All Free Physiology MCQs with Answers

• A. Bicarbonate secretion
• B. Augments the action of CCK
• C. Gastric secretion increase
• D. Contraction of pyloric sphincter

Explanation: Secretin stimulates bicarbonate-rich pancreatic secretion and potentiates CCK, while it inhibits gastric acid secretion.

• A. All of the above
• B. Gastrin
• C. Mucin
• D. Hcl

Explanation: Parietal cells secrete hydrochloric acid and intrinsic factor. Gastrin is produced by antral G cells, while mucin is mainly secreted by…

• A. Increased gastric secretion
• B. Increased pancreatic secretion
• C. Relax lower esophageal sphincter
• D. Causes GB contraction

Explanation: CCK stimulates pancreatic enzyme secretion and gallbladder contraction, and it can relax the lower oesophageal sphincter.

• A. Large intestine
• B. Small intestine
• C. Liver
• D. Stomach

Explanation: The small intestine is the principal site for absorption because its long length, folds, villi and microvilli provide a very large…

• A. Pepsinogen
• B. Hydrochloric acid
• C. Chymotrypsinogen
• D. All of the above

Explanation: Pancreatic acinar cells release chymotrypsinogen, an inactive protease precursor that is activated in the intestine.

• A. Salivary
• B. Lacrimal
• C. Sweat
• D. Gastric

Explanation: Gastric juice secretion is approximately 1.5 to 2 litres per day, generally exceeding salivary and lacrimal secretion; sweat varies…

• A. Bile salts
• B. Cholesterol
• C. A & B
• D. Bile pigments

Explanation: Bile acids are synthesized in the liver from cholesterol and are then conjugated to form bile salts.

• A. Hepatitis
• B. Cirrhosis
• C. Increased break down of red cells
• D. Obstruction of bile canaliculi

Explanation: Increased red-cell destruction produces excess bilirubin before the liver can conjugate it, causing unconjugated hyperbilirubinemia.

• A. Secretin
• B. Lipase
• C. Maltase
• D. Antibacterial substance

Explanation: Paneth cells at the base of intestinal crypts release antimicrobial substances such as defensins and lysozyme, helping control intestinal…

• A. 3.5 seconds
• B. 9.5 seconds
• C. 6.0 seconds
• D. 1-1.5 seconds

Explanation: The oral and pharyngeal phases together propel the bolus rapidly and usually take about 1 to 1.5 seconds.

• A. Submucosa
• B. Lamina propria
• C. Muscularis
• D. Serosa

Explanation: Most diffuse GALT is found in the lamina propria, where lymphocytes, plasma cells, and other immune cells monitor intestinal contents.

• A. Heme
• B. Biliverdin
• C. Stercobilin
• D. Bilirubin diglucuronide

Explanation: Intestinal bacteria convert bilirubin derivatives into stercobilin, the pigment responsible for the normal brown colour of stool.

• A. sensory stimulation
• B. Sympathetic stimulation
• C. CNS stimulation
• D. Parasympathetic stimulation

Explanation: Parasympathetic stimulation produces a copious, watery secretion from the salivary glands.

• A. Contraction of skeletal muscle
• B. Decrease of heart rate
• C. Secretion of saliva
• D. Contraction of pupils

Explanation: Acetylcholine acting on nicotinic receptors at the neuromuscular junction produces an end-plate potential that triggers skeletal-muscle…

• A. Inhibitory post synaptic potential
• B. Action potential
• C. Miniature end plate potential
• D. End plate potential

Explanation: Spontaneous release of a single small packet, or quantum, of acetylcholine at rest produces a miniature end-plate potential.

• A. Net current in an outward direction
• B. Cell interior becomes more negative
• C. None of the above
• D. Cell interior becomes less negative

Explanation: The upstroke results mainly from rapid Na+ entry, making the cell interior progressively less negative and then positive.

• A. Voltage inactivation of the Na+ channel
• B. Depletion of intracellular Na+
• C. Inactivation of Na+ k+ ATPase
• D. Insufficient neurotransmitter

Explanation: During the absolute refractory period, voltage-gated Na+ channels are inactivated and cannot reopen immediately, regardless of stimulus…

• A. Adaptation
• B. Accommodation
• C. Refractoriness
• D. Electrotonus

Explanation: Accommodation is the rise in threshold when a slowly increasing, subthreshold stimulus is applied.

• A. Extraocular muscles
• B. Pharyngeal muscles
• C. Muscles of middle ear
• D. Laryngeal muscles

Explanation: The smallest motor units are found where precise, fine control is required, especially in laryngeal muscles.

• A. Depolarizing the motor end plate of skeletal muscle
• B. Inhibiting the CNS
• C. Inhibiting cholinesterase
• D. Blocking the release of acetyl choline at the end plate

Explanation: Succinylcholine persistently activates nicotinic receptors at the motor end plate, causing depolarization followed by inability to…