Question

Oxyntic cells secrete
(a) HCl
(b) Trypsin
(c) NaOH
(d) Pepsinogen

Answer 1

 Hint: Oxyntic cells secretes an inorganic chemical system that is a chloride- based system mixed with water essential for digestion and has a low pH. Along with other such similar chemicals, it forms gastric juices that break the long- chained amino acids forming the protein. This inorganic chemical is also used for creating PVC.

Complete Step by Step Answer: The epithelial cells which secrete hydrochloric acid (HCl) are oxyntic cells. These cells are found in the lining of the fundus and the cardia of the stomach in the gastric glands. They contain a vast secretory network from which HCl is secreted by active transport into the stomach (called canaliculi).
A canaliculus is a modification located on parietal gastric cells. It is a deep infolding, or narrow channel, which, for secretion, helps to increase the surface area.
In response to three kinds of stimuli, parietal cells secrete this acid: - Histamine activates the receptors of histamine ${ H }_{ 2 }$ (the most important contribution). - Acetylcholine, which activates ${ M }_{ 3 }$ receptors from parasympathetic activity through the vagus nerve and enteric nervous system. - Gastrin, ${ CCK }_{ 2 }$ receptor stimulator (least important contribution).
So, the answer is ‘HCl’.

Additional Information:
Due to over- acidity in the stomach, peptic ulcers may result. To increase the normal resistance of the gastric lining, antacids may be used. Acid secretion can be reduced by antimuscarinic drugs like pirenzepine or ${ H }_{ 2 }$ antihistamines. Proton pump inhibitors are more potent in reducing the production of gastric acid since it is the final popular pathway for all acid production stimulation.
Intrinsic factors are also produced by parietal cells. For vitamin ${ B }_{ 12 }$ absorption from the diet, the intrinsic factor is required. Long- term vitamin ${ B }_{ 12 }$ deficiency can lead to megaloblastic anemia, characterized by large erythrocytes that are fragile. Pernicious anemia results from autoimmune disruption of parietal gastric cells, precluding intrinsic factor synthesis and, by extension, vitamin ${ B }_{ 12 }$ absorption. Pernicious anemia contributes to megaloblastic anemia as well.

Note: - Oxyntic cells are also known as Parietal cells or dilomorphous cells. - The enzyme potassium hydrogen ATPase (${ H }^{ + } $/(${ K }^{ + } $ ATPase) is unique to parietal cells and transports H+ against a gradient of concentration. - Oxyntic cells are also responsible for the secretion of Intrinsic factors. - Gastrin also induces local ECL cells to secrete histamine, which in turn signals parietal cells through stimulation of histamine release. - Gastrin itself does not affect the maximum secretion of histamine- stimulated gastric acid. - Atrophic gastritis can cause an inability to absorb ${ B }_{ 12 }$, especially in the elderly, which can lead to deficiencies such as decreased DNA synthesis in bone marrow as well as in nucleotide metabolism.