Exams › NEET › Biology

Crypts of Lieberkuhn are tubular glands that lie between the finger-like projections of the inner surface of the small intestine. Glisson’s capsule is a layer of connective tissue present in liver. Islets of Langerhans constitute the endocrine portion of pancreas and are responsible for the production and release of hormones that regulate glucose levels. Brunner’s glands are found in submucosa of duodenum and protect the intestinal walls from gastric juices.

1. Argentaffin cells are identified with the production of serotonin (5-hydroxytryptamine), which is secreted into the lamina propria rather than the intestinal lumen.
2. Serotonin is a powerful stimulant of smooth muscle, resulting in contraction, and may play a role in stimulating peristaltic activity of the intestine.
3. Rennin and Pepsin enzymes are present in the gastric juice whereas Maltase is present in the intestinal juice.
4. The main constituent of gastric acid is hydrochloric acid which is produced by parietal cells (also called oxyntic cells) in the gastric glands in the stomach.

Correct answer: The main constituent of gastric acid is hydrochloric acid which is produced by parietal cells (also called oxyntic cells) in the gastric glands in the stomach.

Solution

The correct statement identifies the main acid in gastric juice as hydrochloric acid and correctly links its secretion to parietal (oxyntic) cells in the gastric glands. The other options describe intestinal hormones/enzymes or serotonin effects, not the primary acid-producing mechanism of the stomach.

Related NEET Biology questions

• Pepsin acts in
• lleum is characterised by the presence of
• Identify the correct statement with reference to human digestive system.
• Which cells of 'Crypts of Lieberkuhn' secrete antibacterial lysozyme?
• Which of the following statements is not correct?
• Which of the following guards the opening of hepatopancreatic duct into the duodenum?

⚔️ Practice NEET Biology free + battle 1v1 →