This is the process where local concentric contractions spaced over a segement of the intestine to mix food.
Segmentation
What would happen to segementation if you gave an antimuscarinic drug like atropine?
it would be weak
This is the most basic form of propulsive movement.
Peristalsis
True or False: peristalsis in the SI is usually strong to get a food bolus from your stomach all the way to your colon.
False! It’s normally very weak.
Which reflex tells the SI to increase peristalsis when food enters the stomach?
Gastroenteric reflex
Which reflex tells the ileocecal valve to relax to allow chyme to pass from the ileum into the colon?
Gastroileal reflex
True or False: gastrin, CCK, insulin, motilin and serotonin increase peristalsis in the SI.
TRUE
True or False: secretin and glucagon increase peristalsis in the SI.
False, they decrease peristalsis activity.
Define: this is the powerful and rapid peristalsis of the SI due to intense irritation of the mucoa.
Peristaltic rush
When the cecum is distended, is the ileocecal sphincter relaxed or contracted?
contracted so poop doesn’t flow back into your ileum.
Which nervous system (ENS, PANS, or SANS) drives the regulation of the ileocecal sphincter?
enteric NS
Which cells release secretin?
S cells from the duodenum and jejunum
What is the the stimuli for secretin release?
Acid
Which 2 organs are stimulated to release HCO3 when secretin stimulates them?
Liver and pancreas
Which cells release CCK?
I cells from the duodenum and jejunum
Which substances trigger CCK release?
Fats and proteins
CCK triggers contraction of what organ?
Gallbladder
CCK inhibits which sphincter?
Sphincter of Oddi
CCK also triggers the release of enzymes from which organ for digestion?
Pancreas
These are the cells in the first part of the duodenum that secrete an alkaline mucous in response to irritating stimuli.
Brunners glands
These are the small pits located over the SI, that secrete mucus and water and electrolytes.
Crypts (of Lieberkuhn)
What are the products of pancreatic amylase on the digestion of carbs?
maltose + small polymers
What are the 4 carbohydrate enzymes that line the villi?
lactase, sucrase, maltase and a-dextrinase
What are the 2 sugars that are the products of lactase?
glucose + galactose
What are the 2 sugars that are the products of sucrase?
fructose + glucose
What are the 2 sugars that are the products of maltase?
glucose + glucose
These are the folds in the intestinal mucosa which increase the absorptive mucosa 3-fold
Valvulae conniventes
These are millions of 1mm projections from the mucosal surface to increase the absorptive area 10-fold.
Villi
This is the 1000 microvilli on each intestinal epithelial cell on each villus.
brush border
If you had to give me 1 word that described the absorption of water from chyme into the blood, what would it be?
Diffusion
True or false: water can leave the chyme and go to the blood by osmosic pressure, and it can leave the blood and go to the chyme from osmotic pressure as well.
True!
Once Na diffuses into the cell, how is it transported across the basal and side walls of the epithelia?
By active transport
When Na is absorbed into the intestinal epithelia, what other ion is “dragged” along with it?
Cl-
HCO3 in the chyme combines with what ion that is pumped into the lumen by the epithelial cells?
H+ (to form H2CO3)
H2CO3 splits in the lumen to form what 2 substances?
H2O and CO2
Which hormone activates vitamin D to cause absorption of Ca++ from the chyme?
PTH
Generally, this is the decreased absorption of the mucosa in the SI.
Sprue
This type of sprue is when gluten causes toxic effects on the intestinal enterocytes.
nontropical sprue.
This type of sprue forms from inflammation as a result of bacterial infection.
Tropical sprue
What is the first substance to be impaired in absorption in any sprue?
Fat
What is the term called when there are excess fats in yer poo poo?
Steatorrhea