Liver and friends Flashcards
give 3 purposes of the aqueous (HCO3- rich) secretion by the parcreas
buffer the duodenum against acid entering it from the stomach and providing a suitable pH for the action of enzymes in the intestine, the low pH also stops the action of pepsin from the stomach
what electrolytes’ concentrations are relatively constant in the pancreatic juices?
Na+ and k+
in a high flow rate, is the pancreatic juice high in Hco3- or cl-?
HCO3-
what blood vessel does the pancreas mainly receive its blood supply from?
the splenic artery
which bud of the pancreas is the one that rotates in its development to fuse with the other
the ventral bud
Santorini’s duct forms what duct of the pancreas and is it part of the ventral or dorsal bud to start with?
the accessory duct. the dorsal bud
at what week in utero do the ventral and dorsal buds of the pancreas form?
week 5
what is the common bile duct a fusion of?
the pancreatic duct and bile duct
what type of muscle surrounds the sphincter of Oddie?
circular smooth muscle
is the minor papilla above or below the major papilla?
above
what is the main exocrine tissue of the pancreas called?
the acinar tissue
histologically, is the pancreatic endocrine or exocrine tissue usually lighter in colour?
endocrine
what cells in the pancreas produce and secrete the enzymes eg trypsinogen? so do they appear darker or lighter histologically due to them being protein rich?
the acinar cells. they appear darker
what cells of the pancreas secrete bicarbonate?
the centro-acinar cells
what does simulation of the bicarbonate-releasing duct cell of the pancreas result in an increase of?
intracellular cyclic AMP.
what 2 things does the increase in cAMP in the duct cells of the pancreas cause?
- movement of tubulovesicles that contain H+ pumps to move to the basolateral membrane
- dis-aggregation and activation of CFTR
what moves out of the basolateral membrane of the pancreatic duct cell and via what?
H+ via the H+ pumps that were contained in tubulovescicles by active transport
what ion is exchanged for HCO3- at the apical membrane of the duct cell of the pancreas via CFTR
cl-
what enzyme catalyses the formation of h2co3 and vice versa from carbon dioxide and water in the pancreas duct cell
carbonic anhydrase
other than providing hco3- substrate for the transport out via the apical membrane what is another benefit of forming h2co3 within the duct cell of the pancreas
maintaining a concentration gradient for the continuous movement of water and carbon dioxide into the duct cell
what hormone stimualtes Hco3- secretion in the pancreas?
secretin
what hormone stimulates enzymatic production and secretion in the pancreas and is produced in the duodenum?
CCK
what paracrine agent is produced in the pancretic islets, by delta cells and stops exocrine secretion by the pancreas?
somatostatin
what receptors do CCK and gastrin bind to in the pancreas to stimulate exocrine secretion
CCK A receptors
what receptors do secretin and VIP bind to in the pancreas
VIP receptors
what 2 enzymes can activate all other zymogens once in the intestine
trypsin and enterokinase
what is the zymogen equivalent of elastase
proelastase
what is the zyogen to carboxypeptidase
pro-carboxypeptidase
what cells is enterokinase in? what type of enzyme is it?
enterocytes. a proteolytic enzyme
what 2 enzymes are already secreted in the active form from the pancreas?
amylase and lipase
other than the intestinal phase that causes secretions from the pancreas to increase what 2 stimuli from the gastric and cephalic phase also cause increased pancreatic secretion?
vagal cholinegics from the cephalic phase and stimulation of the G cells of the stomach to produce gastrin by the vagus nerve and the gastrin causes the acinar cells to release enzymes and the duct cells to secret electrolytes, this is the gastric phase
what sort of stimuli mediate the gastric phase?
swallowing of food and hypoglycaemia
what is involved in the intestinal phase to cause secretion of bicarbonate from the duct cells
increased acidity, fatty acids and amino acids in the duodenum stimulates the S cells of the stomach to secrete secretin and the secretion of CCK by enteroendocrine cells (specifically L cells) and so the duct and acinar cells are stimulated to release enzymes and bicarbonate and water
what are the 2 surfaces of the liver
diaphragmatic and visceral
what are the 2 recesses on the diaphragmatic surface of the liver
subphrenic recess and hepatorenal recess (between the liver and the right kidney and suprarenal gland
what is the left triangular ligament of the liver formed of
the falciform ligament and ligamentum venosum
what does the falciform ligament attach the liver to?
the anterior abdominal wall (the diaphragm)
what is at the colic impression of the liver?
the right hepatic flexure of the colon (start of the transverse colon