Physio Pre ICA Flashcards
(114 cards)
What does the lower oesophageal sphincter do?
It relaxes to accommodate the bolus.
It protects against gastroesophageal reflux.
What does the fundus of the stomach do?
It produces HCL, pepsinogen, intrinsic factor, and lipase.
What does the antrum of the stomach do?
It produces peptide hormone gastrin and is involved in the mixing and grinding of chyme
What does the parietal cells in the gastric gland secrete?
Acid and intrinsic factor.
What does the ECL cells in the gastric gland secrete?
Histamine.
What does the chief cells in the gastric gland secrete?
Pepsinogen.
After meal stimulation, what is the ionic change that happens in the gastric juice?
Increase in chloride and hydrogen ion. (HCL)
Decrease in potassium, sodium, and bicarbonate.
Hydrochloric acid is hypotonic or isotonic?
Isotonic.
The tubulo-vesicles of the parietal cell are stimulated by which hormones?
Acetylcholine and histamine.
What happens when the tubulo-vesicles fuse into secretory canaliculi?
They pump hydrochloric acid out of the cell and into the gastric gland/lumen of the stomach.
What does carbonic anhydrase release during parietal secretion?
It releases carbonic acid from water and carbon dioxide.
What happens when the carbonic acid dissociates during parietal secretion?
The hydrogen leaves in exchange for potassium.
The bicarbonate leaves, and the urine becomes alkaline because of the bicarbonate.
What does acetylcholine stimulate in motor neurones?
The release of pepsinogen from chief cells.
The release of histamine from ECL cells.
The release of HCL from parietal cells.
What does the cholinergic (GRP) stimulate during vagal outflow?
The release of gastrin from G cells.
What are the three factors that stimulate gastric secretion?
The hormone gastrin, Histamine, and acetylcholine.
From which type of cells is gastrin secreted?
Antral G cells.
When gastrin is secreted, how does it stimulate acid secretion?
Gastrin stimulates the release of histamine from ECL cells. Histamine stimulates acid secretion.
If the body wants to prevent overstimulation of gastric acid, which hormone does it produce?
Somatostatin.
Somatostatin comes from which type of cells?
D cells.
Somatostatin blocks which hormone?
It blocks the secretion of gastrin.
What happens when low antral pH is low?
Somatostatin is released.
What is glycoprotein mucin?
It is the most important part of mucus. It is hydrolysed by pepsin.
How is pepsin formed in the gastric juice?
Low pH causes the cleavage of pepsinogen into pepsin.
What is the importance of intrinsic factor?
It helps absorb vitamin B12.