Top 80+ Solved General Physiology MCQ Questions Answer
Q. Action potential initiation in the sinoatrial and atrioventricular nodes results from:
a. Na+ influx
b. K+ influx
c. Ca++ influx
d. Na+ and Ca++ influx
e. increased K+ conductance
Q. Regarding isometric ventricular reaction:
a. it occurs late in diastole
b. ventricular filling occurs
c. intraventricular pressure remains constant during this phase
d. it ends when the AV valve close
e. it ends when the AV valve open
Q. Local vasoconstriction results from:
a. increased potassium concentration
b. increased magnesium concentration
c. increased sodium concentration
d. decrease in pH
e. increased calcium concentration
Q. In compensated low output cardiac failure:
a. venous resistance is decreased
b. cardiac contractility is increased
c. mean systemic filling pressure is decreased
d. right atrial pressure is decreased
e. venous return is decreased
Q. With regard to ascending to high altitudes:
a. there is a linear decrease in inspired oxygen pressures with increasing altitude
b. the partial pressure of water vapour in moist inspired air decreases with PiO2
c. at 19,200m, barometric pressure = 47mmHg, PiO2 then is approx 9mmHg
d. at peak at Mt Everest, barometric pressure = 380mmHg, PiO2 is approx 70mmHg
e. in permanent residents of the Andes, arterial and venous PO2 is half normal levels
Q. A 28-year-old lady has taken an overdose of sedatives causing her to hypoventilate. Given that her arterial PCO2 is now doubled to 80mmHg, which of the following is most likely to be correct, given that she is breathing room air at normal barometric pressures?
a. arterial PO2 will be approximately 70mmHg
b. arterial PO2 will be approximately 35mmHg
c. arterial Hb O2 saturation will be approximately 50%
d. arterial Hb O2 saturation will be approximately 80%
e. arterial Hb O2 saturation will be approximately 27%
Q. Which of the following has the greatest effect on the ability of the blood to transport O2?
a. the capacity of the blood to dissolve O2
b. the amount of Hb in the blood
c. the pH of the plasma
d. the CO2 content of red blood cells
e. the temperature of the blood
Q. The Haldane effect describes:
a. the shift to the right of the O2 dissociation curve caused by increased PCO2
b. the enhanced loading of CO2 iii the presence of deoxygenated Hb
c. the shift of chloride ions into red blood cells to balance HCO3 shift from those cells
d. the action of carbonic anhydrase on carbonic acid
e. none of the above
Q. With regard to CO2 carriage in the blood:
a. dissolved CO2 has an insignificant role in the carriage of CO2 in the blood
b. HCO3 production is fast in plasma
c. ionic dissociation of carbonic acid in the red cell is fast without an enzyme
d. the CO2 concentration in blood is independent of the saturation of haemoglobin with oxygen
e. the majority of CO2 is carried in the blood in the forms of dissolved CO2 and carbamino-compounds
Q. Substances cleared from the circulation by the lungs include all the followingEXCEPT:
a. angiotensin H
b. serotonin
c. leukotrienes
d. bradykinin
e. prostaglandin
Q. Increased lung compliance is associated with:
a. increasing age
b. increasing pulmonary venous pressure
c. high expanding pressures
d. interstitial fibrosis
e. low lung volumes associated with hypoventilation
Q. The following physiological events that occur in the body are listed in random sequence:a. decreased CSF pHb. increased PaCO2c. increased CSF PCO2d. stimulation of medullary chemoreceptorse. increased PACO2What is the usual sequence?
a. a, b, c, d, e
b. d, a, c, b, e,
c. c, d, e, b, a,
d. e, b, c, a, d,
e. e, c, b, d, a
Q. In relation to acid base balance in the body:
a. respiratory compensation in metabolic alkalosis is limited by carotid and aortic chemoreceptor response
b. HCO3 concentration will decrease in compensated respiratory acidosis
c. the rate of renal H+ secretion is not affected by PCO2 in respiratory acidosis
d. chloride excretion is decreased in respiratory acidosis
e. hepatic glutamine synthesis is decreased in chronic metabolic acidosis
Q. The functions of tropomyosin in skeletal muscle include:
a. releasing Ca++ after an action potential
b. sliding on actin to produce shortening
c. binding to myosin during contraction
d. acting as a “relaxing protein” at rest by covering up the sites where myosin binds to actin
e. generating ATP which passes to the contractile mechanism
Q. Regarding the autonomic nervous system:
a. does not have a reflex like somatic nervous system
b. has dopamine as the main transmitter
c. has cholinergic division which increases activity of the intestinal musculature and increases gastric secretion
d. neurotransmitter noradrenaline is metabolised by pseudocholinesterase
e. is not involved with visceral sensation