What are the secretions of the parietal cells?
The parietal cells are located in the middle part of the glands of the fundus-body region of the stomach. They secrete gastric acid, i.e. hydrochloric acid (approximately 0.16 M, pH ≥ 0.8) and secrete the intrinsic factor, which is a vitamin B12-binding protein.
What receptors are on parietal cells?
Four types of receptors have so far been identified on the parietal cell: receptors for gastrin, acetylcholine, and histamine, whose activation leads to stimulation of acid secretion, and receptors for prostaglandins of the E series, whose activation leads to inhibition of acid secretion.
What do parietal cells produce and secrete?
Parietal cells (also known as oxyntic cells) are epithelial cells in the stomach that secrete hydrochloric acid (HCl) and intrinsic factor. These cells are located in the gastric glands found in the lining of the fundus and body regions of the stomach.
What do ECL cells secrete?
The enterochromaffin-like (ECL) cells of the oxyntic mucosa (fundus) of the stomach produce, store and secrete histamine, chromogranin A-derived peptides such as pancreastatin, and an unanticipated but as yet unidentified peptide hormone.
Do parietal cells secrete bicarbonate?
These cells secrete a bicarbonate-rich mucus that coats and lubricates the gastric surface, and serves an important role in protecting the epithelium from acid and other chemical insults. Acid: Hydrochloric acid is secreted from parietal cells into the lumen where it establishes an extremely acidic environment.
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.
What does cAMP do in parietal cells?
The major path for parietal cell stimulation is via H2-receptor-mediated adenylate cyclase and elevation of cAMP to activate protein kinase A (PKA), which phosphorylates key effector proteins, e.g., ezrin, a membrane-cytoskeletal linker, apical Cl- or K(+)-channels.
What stimulates parietal cells to secrete HCl?
Histamine
Histamine stimulates the parietal cells to secrete HCl.
How do parietal cells produce HCl?
Are ECL cells parietal cells?
Enterochromaffin-like cells or ECL cells are a type of neuroendocrine cell found in the gastric glands of the gastric mucosa beneath the epithelium, in particular in the vicinity of parietal cells, that aid in the production of gastric acid via the release of histamine.
What do Argentaffin cells secrete?
An argentaffin cell is any enteroendocrine cell, a hormone-secreting cell present throughout the digestive tract. It is a property of melanin, and special stain can be applied to identify those granules.
How do parietal cells secrete HCl?
Hydrochloric Acid Production HCl is produced by the parietal cells of the stomach. To begin with, water (H2O) and carbon dioxide (CO2) combine within the parietal cell cytoplasm to produce carbonic acid (H2CO3), which is catalysed by carbonic anhydrase.