Top 550+ Solved Physiology MCQ Questions Answer

a. hyperventilation occurs due to hypoxic stimulation of peripheral chemoreceptors

b. pro-erythroblasts mature into erythrocytes more rapidly than normal

c. renal bicarbonate excretion increases

d. increased numbers of mitochondria appear in the tissues

e. FiO2 decreases with increasing altitude

a. conversion of AI to AII by ACE

b. metabolism of AII

c. inactivation of bradykinin

d. removal of serotonin

e. metabolism of arachidonic acid metabolises

a. O2 toxicity causes convulsion

b. O2 at 100% in premature infants causes retrolental fibroplasia

c. acclimatisation to high altitudes include a shift to the left of the O2 dissociation curve

d. polycythaemia is a feature of acclimatisation

e. acute mountain sickness is due to hypoxaemia and alkalosis

a. medullary centres are close to but separate from central chemoreceptors

b. during quiet respiration, expiration is a passive event

c. inspiratory medullary neurons supply both phrenic nerves

d. ventral medullary neurons are expiratory and do not discharge spontaneously

e. inspiratory medullary neurons discharge spontaneously at a rate of 12-15 times/minute

a. O2

b. N2O

c. CO2

d. CO

e. halothane

a. it is calculated by Bohr’s method

b. the normal value is about 150ml

c. it increases with large inspirations

d. depends on the size of the subject

e. it is equivalent to the conducting zone

a. haemoglobin S causes the O2 curve to shift to the left

b. the O2 dissociation curve is shifted to the right by an increased PCO2, H+ concentration and temperature

c. carboxy haemoglobin has 240 times the affinity of O2 for Hb

d. COHB shift the O2 dissociation over to the left

e. it is equivalent to the conducting zone

a. central chemoreceptors are located in the medulla oblongata

b. hypoxia makes an individual more sensitive to increases in arterial carbon dioxide

c. arterial oxygen less than 70mmHg markedly stimulates respiration via the carotid bodies

d. carotid bodies have the highest blood flow, per unit time per 100g, of any tissue in the body

e. carbon dioxide is more important than oxygen in respiratory control

a. Va = (VCO2/PCO2) x K

b. V = (A.D.(P1 – P2))/T

c. pH - -LOG[H+]

d. P1V1 = P2V2

e. V1/V2 = T1/2

a. it predominantly consists of phospholipid

b. it is increased by long-term 100% oxygen therapy

c. hydrophobic “tails” face into alveolar lumen

d. it is decreased by cigarette smoking

e. pulmonary oedema is a consequence of its absence

a. increased temperature

b. increased PCO2

c. increased H+

d. increased DPG

e. increased carboxy haemoglobin

a. the energy cost of breathing is up to 10% of total energy expenditure

b. total pulmonary ventilation increases by up to 20 fold

c. total oxygen consumption increases by up to 20 fold

d. total carbon dioxide production increases by up to 40 fold

e. P5O increases

a. vital capacity + tidal volume

b. vital capacity + functional residual capacity

c. tidal volume + residual volume

d. functional residual capacity + tidal volume

e. vital capacity + residual volume

a. functional residual capacity is the equilibrium volume when elastic recoil of lung is balanced by normal tendency for chest wall to spring out

b. hysteresis is due to frictional resistance to air movement

c. compliance is greater in expiration than in inspiration

d. compliance is increased in emphysema

e. compliance is a dynamic measure of lung and chest wall recoil

a. the right and left ventricles perform the same amount of work, because the same volume of blood is pumped by each

b. the cross sectional shape of both ventricles is approximately cylindrical

c. the right ventricle pumps by a bellows type mechanism

d. the left ventricle pump action is via reducing cross-sectional area, as a function of radius cubed

e. in pulmonary disease the right ventricle hypertrophies and assumes a crescented shape in cross section