All Free Physiology MCQs with Answers

• A. Testosterone and F.S. H
• B. Thyroxine and parathormone
• C. A.D.H. and Oxytocin
• D. Insulin and glucagon

Explanation: FSH acts on Sertoli cells to support sperm production, while testosterone from Leydig cells is also required for normal spermatogenesis.

• A. Radio immune assay
• B. Latex agglutination
• C. Immunofluorescence
• D. ELISA

Explanation: Radioimmunoassay is highly sensitive and specific for detecting very small amounts of hCG, making it the traditional gold-standard method.

• A. Sertoli cells
• B. Seminiferous tubules
• C. FSH
• D. Spermatogenesis

Explanation: Inhibin B is secreted mainly by Sertoli cells and selectively suppresses FSH release from the anterior pituitary.

• A. Testis but not ovaries
• B. Ovaries but not testis
• C. Adrenal cortex
• D. Both Testis and ovaries

Explanation: FSH and LH are gonadotropins, so they act on the gonads in both sexes. FSH primarily supports Sertoli cells and ovarian follicles, while…

• A. 14 days
• B. 28 days
• C. 8 weeks
• D. 1 week

Explanation: Implantation normally begins about 6 to 7 days after fertilization, when the blastocyst attaches to the endometrium.

• A. Estrogen
• B. Oxytocin
• C. Progesterone
• D. Prolactin

Explanation: Oxytocin contracts myoepithelial cells around the mammary alveoli, producing milk ejection or the let-down reflex.

• A. Myoepithelial cell contraction
• B. Milk ejection
• C. Contraction of uterine muscle
• D. Lactogenesis

Explanation: Oxytocin causes milk ejection by contracting mammary myoepithelial cells and also contracts uterine muscle.

• A. Gonadotropins increase , estrogens decrease
• B. Lh/FSH increase
• C. Estrogens and gonadotropins decrease
• D. Both increase

Explanation: At menopause, ovarian estrogen production falls, removing negative feedback on the pituitary; consequently FSH and LH rise.

• A. Prolactin
• B. L.H
• C. Testosterone
• D. Oxytocin

Explanation: Ovulation follows the mid-cycle luteinizing hormone surge, which triggers follicular rupture and release of the ovum.

• A. Enters the uterine cavity
• B. Penetrates corona radiate
• C. Comes in contact with zone pellucida
• D. Penetrates cell membrane of oocyte

Explanation: Contact and binding of sperm to receptors on the zona pellucida trigger the acrosome reaction, releasing enzymes that help the sperm…

• A. During intra - uterine life
• B. just before birth
• C. by around 6 years after birth
• D. by around 16 years

Explanation: Male germ cells remain in the premeiotic stage during fetal life and childhood; meiosis begins with spermatogenesis at puberty, commonly…

• A. 40 mm Hg
• B. 25 mm Hg
• C. 55 mm Hg
• D. 70 mm Hg

Explanation: Mixed venous blood has returned from the tissues after oxygen extraction, so its PO2 falls from the arterial value of about 95–100 mm Hg…

• A. Left
• B. Right
• C. Does not shift
• D. None of the above

Explanation: In the Haldane effect, oxygenation of haemoglobin in the lungs reduces its ability to carry CO2 and hydrogen ions, promoting CO2 release.

• A. Anemic
• B. Stagnant
• C. Hypoxic
• D. Histotoxic

Explanation: Hypoxic hypoxia is the commonest broad type and results from inadequate oxygenation of arterial blood, such as at high altitude or in lung…

• A. Stretching of airways
• B. Hypercapnia
• C. Acidosis
• D. Hypoxia

Explanation: Hypoxia, raised CO2 and acidosis stimulate ventilation through the respiratory control system.

• A. Anemia
• B. Pulmonary hypoventilation
• C. KCN poisoning
• D. CO poisoning

Explanation: Pulmonary hypoventilation reduces the amount of fresh air reaching alveoli, causing alveolar and arterial PO2 to fall while PCO2 rises.

• A. Fall in pH
• B. Rise in temperature
• C. HbF
• D. Increase of 2, 3 3 DPG

Explanation: A fall in pH, increased temperature and increased 2,3-DPG reduce haemoglobin’s oxygen affinity and shift the dissociation curve rightward.

• A. 2.5 lit/Min
• B. 4.0 lit /Min
• C. 9 Lit/Min
• D. 6.75 Lit/Min

Explanation: Alveolar ventilation equals (tidal volume − dead space) × respiratory rate. Thus, (600 − 150) × 15 = 6,750 ml/min, or 6.75 L/min.

• A. Increased by hyperventilation
• B. Decreased by hyperventilation
• C. Similar to venous O2 tension
• D. Not affected by respiratory depression

Explanation: Hyperventilation removes more CO₂ from the alveoli, and the alveolar gas equation therefore predicts a rise in alveolar PO₂.

• A. Pnemocyte I
• B. Pnemocyte II
• C. Goblet cells
• D. Pulmonary vessels

Explanation: Type II pneumocytes synthesize and release pulmonary surfactant, which lowers alveolar surface tension and helps prevent alveolar…