Glossary of Digestive System - Class Notes

Start Studying! Add Cards ↓

Three sections of small intestine
4 layers of intestine
Serosa (outside, thin layer)
Tunica muscularis (smooth muscle)
Mucosa (Houses specialized epithelial cells)
Monosacrides (carbohydrates) that can be absorbed by the gut.
What is leptin and what does it do?
Hormone secreted by fat cells.

More leptin:
Decrease food intake
Increase energy expenditure:
Increase temp.
Increase O2 consumption
What two sugars comprise Lactose?
Glucose and galactose
Propulsion through the digestive system is also called ____
Effect of distention in

Lower stomach

Upper stomach
Lower: Vigorous contraction

Upper: relaxation of resevoir
What activates pepsinogen? What does it become after activation?
Pepsin itself (autocatalytic)

What are the three activator receptors on a parietal cell?
acetycholine (Nervous system)
3 phases of gastric function
cephalic phase
gastric phase
intestinal phase
What hormone is secreted by the gut when acidic chyme is detected? What is the effect of this hormone on the stomach?
Slows down the digestion in the stomach.
What enzymes are secreted by the pancreas which digest protein?
chymotrypsinogen => chymotrypsin when activated

trypsinogin => trypsin when activated
What enzyme is secreted by the pancreas to convert starch to maltose?
What class of enzymes is released by the pancreas to digest protein. What are two members of this class?

What activates the pancreas to secret HCO3-?

To secret enyzmes?

What activates trypsinogen?
The brush boarder enzyme enterokinease
Give the steps for digesting lactose
Brush boarder enzyme lactaid breaks lactose into free glucose and galactose molecules. Na+ and then Glucose binds to Na+ dependent hextose transporter. Glucose transported into cell. Transporter flips back and galactose is transported into cell in the same manner.
Four Pregastric "processes"
Prehension - Food intake

Mastication - Chewing. Fracture into
smaller pieces so enzymes can attack.

Salivation - Lubrication, Solubilize
-> taste

What are two ways to reduce the production of stomach acid? They involve a___ of h____ and elimination of P___ P____.
Antagonists for Histamine.
Elimation of proton pump.
If the gut looses its lactaid brush boarder enzyme, what will be the result when lactose is ingested?
The lactose will result in a high os molarity in the gut and water will diffuse into the gut => diarrhea.
The folds in the gut consist of the v___ and the c___
villus, crypt
Method for removing Na+ from an epithelial cell of the gut
Na+/K+ ATPases (pumps) in the basolateral surface. Na+ is pumped into the region between two cells. It then moves to a nearby blood vessel.
Hepatocytes secrete B___ into the B____
Bile consists of
H2O, Na+Cl-, HCO3-,
cholesterol, bile salts,
bilribubin (bile pigment)
Show the two chief components of bile acids and indicate which part is hydrophobic, lipohillic, etc.
cholesterol amino acid
hydrphobic hydrophillic
lipohillic lipophobic
Two types of motion in the gut
peristalsis - propulsive
segmentation contractions - mixing
What enzyme digests triglcerides? What are the resultant molecules?

monoclyceride + 2 fatty acids
What hormone is secreted by the gut when fat and proteins are detected? What is the effect on the stomach? On the pancreas? On the gallbladder?
CCK (cholecystokinin)
Slows down the action in the stomach.
Stimulates pancreas to secrete enzymes into the gut.
Stimulates the gall bladder to contract and release bile to the gut.
___ from the ____ breaks a glob of trigylceride into small droplets. ___ from ____ digests these droplets into monoglyceride plus two free fatty acids.
Bile Salts, Liver
Lipase, pancreas
Give the steps for digesting and absorbing starch
1) Amylase from pancreas breaks starch into maltose.
2) Maltase (brush boader enzyme) breaks maltase into glucose and glucose
3) Na+ binds to Na+ dependent hexose transporter...opens glucose receptor
4) Glucose binds
5) molecule flips (Na+, G inside cell)
6) Na+ falls off
7) Glucose falls off
8) Molecule flips back to face lumen of gut.
Four main types of cells in the gastric pit of the stomach and what they secrete. Also give the order in which they are found in the pit - top to bottom.
Mucus cell - mucus
Parietal cell - HCL (and intrinsic factor)
Chief cell - Pepsinogen
G cell - Gastrin (stimulates parietal cell)
Where are mature absorptive cells found in the gut? How often do epithelial cells slough off and get replaced?

Where are stem cells found?
Top portion of the villa.

Every few days

Bottom of the crypt.
Effect of distention of gut - due to entrance of chyme - on the stomach. What mechanism is used to deliver the message to the stomach?
Slow down signal sent to gut by the enteric nervous system when distention is sensed in the gut.

Add Cards

You must Login or Register to add cards