Digestion and Absorption Flashcards
Name two cell types you can find in the pancreas
Acinar cells and duct cells
What do pancreatic duct cells do?
. Produce enzyme-rich secretion and aqueous alkaline secretion
. Exchange bicarbonate for chloride (uptake chloride, secrete HCO3- for digestion, favouring alkaline enzymes further down GI tract)
What is different about the structure of pancreatic duct cells in those with cystic fibrosis? What impact does this have on digestion and absorption?
People with CF lack chloride ion channels in their pancreatic duct cells, so can’t exchange Cl- for HCO3- and thus have malabsorption because they can’t digest food properly
How are monosaccharides transferred from the gut lumen to the blood?
Via sodium co-transporters
What does trypsin do?
Activates peptidases in duodenum and on brush border epithelia
How is secretin activated and what does it do?
Activated by acid in duodenum, stimulates release of HCO3- into intestine
How is cholecystokinin (CCK) activated and what does it do?
Activated by fat and protein in duodenum, stimulates release of pancreatic enzymes and bile into intestine
Name two pancreatic hormone involved in digestion and absorption
Secretin and cholecystokinin (CCK)
Which substance inhibits pancreatic secretions? (secretin and CCK)
Somatostatin (inhibits secretin, CCK, and also gastrin in stomach!)
Which substance potentiates the actions of secretin and CCK?
ACh (acetylcholine) potentiates release of bicarbonate and pancreatic enzymes
(Because parasympathetic influence means rest and DIGEST!)
What happens in acute pancreatitis?
Pancreas begins to auto-digest due to blockage of pancreatic duct by bile duct stones
What is chronic pancreatitis often caused by?
Alcohol abuse
Give two significant symptoms of pancreatitis
. Steatorrhea (fatty stools because of poor fat absorption due to lack of pancreatic lipase)
. Diabetes (lack of insulin because pancreas damaged)
Why does pancreatitis not have a significant effect on carbohydrate and protein digestion?
Additional proteases/peptidases and amylase released in small intestine, so carbs and proteins can still be digested here
