Free Digestive System MCQs with Answers

• A. Duodenum, jejunum, ileum, colon
• B. Jejunum, duodenum, ileum, colon
• C. Ileum, jejunum, duodenum, colon
• D. Duodenum, ileum, jejunum, colon

Explanation: Food passes from the stomach into the duodenum, then through the jejunum and ileum before entering the colon.

• A. Breaking food into smaller pieces by chewing
• B. Changing starch into maltose by amylase
• C. Starting protein digestion with gastric enzymes
• D. Emulsifying fat with bile salts

Explanation: Chewing physically breaks food into smaller pieces and mixes it with saliva.

• A. Initial starch digestion and lubrication of food
• B. Protein digestion and absorption of vitamin B12
• C. Fat emulsification and storage of bile
• D. Water absorption and formation of faeces

Explanation: Saliva moistens food and contains salivary amylase, which begins starch digestion.

• A. Pyloric sphincter
• B. Cardiac sphincter
• C. Ileocecal valve
• D. Internal anal sphincter

Explanation: The pyloric sphincter regulates the emptying of partially digested food from the stomach into the duodenum.

• A. Bicarbonate
• B. Pepsin
• C. Intrinsic factor
• D. Hydrochloric acid

Explanation: Pancreatic bicarbonate neutralizes acid entering the duodenum from the stomach.

• A. Transport of digested fats into lymphatic vessels
• B. Transport of amino acids into blood capillaries
• C. Absorption of water into the colon
• D. Movement of glucose into the stomach

Explanation: Lacteals are lymphatic vessels inside intestinal villi that take up most absorbed fats as chylomicrons.

• A. My body uses absorbed nutrients in its cells
• B. My stomach breaks food into smaller molecules
• C. My intestine moves nutrients into the blood
• D. My rectum stores waste before elimination

Explanation: Assimilation is the use of absorbed nutrients by body cells for energy, growth, repair, or storage.

• A. Poor chemical digestion of triglycerides
• B. Failure to begin starch digestion in the mouth
• C. Reduced breakdown of proteins in the stomach
• D. Failure to absorb vitamin B12 in the ileum

Explanation: Pancreatic lipase chemically breaks triglycerides into absorbable fatty acids and monoglycerides.

• A. Duodenum
• B. Oesophagus
• C. Rectum
• D. Sigmoid colon

Explanation: The duodenum receives bile from the biliary tract and pancreatic secretions through ducts.

• A. Rhythmic peristaltic contractions push the contents onward
• B. The villi pull food directly into the bloodstream
• C. Bile causes the intestine to contract as one solid tube
• D. The pancreas pumps food through the intestinal wall

Explanation: Peristalsis consists of coordinated waves of smooth muscle contraction that propel contents through the alimentary canal.

• A. Mucosa
• B. Submucosa
• C. Muscularis externa
• D. Serosa

Explanation: The muscularis externa contains inner circular and outer longitudinal smooth muscle layers that move and mix intestinal contents.

• A. Chief cells
• B. Parietal cells
• C. G cells
• D. Goblet cells

Explanation: Parietal cells secrete hydrochloric acid and intrinsic factor. Chief cells produce pepsinogen, G cells release gastrin, and goblet cells…

• A. Secretin
• B. Gastrin
• C. Cholecystokinin
• D. Somatostatin

Explanation: Cholecystokinin, or CCK, is released mainly in response to fats and amino acids in the duodenum.

• A. Pyloric sphincter
• B. Ileocecal valve
• C. Anal sphincter
• D. Lower oesophageal sphincter

Explanation: The ileocecal valve lies between the ileum and caecum and helps prevent reflux of colonic contents into the small intestine.

• A. Hydrochloric acid
• B. Intrinsic factor
• C. Gastrin
• D. Mucus

Explanation: Intrinsic factor is needed for vitamin B12 absorption in the terminal ileum.

• A. Trypsin
• B. Pancreatic amylase
• C. Pancreatic lipase
• D. Nuclease

Explanation: Enterokinase, also called enteropeptidase, activates trypsinogen to trypsin in the duodenum.

• A. Caecum
• B. Sigmoid colon
• C. Rectum
• D. Anal canal

Explanation: The rectum temporarily stores faeces before defecation. The sigmoid colon transports faecal material toward the rectum, and the anal canal…

• A. Soft palate
• B. Uvula
• C. Epiglottis
• D. Vocal cord

Explanation: The epiglottis moves over the laryngeal opening during swallowing and helps direct food into the oesophagus.

• A. Rapid emptying of the stomach
• B. Delayed movement into the duodenum
• C. Backflow from the colon into the ileum
• D. Loss of bile production by the liver

Explanation: The pyloric sphincter regulates the passage of chyme from the stomach into the duodenum.

• A. Duodenum
• B. Jejunum
• C. Ileum
• D. Caecum

Explanation: The duodenum is the first part of the small intestine and receives gastric chyme, bile, and pancreatic juice.