GIT and challenges (gut, liver) Flashcards
Which of the are correct regarding the cephalic, gastric and intestinal phases of gastric acid secretion?
A The activation of the vagus nerve stimulates the release of somatostatin which increases gastrin release
B Chyme stimulates release cholecystokinin, secretin and gastric inhibitory peptide to suppress gastric secretion and motility.
C Taste or smell sends signals to the medulla oblongata activating the parasympathetic nervous system
D Ingested food stimulates gastric activity by stretching the stomach and by gastric contents stimulating gastric mucosa.
E Low pH stimulates gastric secretion by triggering the enterogastric reflex.
B- chyme, C- taste and smell D- ingested food all correct
a- somastatin inhibits gastrin release
e -high pH/ alkaline is what stimulates gastrin secretion
what is the basic unit of a liver cell / microanatomy
liver cells are called hepatocytes. these are contained into hexagonal lobules
the centre of the lobule is the hepatic vein - blood away
the corners of the hexagon is the portal triad where the bile ducts, portal vein and hepatic artery move through the liver to the hepatic vein via the sinusoids
there are also kupfer cells which are macrophages specific to the liver
> bile ducts receive bile from the bile canaliculi
what is the link between the liver and The Doctor
liver can self renew/regenerate after damage from toxins or damage
can you name the important liver blood vessels?
also some basic facts about the liver
(gross anatomy)
hepatic artery supplies the oxygen 25% blood supply and the portal vein supplies the nutrients 75% blood supply which comes from the spleen stomach and intestine
hepatic vein takes away the de-oxygenated blood
its quite big ya know - foosball size and behind the ribs and upper right hand abdomen and there is the gall bladder with its bile ducts connected too
what can be some causes of AP
alcholol abuse - alcohol metabolites like palmitoleic acid
bile disease
> leads to calcium overload, loss of cellular ATP , necorsis and inflammasiton of pancreatic tissue
why does treatment of Pancreatic acinar cells with pyruvate help to protect against alcohol induced caclium overload?
provides a new source of ATP and restores energy supplies to cells so then prevents cellular necrosis
what types of cells make up the pancreas
pancreatic acinar cells (PAC) ~ 80%
duct cells
to secrete pancreatic juices and enzymes into the duodenum
what does the digestive juice contain? where is it stored?
digestive enzymes, ions, electrolytes, albumin, globulin
> digestive enzymes must be stored in INACTIVE form within secretory granules to be safe
what stimulates PACs?
CCK - stimulates to secrete juice into duct system to the duodenum
Ach - enables local calcium signalling to occur
why do the duct cells release bicarbonate?
in order to NEUTRALISE the pancreatic juices and control the pH
what stimulates the duct cells to secrete bicarbonate?
secretin - hormone is produced by S-cells in duodenum during intestinal phase
bind to receptor on duct cell activating cftr channel allowing HCO3 release into lumen
