Digestive System Flashcards
Where does peristalsis during digestion happen?
Stomach and esophagus
What happens before peristalsis in the stomach?
Segmentation (kneeding) to mix up material in stomach
How much can the stomach hold?
~3L food/liquid
Where is HCl made?
gastric pits of stomach
What’s the pH of the small intestine?
8-8.2
What is a major glycoprotein made in the stomach?
Intrinsic factor
What does intrinsic factor do?
Binds vitamin B-12, goes into small intestine and intestinal capillaries. Necessary for production of mature RBCs and normal neurological function
How did we get around our need for catalysts?
Developed enzymes to make/break bonds to create new products
What’s the average enzyme turnover rate?
1 million/sec
What role does fiber have in aiding digestion?
It traps water and stretches the small intestine which activates peristalsis
What do lacteals do in the small intestine?
Absorb the breakdown products of fats (they can’t go into intestinal capillaries because they’re not water soluble)
Name the portions of the small intestine from proximal to distal
Duodenum, jejunum, ileum
How much total water do the small intestines use for digestion and nutrient absorption daily? How much of it is used up?
9L/2L (7L goes into large intestine where it’s absorbed into the bloodstream and then returned to the tissues)
What happens when the large intestine is sensitive and water doesn’t get absorbed back into the bloodstreama?
Diarrhea.
Describe nutrient absorption in the small intestines
The breakdown of starch, glycogen, and proteins digested needs enzymes and water before it can move into the intestinal capillaries
List 8 functions of the liver
- facilitates digestion of lipids by producing bile 2. Stores fat-soluble vitamins, iron, and vit D hormone 3. Stores glycogen & thus helps regulate blood sugar levels 4. Stores lipids from unused glycogen 5. Uses amino acids from intestines to synthesize clotting factors and albumin 6. Inactivates toxins 7. Converts ammonia to urea 8. Breaks down old RBCs and secretes bilirubin into bile
How long is the small intestine?
28-32 ft
What area of the stomach has sensors for fullness that releases serotonin?
Fundus
How long does it take for the stomach to empty normally?
2-4 hours after meal
What is the time frame for “full” digestion?
24-72 hours start to finish
What is peritonitis?
Having bacteria in the abdominal cavity- can be fatal
What is and isn’t in bile?
NO ENZYMES. but bile has cholesterol, bile salts, ions, and pigments
What does lecithin do?
It acts as an emulsifier (acts as a “soap”). We can’t have oil going into large intestine undigested. Need emulsification mixing oil-based with water-based
What would someone with liver disease present with?
Probably BLEEDING- because they aren’t making clotting factors
What is albumin/where is it made? What does it do?
It is a binding/transport protein produced in the liver. 60% of all protein in bloodstream is albumin
How much gastric juice is secreted by the stomach each day?
2.5L
What does pepsin do?
Cleaves proteins into peptides
Name sections of the large intestine from proximal to distal
Cecum, ascending colon, transverse colon, descending colon, sigmoid colon, anal canal
