How is HCl secreted?

When stimulated, parietal cells secrete HCl at a concentration of roughly 160 mM (equivalent to a pH of 0.8). The acid is secreted into large cannaliculi, deep invaginations of the plasma membrane which are continuous with the lumen of the stomach.

Where HCl is secreted?

the stomach
The active components of gastric acid are protons and chloride. Often simplistically described as hydrochloric acid, these species are produced by parietal cells in the gastric glands in the stomach. The secretion is a complex and relatively energetically expensive process.

What stimulates HCl secretion?

Histamine stimulates the parietal cells to secrete HCl.

What causes HCl secretion in stomach?

Acid secretion is initiated by food: the thought, smell, or taste of food effects vagal stimulation of the gastrin-secreting G cells located in the distal one third (antrum) of the stomach. The arrival of protein to the stomach further stimulates gastrin output.

How is HCl secreted by parietal cells?

The tight regulation of parietal cells ensures the proper secretion of HCl. The H+-K+-ATPase enzyme expressed in parietal cells regulates the exchange of cytoplasmic H+ for extracellular K+. The H+ secreted into the gastric lumen by the H+-K+-ATPase combines with luminal Cl- to form gastric acid, HCl.

How gastric acid is secreted?

Basic mechanisms controlling gastric acid secretion. Somatostatin secreted from gastric D cells modulates the gastrin-enterochromaffin-like (ECL) cell–parietal cell axis. Gastrin, secreted from G cells, stimulates the release of histamine from ECL cells, which is the major stimulant of acid from gastric parietal cells.

What inhibits HCl secretion?

Summary. Histamine H2-receptor antagonists and proton pump inhibitors are the main classes of drug used to inhibit gastric acid secretion.

What happens if HCl is not secreted in stomach?

Q. Assertion :If HCl is not secreted, digestion of proteins in the stomach will be impaired. Reason: Acidic pH is required for function of pepsin and renin.

What is the role of HCl in digestion?

Hydrochloric acid contributes to protein digestion by supplying H+ which activates pepsinogen, the precursor to pepsin. Pepsinogen is secreted by chief cells in the gastric glands of the body and antrum of the stomach.

How is gastric acid secreted?

Acid is secreted by parietal cells in the proximal two thirds (body) of the stomach. Gastric acid aids digestion by creating the optimal pH for pepsin and gastric lipase and by stimulating pancreatic bicarbonate secretion.

What are the 3 phases of gastric secretion?

The physiologic stimulation of acid secretion has classically been divided into three interrelated phases: cephalic, gastric, and intestinal [2]. The cephalic phase is activated by the thought, taste, smell, and sight of food, and swallowing.