3.5 Gastrointestinal Physiology Flashcards
mucus of SI comes from what glands?
Brunner’s glands
fluid of SI is released from?
Crypts of Lieberkuhn
*like interstitial fluid
digestive enzymes of SI released by? Describe these enzymes***
Crypts of Lieberkuhn
**digestive enzymes perform the FINAL BREAKDOWN of nutrients; are brush border enzymes
what are the 3 main things secreted by SI?
mucus
fluid
digestive enzymes
What are brush border enzymes? Give examples?
disaccharidases, intestinal lipases, peptidases, enterokinase
* connected to WALL
function of disaccharidases?
split disaccharidase into monosaccharidases
function of intestinal lipases? another name for them?
splits triglycerides into Di and Mono
*another name is enteric lipases
function of peptidases?
final splitting of small peptides
what is the primary and most important regulator of SI secretion?
distention! Simply having food in there
What are the two forms of SI secretion regulation?
1) distension
2) neural (cephalic or gastric) can also stimulate SI secretion —minor importance
What is the secretino of liver?
bile
what is the most important component of bile?
bile salt; most important and most abundant to GI function (bilirubin can give important info regarding liver heath)
what is bile mostly composed of?
water
what is the components of bile?
water, electrolytes, cholesterol, lecithin, bile salts and bilirubin
bile salt synthesis?
cholesterol > cholic (chenodeoxycholic) acid + glycine or taurine > glycocholic or taurocholic conjugated bile acid
glycine or taurine used more in making of bile salts?
glycine
purpose of bilirubin?
liver incorporates bilirubin into bile after destruction of RBCs to get rid of it and gives bile its color. But since it is in the bile, it gives an indicator of liver heath (like how well it is breaking down RBCs and dealing with waste like bilirubin)
why do we need bile salts?
- transport
* fat breakdown (emulsification)