Digestion and absorption - human alimentary canal and digestive glands - Question Bank

1. The liver receives blood from the hepatic artery and the hepatic portal vein. The hepatic portal vein carries blood rich in absorbed nutrients from the:
A) Stomach and oesophagus
B) Small intestine, large intestine, stomach, and spleen
C) Heart and lungs
D) Kidneys and bladder
2. The absorption of certain electrolytes and minerals, like iron and calcium, is an active process occurring mainly in the:
A) Stomach
B) Duodenum and jejunum
C) Ileum
D) Large intestine
3. The enzyme lactase, found in the intestinal juice, breaks down lactose into:
A) Glucose and glucose
B) Glucose and galactose
C) Galactose and fructose
D) Two molecules of lactose
4. Which part of the small intestine is mainly responsible for the absorption of vitamin B12 and bile salts?
A) Duodenum
B) Jejunum
C) Ileum
D) Colon
5. The process of breaking down food into absorbable units is called digestion, while the process of moving these units from the lumen of the intestine into the blood or lymph is called:
A) Ingestion
B) Egestion
C) Absorption
D) Assimilation
6. The muscular sphincter that regulates the exit of feces from the body is the:
A) Pyloric sphincter
B) Internal anal sphincter
C) External anal sphincter
D) Both internal and external anal sphincters
7. The rectum is the final section of the large intestine, terminating at the:
A) Caecum
B) Colon
C) Anus
D) Sigmoid colon
8. The primary role of the caecum in humans is:
A) Digestion of cellulose
B) Absorption of water
C) Storage of feces
D) Fermentation of indigestible material
9. The vermiform appendix is a small, finger-like outgrowth attached to the:
A) Stomach
B) Jejunum
C) Caecum
D) Rectum
10. Cholecystokinin (CCK) stimulates the gall bladder to contract and release bile, and also stimulates the pancreas to release:
A) Bicarbonate ions
B) Enzyme-rich pancreatic juice
C) Insulin
D) Glucagon
11. The hormone secretin primarily stimulates the pancreas to release:
A) Enzymes
B) Bicarbonate-rich pancreatic juice
C) Bile
D) Hydrochloric acid
12. Which hormone stimulates the secretion of gastric juice from the stomach wall?
A) Secretin
B) Cholecystokinin
C) Gastrin
D) Enterogastrone
13. The structure that controls the opening of the stomach into the duodenum is the:
A) Pyloric sphincter
B) Oesophageal sphincter
C) Ileocecal valve
D) Anal sphincter
14. The final stage of digestion involves the elimination of indigestible food material through the anus, a process called:
A) Absorption
B) Assimilation
C) Egestion
D) Secretion
15. The large intestine primarily absorbs:
A) Most of the nutrients
B) Water and electrolytes
C) All digested food
D) Vitamins synthesized by bacteria
16. Water-soluble vitamins (B complex and C) are absorbed by:
A) Facilitated diffusion or active transport
B) Simple diffusion
C) Pinocytosis
D) Endocytosis
17. Fat-soluble vitamins (A, D, E, K) are absorbed along with:
A) Water
B) Minerals
C) Fats
D) Proteins
18. The absorption of digested fats, mainly in the form of fatty acids and glycerol, involves their re-esterification into triglycerides within the intestinal cells and packaging into lipoprotein particles called:
A) Chylomicrons
B) Micelles
C) VLDL
D) HDL
19. Absorption of simple sugars and amino acids primarily occurs in the:
A) Stomach
B) Duodenum and jejunum
C) Ileum
D) Large intestine
20. Fats are digested by lipases into:
A) Glucose and fructose
B) Amino acids
C) Fatty acids and glycerol
D) Nucleotides
21. The final products of protein digestion are:
A) Monosaccharides
B) Fatty acids and glycerol
C) Amino acids
D) Nucleosides
22. The final products of carbohydrate digestion are:
A) Amino acids
B) Fatty acids and glycerol
C) Monosaccharides (e.g., glucose, fructose)
D) Nucleotides
23. The intestinal juice, also known as succus entericus, is secreted by the glands in the intestinal wall and contains enzymes that complete the digestion of:
A) Proteins and carbohydrates
B) Fats and carbohydrates
C) Proteins, carbohydrates, and fats
D) Only nucleic acids
24. Pancreatic juice contains enzymes like amylase, lipase, and proteases (e.g., trypsinogen, chymotrypsinogen). Trypsinogen is activated to trypsin by an enzyme secreted by the intestinal mucosa called:
A) Enterokinase
B) Secretin
C) Cholecystokinin
D) Enterocrinin
25. The pancreas is a gland that secretes both exocrine (digestive enzymes) and endocrine (hormones) substances. Its exocrine function involves secreting:
A) Insulin and glucagon
B) Pancreatic juice containing various enzymes
C) Bile
D) Hydrochloric acid
26. Bile plays a crucial role in fat digestion by:
A) Breaking down fats into fatty acids and glycerol
B) Activating lipase enzymes
C) Emulsifying fats into smaller droplets
D) Absorbing fat-soluble vitamins
27. The liver produces bile, which is stored and concentrated in the:
A) Pancreas
B) Gall bladder
C) Spleen
D) Appendix
28. Which of the following digestive glands is the largest gland in the body?
A) Pancreas
B) Salivary glands
C) Liver
D) Gastric glands
29. Each villus in the small intestine contains a network of capillaries and a large lymphatic vessel called a:
A) Sinusoid
B) Lacteal
C) Capillary bed
D) Venule
30. The inner lining of the small intestine is characterized by numerous finger-like projections called villi and microvilli, which:
A) Secrete digestive enzymes
B) Propel food forward
C) Greatly increase the surface area for absorption
D) Neutralize stomach acid
31. The first part of the small intestine, which receives chyme from the stomach and bile and pancreatic juice from the liver and pancreas, is the:
A) Jejunum
B) Ileum
C) Duodenum
D) Caecum
32. The small intestine is the principal site for the completion of digestion and the primary site for the absorption of nutrients. It is divided into three parts: duodenum, jejunum, and:
A) Ileum
B) Colon
C) Rectum
D) Caecum
33. The semi-digested food mixture that leaves the stomach and enters the small intestine is called:
A) Bolus
B) Chyme
C) Feces
D) Micelles
34. Hydrochloric acid (HCl) in the stomach serves multiple functions, including:
A) Emulsifying fats
B) Activating pepsinogen and killing microbes
C) Breaking down carbohydrates
D) Neutralizing acidic chyme
35. Pepsinogen, an inactive enzyme precursor, is converted to its active form, pepsin, by:
A) Bile salts
B) Hydrochloric acid
C) Secretin
D) Enterokinase
36. Gastric juice is secreted by glands in the stomach wall. The main enzyme responsible for protein digestion in the stomach is:
A) Trypsinogen
B) Pepsin
C) Chymotrypsin
D) Carboxypeptidase
37. The innermost lining of the stomach contains folds called rugae, which:
A) Increase surface area for absorption
B) Allow the stomach to expand
C) Secrete gastric juices
D) Protect the stomach wall from acid
38. The stomach is a J-shaped organ located in the upper part of the abdomen, primarily responsible for:
A) Absorption of water
B) Digestion of proteins
C) Storage and initial digestion of food
D) Secretion of bile
39. The movement of food through the oesophagus and other parts of the alimentary canal is facilitated by wave-like muscular contractions known as:
A) Segmentation
B) Peristalsis
C) Mass movements
D) Churning
40. The oesophagus is a muscular tube that connects the pharynx to the:
A) Duodenum
B) Stomach
C) Small intestine
D) Large intestine
41. The flap of cartilage that prevents the entry of food into the trachea during swallowing is called the:
A) Glottis
B) Epiglottis
C) Larynx
D) Pharynx
42. The muscular walls of the pharynx play a role in:
A) Mechanical digestion
B) Chemical digestion
C) Swallowing (deglutition)
D) Absorption of nutrients
43. The tongue is a muscular organ that helps in:
A) Swallowing and tasting food
B) Mixing food with saliva and swallowing
C) Chewing and tasting food
D) Digesting carbohydrates
44. Salivary amylase, also known as ptyalin, breaks down starch into:
A) Glucose
B) Fructose
C) Maltose
D) Lactose
45. The enzyme present in saliva that begins the chemical digestion of carbohydrates is:
A) Pepsin
B) Trypsin
C) Amylase
D) Lipase
46. Saliva is secreted by three pairs of salivary glands. Which of these is located just in front of the ear?
A) Sublingual gland
B) Submandibular gland
C) Parotid gland
D) Palatine gland
47. The main function of mastication (chewing) in the mouth is to:
A) Sterilize food particles
B) Break down food mechanically
C) Increase the surface area for enzyme action
D) Dissolve food particles in saliva
48. The alimentary canal begins with the anterior opening, the:
A) Anus
B) Mouth
C) Pharynx
D) Oesophagus
49. Which of the following is the primary function of the human alimentary canal?
A) Circulation of blood
B) Digestion and absorption of food
C) Excretion of metabolic waste
D) Regulation of body temperature
50. The process of breaking down complex food substances into simpler, absorbable forms is called:
A) Ingestion
B) Digestion
C) Absorption
D) Egestion