Physiology MCQs 2026

The primary stimulus for erythropoietin release is

1. Ahyperglycemia✓
2. Bhypoxia detected by the kidney✓
3. Chypercalcemia✓
4. Dhypernatremia✓

Calcium homeostasis is regulated mainly by

1. Ainsulin and glucagon only✓
2. BTSH and thyroxine only✓
3. CACTH and cortisol only✓
4. Dparathyroid hormone, calcitonin and vitamin D✓

The action potential in a neuron is propagated along the

1. Adendrites only✓
2. Baxon✓
3. Ccell body only✓
4. Dsynaptic cleft only✓

The neuromuscular junction uses which neurotransmitter

1. Adopamine✓
2. Bacetylcholine✓
3. Cserotonin✓
4. DGABA✓

Starling law of the heart states that

1. Aheart rate always equals stroke volume✓
2. Bafterload has no effect on output✓
3. Cstroke volume increases with increased venous return (preload)✓
4. Dcontractility is fixed✓

The glomerular filtration rate is primarily autoregulated by

1. Aafferent and efferent arteriolar tone✓
2. Bureter peristalsis✓
3. Cbladder compliance✓
4. DADH levels alone✓

Body temperature is regulated by the

1. Acerebellum✓
2. Bhypothalamus✓
3. Cmedulla oblongata only for all thermoregulation✓
4. Doccipital lobe✓

The Bohr effect describes

1. Aincreased oxygen binding in acidosis✓
2. Bcarbon monoxide binding preference only✓
3. Cchloride shift in platelets✓
4. Ddecreased hemoglobin oxygen affinity with increased CO2 and acidity✓

Renin is secreted by the

1. Aadrenal medulla✓
2. Bposterior pituitary✓
3. Cjuxtaglomerular cells of the kidney✓
4. Dliver hepatocytes✓

The Frank-Starling mechanism improves cardiac output during exercise by

1. Adecreased heart rate only✓
2. Bdecreased preload✓
3. Cincreased venous return stretching the ventricle✓
4. Dcomplete AV block✓

Primary active transport example in physiology is

1. Asodium-potassium ATPase pump✓
2. Bfacilitated diffusion of glucose✓
3. Csimple diffusion of oxygen✓
4. Dosmosis of water✓

The Haldane effect refers to

1. Aoxygen increasing CO2 carrying capacity✓
2. Bnitrogen dissolving in plasma only✓
3. Cdeoxygenated hemoglobin carrying more CO2✓
4. Dchloride binding to hemoglobin only in lungs✓

Baroreceptors in the carotid sinus respond to

1. Ablood glucose levels✓
2. Bchanges in arterial blood pressure✓
3. Cpartial pressure of oxygen in alveoli only✓
4. DCSF pressure✓

The main buffer system in extracellular fluid is

1. Aphosphate only✓
2. Bhemoglobin only in plasma✓
3. Cbicarbonate-carbonic acid✓
4. Dprotein buffers only without bicarbonate✓

Normal adult resting heart rate is approximately

1. A120-160 beats per minute✓
2. B30-40 beats per minute✓
3. C100-140 beats per minute always✓
4. D60-100 beats per minute✓

The pacemaker of the heart is the

1. Aatrioventricular node only✓
2. Bsinoatrial node✓
3. Cbundle of His only✓
4. DPurkinje fibers only✓

Oxygen is primarily transported in blood bound to

1. Aplasma albumin only✓
2. Bwhite blood cells✓
3. Chemoglobin in red blood cells✓
4. Dplatelets✓

Insulin is secreted by

1. Abeta cells of the pancreatic islets✓
2. Balpha cells of pancreas✓
3. Cdelta cells only✓
4. Dadrenal cortex✓

Glucagon acts to

1. Alower blood glucose✓
2. Bincrease insulin secretion directly✓
3. Cblock renal glucose reabsorption✓
4. Draise blood glucose by glycogenolysis and gluconeogenesis✓

The primary function of aldosterone is

1. Awater reabsorption via ADH only✓
2. Bcalcium absorption in gut only✓
3. Csodium reabsorption and potassium excretion in the kidney✓
4. Dred blood cell production✓

Antidiuretic hormone (ADH) increases

1. Asodium excretion only✓
2. Bpotassium retention only✓
3. Cglucose filtration✓
4. Dwater reabsorption in the collecting duct✓

The normal pH of arterial blood is approximately

1. A7.35-7.45✓
2. B6.8-7.0✓
3. C7.6-7.8✓
4. D8.0-8.2✓

Surfactant in the lungs reduces

1. Amucus production only✓
2. Bbronchial smooth muscle tone only✓
3. Cpulmonary blood flow✓
4. Dsurface tension to prevent alveolar collapse✓

The refractory period in cardiac muscle prevents

1. Atetanic contraction of the heart✓
2. Bnormal sinus rhythm✓
3. Catrial contraction✓
4. Dventricular filling✓

Gastrointestinal motility is coordinated by the

1. Aenteric nervous system and hormones✓
2. Bsympathetic system alone✓
3. Ccerebellum alone✓
4. Dreticular activating system alone✓