Physiology Flashcards
Which cells in the pancreas secrete digestive enzymes?
Acinar cells
Which cells in the pancrease secrete large volumes of sodium bicarbonate?
ductules
Trypsin, chymotrypsin, and carboxypeptidase all break down what substance in the gut?
Proteins
Pancreatic amylase breaks down what substance in the gut?
Carbohydrates
Lipase, esterase, and phospholipase all break down what substance in the gut?
Fats
What is the product of pancreatic lipase on neutral fats?
FA + 2-MG
What is the product of phospholipase on phospholipids?
FA’s
This enzyme converts the zymogen trypsinogen to the active form, trypsin.
Enterokinase
This molecule from the cytoplasm of glandular cells prevents the activation of pancreatic enzymes within the pancreas.
Trypsin inhibitor
What happens to the trypsin inhibitor to cause pancreatic damage in acute pancreatitis?
It’s overwhelmed by pancreatic enzymes because the pancreatic duct is blocked.
In order to form HCO3 to eb secreted from the pancreatic ductule cells, which gas must first enter the cell from the blood?
CO2
CO2 combines with what substance to eventully form H+ and HCO3-?
H2O
Where does the H+ go from the ductule cell once it’s synthesized?
back into the blood through an Na/H active antiporter
How does HCO3 get into the lumen once Na diffuses into the ductule lumen?
Active transport (mainly by a Cl/HCO3 exhanger)
The increase in this salt in the lumen causes the pull of what substance into the lumen as well?
H2O
The CFTR channel allows the diffusion of what ion from the pancreatic ductule cell into the lumen for HCO3 secretion?
Cl-
This condition is when the CFTR channel is missing/mutated so Cl- cannot be secreted, and the mucus becomes thick and clogs the lumen.
Cystic fibrosis
Ach works on these Gq receptors to increase pancreatic enzyme secretion.
M3
CCK and gastrin work on these receptors on acinar cells to increase pancreatic enzyme secretion.
B receptors
Secretin acts on these cells to increase bicarbonate secretion via a Gs pathway.
ductal cells
During the cephalic phase of digestion, Ach causes pancreatic enzyme secretion via what nerve?
X
This substance is secreted by the liver, stored in the gall bladder,a nd ejected into the SI.
Bile
After the hepatocytes make the bile acids, which tubes are they secreted into?
Bile canaliculi, which flows down to the terminal bile ductules.
The excess presence of what molecule can lead to the formation of gallstones in the gallbladder?
cholesterol
What kind of diet can lead to the formation of gallstones?
High fat
To much absorbtion of what substance can also form gallstones?
Water (cholesterol will precipitate)
The active transport of what ion out of the gallbladder wil concentrate the bile acids?
Na (cuz it drags other ions and water too)
What are the 4 main components of bile secretions?
Bile saslts, bilirubin, cholesterol, and lecithin
What % of bile salts are reabsorbed in the ileum?
95%
Will there be an increase or decrease secretion of bile from the liver with increased bile acids?
Increased
Will there be an increase or decrease secretion of bile from the liver with CCK?
Increase
Will there be an increase or decrease secretion of bile from the liver with secretin?
Increase (mainly HCO3 secretion)
These liver cells make bile, metabolize organic compounds, store stuff, and carry out all the functions of the liver.
Hepatocytes
These liver cells line the sinusoids and form a barrier between the portal venous system and the space of Disse (area where lymph flows).
Endothelial cells
These liver calls are macrophages and are part of the reticular endothelial system, which eat foreign debris and bacteria.
Kupffer cells
This condition is when a large clot blocks off the portal vein and causes an increase in liver capillary pressure of 15-20mmHg
Portal HTN
This condition occurs when liver parynchymal cells are destroyed and the resultant fiberous tissue obstructs the bile ducts.
Cirrhosis
What is the main cause of cirrhosis?
alcoholism
This is the condition when intersitial fluid is formed out of the liver itself and into the abdominal cavity as a result of hepatic HTN
ascites
beer belly lol
What is the life span for RBC’s?
120 days
So we’ve been over the entire lifecycle of the hemoglobin when it’s broken down. Now give me everything from the hemoglobin itself –> excretion from the body.
Hemoglobin –> blood –> eaten by macrophages –> heme + globin –> heme split to free iron (taken up by transferrin) + biliverdin –> free bilirubin –> liver –> conjugated with glucorinic acid –> conjugated bilirubin –> bile –> intestines –> converted by bacteria to urobilinogen –> conversion to urobilin for urine excretion or conversion to stercobilin if in feces.
This is the condition where there are large amounts of bilirubin in the extracellular fluids.
jaundice
This type of jaundice is when there is an increased destruction of RBCs and the subsequent release of lots of Hb and resultant bilirubin.
Hemolytic jaundice
This type of jaundice is when there is a blockage of the bile duct or liver cells so that bilirubin cannot be excreted out.
Obstructive jaundice
What are the 2 main contirbutors to obstructive jaundice?
Gallstones or cancer
True or False: there is excess urobilinogen in obstructive jaundice because of the blockage of the bile duct.
FALSE. there is NO urobilinogen because bilirubin cant get into the intestines to get converted.
What is the color of the stools in obstructive jaundice?
Clay-colored
What is the name of the test to see the levels of unconjugated or conjugated bilirubin in the blood?
Van Bergh test
High levels of conjugated bilirubin on the Van Bergh test show which type of jaundice? Hemolytic or obstructive?
Obstructive, as conjugated bilirubin cannot out.
