Digestive System Flashcards
What’s bolus?
Saliva breaks down food into particles and convert it into a ball called bolus to go down the esophagus
What’s peristalsis?
Systematic contraction and relaxation of esophagus to send the bolus to stomuch
What happens when chyme leaves the stomach?
It enters into first part of small intestine, duodenum, through pyloric sphincter. The lining of duodenum gets stimulated and secretes a bunch of enzymes called brush border
What are brush border enzymes?
Peptidases breaks down peptides into amino acids
Disacchridases breaks down carbohydrates into disaccharides and glucose
What prevents acidic chyme from inactivating enzymes?
Peptide hormone, secretin, that stimulates pancreatic enzymes to release into duodenum and regulates pH by reducing HCl
What’s bile used for?
It’s composed of salts, pigments, and cholesterol and produced by liver and stored in gallbladder to breakdown the fat into micelles
What do micelles do?
Prevent fats from separating out and increases surface area for fats which allows water soluble enzyme (pancreatic lipase) to interact with fats and break them down
How are nutrients absorbed?
The other parts of small intestine, jejunum and ileum, have higher surface area and villi (fingerlike projections) allow for more nutrient absorptions
What does liver do to store energy?
It coverts glucose to glycogen and fats to triglycerides for later use
Where does undigested food enter from small intestine?
It enters into large intestine (cecum) through ileocecal valve and then to colon which absorbs any leftover water and salts and then turns the rest into stool to be excreted
What does rectum do?
It stores the stool and excretes it out of the body through anus by opening sphincters
