Top 550+ Solved Physiology MCQ Questions Answer

a. increased PCO2 has a direct effect on the curve, shifting it to the right

b. 2,3-DPG levels rise as altitude

c. the deoxy form of Hb is in the relaxed state

d. CO moves the curve to the left as it has 100 times the affinity of O2 for Hb

e. P50 is at a PO2 of 40mmHg

a. Fick’s law states that “the volume of gas per unit time that moves across a sheet of tissue is proportional to the area of the sheet, but inversely proportional to its thickness”

b. the Bohr effect is “the effect of PCO2 on the O2 dissociation curve due to the action of PCO2 on H+ concentration”

c. Henry’s law states that “the amount of gas dissolved is proportional to the partial pressure of that gas”

d. the chloride shift is “the diffusion of HCO3 - in to the cell, with the outward diffusion of Cl- ions to maintain electrical neutrality”

e. the Haldane effect is that deoxygenation of the blood increases its ability to carry CO2

a. metabolic acidosis

b. metabolic acidosis with renal compensation

c. respiratory acidosis

d. respiratory acidosis with renal compensation

e. respiratory alkalosis

a. the lung volume at any given pressure during inflation is larger than during deflation

b. the area under the pressure-volume curve is known as the compliance

c. surface tension is the force acting across an imaginary line in the surface of the liquid

d. pressure generated in an alveolus equals 4T/R

e. surfactant, produced by Type I alveolar cells, reduces surface tension in alveoli

a. 2-fold

b. 4-fold

c. 8-fold

d. 16-fold

e. has no effect on resistance

a. segmental bronchii

b. medium-sized bronchii

c. small bronchii

d. large bronchioles

e. terminal bronchioles

a. asthma

b. alveolar oedema

c. pulmonary hypertension

d. atelectasis

e. pulmonary fibrosis

a. sleep

b. increasing age

c. trained athlete

d. morphine

e. decreased PO2

a. 50%

b. 60%

c. 70%

d. 80%

e. 90%

a. the difference between alveolar pressure and the pressure within them

b. the pressure in the pulmonary artery

c. the lung volume

d. the cardiac output

e. the patient’s fluid status

a. males eliminate carboxy haemoglobin faster than females

b. gas around the body is normal air compressed to the same high pressure

c. it produces marked increases in dissolved oxygen in the blood

d. oxygen is administered at up to 3 atmospheres pressure

e. toxicity includes optic neuritis

a. shift to the right of the oxygen dissociation curve

b. increased number of capillaries in peripheral tissues

c. pulmonary vasodilation

d. polycythaemia

e. increased maximum breathing capacity

a. pulmonary stretch receptors lie within the airway epithelial cells

b. J receptors, when stimulated, cause slow deep breathing

c. irritant receptors, when stimulated, send impulses up the vagus in unmyelinated fibres

d. irritant receptors are rapidly adapting

e. increased maximum breathing capacity

a. tidal volume in the average human is 500ml

b. anatomical dead space is the volume of the conducting airway and is about 160ml

c. upper regions of the lung ventilate better than the lower regions

d. you can measure physiological dead space via Bohr’s method to get what is called a Bohr equation which is: VD PACO2-PECO2 VT PACO2

e. None of the above

a. P1-P2

b. area of lung

c. the thickness

d. diffusion constant

e. all of the above