Pancreas And Beyond- Fitz Flashcards
How much substance is absorbed by the SI?
6700 mL
How much water and solids are ingested vs excreted per day?
1200 mL of water -> 100 mL of water
500-800 g of solids -> 50 g of solids
How much substance is absorbed by the LI?
1400 mL
What two things tell pancreas there’s food in the stomach?
Vagus nerve
Pacinian corpuscle receptors
How does CCK finish what the vagus started in the pancreas?
Stimulates acinar cells for secreting enzymes
How does pH increase in the pancreas?
Pancreatic bicarbonate secreted first via secretin stimulation
Why would gastrin inhibit the pancreas?
Too much fat or protein still present in food
What does the exocrine portion of the pancreas do?
Produces pancreatic juice that is rich in bicarbonate and digesting enzymes
Which ducts come together at the sphincter of Oddi?
Pancreatic duct
Common bile duct
What is the substrate for [trypsin, chymotrypsin, elastase]?
Proteins
What does [trypsin, chymotrypsin, elastase] do?
Break peptide bonds in proteins to form peptide fragments
What is the substrate for carboxypeptidase?
Proteins
What does carboxypeptidase do?
Splits off terminal AA from carboxyl end of protein
What is the substrate for lipase?
Fats
What does lipase do?
Splits off two FAs from triglycerides, forming free FAs and monoglycerides
What is the substrate for amylase?
Polysaccharides
What does amylase do?
Splits polysaccharides into glucose and maltose
What is the substrate for [ribonuclease, deoxyribonuclease]?
Nucleic acids
What does [ribonuclease, deoxyribonuclease] do?
Split Nucleic acids into free mononucleotides
What is the endocrine portion of the pancreas?
Islets of Langerhan
What are the primary hormones made by the islets of Langerhan?
Insulin and glucagon
What do alpha islet tumor cells result in?
Diabetes
-glucagon
What do beta islet tumor cells result in?
Hypoglycemia
-insulin
What do delta islet tumor cells result in?
Diabetes
- somatostatin
- inhibits insulin and glucagon
Islet configuration connections:
:tj, desmosomes, gj
How many islets of Langerhan do we have?
1-2 million
What does glucagon resemble?
Secretin 29 AAs
GIP
VIP
What does glucagon do?
Cleave glycogen
Makes new glucose
What are the target organs for glucagon?
Liver
Adipose cells
What stimulates alpha cells -> glucagon?
AAs Ach EP NRE VIP CCK-PZ
What is insulin synthesized as?
A promolecule-> proinsulin
What does insulin look like?
Alpha chain with 21 AAs, Beta chain with 30 AAs
Linked by disulfide bonds
What was the first molecule made by recombinant DNA?
Insulin
What are insulin receptors like?
2 alpha chains bind to insulin
2 beta chains have tyrosine kinase domains
-phosphorylation and internalization
What inhibits beta cells -> insulin?
Somatostatin from delta cells
EP from sympathetic system
NRE from sympathetic system
What does pancreatic somatostatin do?
Regulates movement of nutrients
Regulates GH
Decrease acid secretion, motility
Slow absorption
What increases pancreatic somatostatin?
NRE - stimulates sympathetics
What decreases pancreatic somatostatin?
Ach - inhibits parasympathetics
What does pancreatic polypeptide do?
Suppresses pancreatic somatostatin
Inhibits gall bladder and pancreas secretion
Reasons for gall bladder removal:
:gall stones, cancer, dysfunctional (not enough bile ejected)
What side of the body is the liver on?
Right
What does the liver do?
Produce bile