Friday, January 1, 2010

29 - Physiology mock test 1

1)In Wallerian degeneration of a peripheral nerve :

a) The axons regenerate at a rate of 1 cm / day.
b) Occurs in the distal portion of the broken axon leaving an empty tubule
c) Is a feature of neuropraxia
d) All the above

2) Surfactant is a substance that :
a) Is produced in the liver of new borns
b) Is important in the new borns but is of little importance in adults
c) Is produced in the basement membrane of lungs
d) Helps in prevention of collapse of the alveoli

3) Calcium enters the cardiac cell during:
a) Rapid upstroke of the action potential
b) Down slope of the action potential
c) Plateau phase of the action potential
d) Slow diastolic depolarization {phase 4} of the action potential .

4) The functional residual capacity of lung is defined as:
a) Tidal volume & residual Volume
b) Tidal Volume & expiratory reserve volume
c) Inspiratory reserve volume & tidal volume
d) Residual volume & expiratory reserve volume

5) The metabolic function of parathormone includes all these except :
a) Mobilizes calcium from bone
b) Decreases renal tubular reabsorption of calcium
c) Promotes renal production of 1,25 hydroxy cholecalciferol
d) Lowers serum phosphate level

6) The need to vitamin B12 & folic acid in the formation of RBC's is primarily to effect on :
a) Synthesis & release of erythropoietin from the kidneys
b) Absorption of Iron from GUT
c) DNA synthesis in the bone marrow
d) Hemoglobin formation in the RBC's.

7) Intra pulmonary shunting refers to:
a) anatomical dead space
b) alveolar dead space
c) Wasted ventilation.
d) Perfusion in excess of ventilation

8) During regeneration after axonotmesis , the usual delay before the start of growth of axons in the distal direction is about :
a) 2 days
b) 10days
c) 3 weeks
d) 2 months

9) Absorption of H2O in PCT is characteristic by all except:
a) Vasopressin dependent
b) 60% of water is absorbed
c) Depends on solutes
d) Vasopressin independent

10) Cerebellar Ataxia is characterized by all except:
a) Resting tremor
b) Dysdiadochokinesis
c) Ataxia
d) Hypotonia

11) Parasympathetic stimulation of tissues in walls of bronchioles causes:
a) Bronchoconstriction
b) Bronchodilation
c) Increased blood flow
d) Dilatation of alveoli.

12) A healthy man is flying in a plane that has been pressurized to 10,000 feet (523 HG) . Which of the following statements regarding effects of this barometric pressure is true ?
a) It will cause a modest reduction in arterial Po2 .
b) It will not affect alveolar Po2 because inspired O2 remains at 0.21
c) Will be associated with significant desaturation of arterial Hemoglobin
d) None of the above

13) Of the following cell types, which would contain many mitochondria in the apical portion of the cell?
a) Smooth muscle cells
b) Ciliated epithelium cells
c) Steroid secreting cell
d) Skeletal muscle cells

14) Which of the following statements most accurately describes features of neuromuscular transmission?
a) Each muscle fiber contains multiple axon terminals
b) The end plate is highly enriched in electrically excitable gates
c) Enzymatic degradation of the transmitter can terminate transmission
d) Acetyl choline causes chloride channels to open as a result of membrane depolarization.

15) Which of the following statements regarding expiration is correct ?
a) At lung volumes close to vital capacity [VC] ,expiratory air flow is independent of expiratory effect
b) at lung volumes close to VC ,airway resistance is at its peak
c) At lung volumes close to VC , expiratory air flow increases with pleural pressures.
d) None of the above

16) RNA processing can be best described by which of the following statements?
a) It occurs in the cytoplasm
b) It includes the methylation of nucleotides in RNA
c) It results in the formation of new covalent bonds between RNA & DNA
d) It includes the addition of a tail of polyadenylic acid at the 5'end

17) The upstroke of ventricular action potential is primarily due to which one of the following actions?
a) An inward flux of Ca2
b) An inward K + current
c) An outward K+ current
d) An inward Na + Current

18) Which of the statements about acetyl choline release & deactivation is true?
a) ACH release is blocked by toxin associated with Clostridium tetanae
b) Uptake of Ach into the presynaptic receptor is the most important mechanism in terminating the Ach signal
c) Inhibitors of the enzyme MAO are important in the treatment of depression because they inhibit the breakdown of ach into its constituents .
d) The influx of Ca2+ into the depolarized axon terminal is a prerequisite for the release of stored Ach

19) All the following thalamic nuclei are connected to the basal ganglia except
a) Ventrolateral
b) medial central
c) Pulvinar
d) Ventro anterior

20) All the statements concerning mammalian chromosomes are true except :
a) DNase 1 can be used to treat chromosomes to determine inactive regions of DNA.
b) Approximately 7% of the sequences contained in the eukaryotic genome are copied into RNA.
c) Heterochromatin is a term used for inactive DNA and euchromatin is a term used for these regions of the DNA that are transcriptionally active .
d) None

Solution to mock test 1

Question 1=b
Question 2=d
Question 3=c
Question 4=b
Question 5=b
Question 6=c
Question 7=d
Question 8=b
Question 9=a
Question 10=a
Question 11=a
Question 12=a
Question 13=b
Question 14=c
Question 15=c
Question 16=b
Question 17=d
Question 18=d
Question 19=c
Question 20=a

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