
C) Inspiratory reserve volume must decrease.
D) Tidal volume must decrease.
E) Tidal volume must increase.

B) Residual volume must increase.

What happens to plasma pH during hyperventilation?
A. Alveolar CO2 increases and so H+ increases
B. Alveolar O2 increases and so H+ increases
C. Based on Haldane effect, Hb will buffer more H+ and so plasma pH decreases
D. Alveolar CO2 decreases and so H+ decreases and plasma pH increases

D. Alveolar CO2 decreases and so H+ decreases and plasma pH increases

How does an increase in plasma pH affect Hb-O2 binding?
A. Hb-O2 binding curve shifts left indicating an increase in Hb-O2
B. P50 increases indicating a decrease in Hb-O2 affinity and so less O2 will be bound to Hb
C. Hb-O2 binding curve will shift right
D. nothing

A. Hb-O2 binding curve shifts left indicating an increase in Hb-O2

How does the chloride shift contribute to CO2 transport?
A) it prevents the dissociation of H2CO3 from reaching equilibrium (i.e., drives reaction to right).
B) chloride ions bind Hb and shift the O2 dissociation cure to the left.
C) the binding of HCO3- to Hb decreases Hb’s affinity for O2.
D) It limits the formation of HCl in plasma

A) it prevents the dissociation of H2CO3 from reaching equilibrium (i.e., drives reaction to right).