Biology · Science General

Human Digestive System

2,002 Questions

The human digestive system explores the breakdown of biomacromolecules, covering organs from the stomach to the small intestine. It involves physiological processes like chyme movement, pH levels, and nutrient absorption in the gut. These fundamental biology concepts are regularly featured in medical and general science competitive exams.

Small intestine functionsBiomacromolecule breakdownStomach and digestionIntestinal bacteria

Human Digestive System Questions

Multiple choice

Which hormone is secreted in response to acidic chyme from the stomach?

  1. Gastrin

  2. Secretin

  3. Cholecystokinin

  4. Gastric inhibitory peptide

  5. Ghrelin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Glands in the duodenum or small intestine secrete several hormones including secretin, cholecystokinin (CCK) and gastric inhibitory peptide (GIP). Secretin is a hormone secreted by the duodenal and jejunal mucosa when acid chyme enters the intestine. It stimulates secretion of pancreatic juice and to a lesser extent bile and intestinal secretion.

Multiple choice

Which of these is an iron binding salivary protein giving support to our immune system?

  1. Lipase

  2. Lysozyme

  3. Amylase

  4. Lactoferrin

  5. RNase
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lactoferrin (LF) also known as lactotransferrin (LTF) is a multifunctional protein of the transferrin family. It is a globular glycoprotein widely represented in various secretory fluids such as milk, saliva, tears and nasal secretions. It is folded into two globular units, each capable of binding up to 1.4 mg iron/g of protein. Lactoferrin is one of the components of the immune system of the body. It has antimicrobial activity (bacteriocide, fungicide) and is part of the innate defense mainly at mucoses.

Multiple choice

Which of the given substances can cause contraction of the gall bladder?

  1. Choleretics

  2. Secretin

  3. Micelles

  4. Bilirubin

  5. Cholecystokinin
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Cholecystokinin (CCK), formerly called pancreozymin, is a digestive hormone released with secretin when food from the stomach reaches the first part of the small intestine (duodenum). It is the major hormone responsible for gallbladder contraction and pancreatic enzyme secretion.

Multiple choice

Which of the following may be the reason for steatorrhoea?

  1. Acute inflammation in the pancreas gland

  2. Deficiency of pancreatic enzymes

  3. Infection of gastro intestinal tract

  4. Repeated loose motion

  5. Rapid movement of fecal matter through intestine
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Steatorrhoea is a condition characterized by an increase in fat content in stools leading to the production of pale, bulky, offensive and loose stools. The underlying cause is a defect or alteration in the functioning of the digestive system. The pancreas makes enzymes involved indigesting food, so its damage means fewer enzymes are produced. Since pancreatic enzymes are particularly responsible for digestion of fat, fewer enzymes means less fat is digested. Fat tends to remain in the stools making them paler, more foul smelling than usual and difficult to remove by flushing.

Multiple choice

Concerning the control of gastric secretion in humans, which of the following statements is correct?

  1. Secretin, released by the duodenum stimulates gastric secretion in the stomach.

  2. Parietal cells of the gastric glands secrete gastric acid in response to hormonal stimulation.

  3. Acid and pepsinogen is released by the stomach during the intestinal phase of gastric secretion.

  4. Gastric secretion does not commence unless the bolus reaches the stomach of an individual.

  5. The most abundant epithelial cells are gastric acid secreting cells.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Parietal cells produce gastric acid, a strong acid, that helps to break down food. These cells produce gastric enzymes, such as pepsinogen and lipase which help us to digest.