WEEK 8: 8.4 continued Flashcards
(28 cards)
What levels is the pancreas located in
L1, L2
From what structures does the pancreas span from
The duodenum to spleen
What kind of peritoneal is the pancreas?
retroperitoneal
Where does the splenic artery run across the pancreas
at the superior border
What kind of cells are predominantly in the pancreas?
acinar and duct cells
What are acinar and duct cells?
They are the exocrine portion of pancreas, secretions from these cells empty into the pancreatic duct
What are the exocrine secretions made by duct cells?
aqueous alkaline solution, which is sodium bicarbonate rich
What are the exocrine secretions made by acinar cells?
Pancreatic enzymes
What are the 3 pancreatic enzymes released by acinar cells, and a brief overview of their functions?
Proteolytic enzymes: protein digestion
Pancreatic amylase: carbohydrate digestion
Pancreatic lipase: fat digestion
What are the major pancreatic proteases?
trypsinogen
chymotrypsinogen
procarboxypeptidase
What are some protective mechanisms for trypsin
- enzymes are stored and released in inactive form
- trypsinogen is activated to trypsin by enterokinase
- pancreas produces trypsin inhibitor
-duodenum secretes mucus (physical barrier)
What does pancreatic amylase do?
it hydrolyses polysaccharides into maltose
What does pancreatic lipase do?
hydrolyses triglycerides into monoglycerides and free fatty acids.
What happens if there is pancreatic insufficiency and it doesn’t produce the 3 pancreatic enzymes
lipase doesn’t break down triglycerides, resulting in steatorrhoea, excess fat in faeces
What are the function of duct cells?
To neutralise chyme by secreting NaHCO3-
What is the optimal pH for pepsin?
low pH
What is trypsin?
neutral/alkaline pH
How does acid in the duodenal lumen ultimately neutralise itself?
acid in the duodenal lumen causes secretin release from duodenal mucosa, which increases sodium bicarbonate secreted by pancreatic duct cells into the duodenal lumen, hence ultimately neutralising the acid in the duodenal lumen
Explain the role of CKK in digesting fat and protein products in the duodenal lumen
CKK is released upon fat and protein being in the duodenum, which stimulates pancreatic acinar cells to secrete pancreatic digestive enzymes into duodenal lumen.
What are the functions of the liver?
- synthesis of molecules (eg. plasma proteins)
-synthesis of bile - metabolism, detoxification, inactivation of molecules
- storage and release of molecules like glucose
- endocrine function (modification of vit D and thyroid hormone)
What are the two surfaces of the liver?
diaphragmatic and visceral
Which organ receives the vast majority of venous return from the GIT
liver
What artery supplies the liver?
the hepatic artery
what vein drains into the liver?
hepatic portal vein from the gastrointestinal tract
