Chapter 11.8 - Digestive System Flashcards
Villi are located in the:
small intestine
Why are villi important?
increase surface area of small intestine to increase the efficiency of absorption
On top of each villus, there are tiny projections known as:
microvilli
Function of microvilli
further expand the surface area to help in nutrient absorption
____ are the absorptive cells that make up the villi
enterocytes
Enterocytes are lined with:
microvilli
Crypts
invaginations in the wall of the small intestine
Crypts contain what kind of cells?
those that secrete enzymes and that produce epithelial cells
Within the structure of a villus, there are:
lacteals (blood capillaries and lymphatic capilary)
What is absorbed into villus blood capillary?
glucose and amino acids
What is absorbed into villus lymphatic capillary?
fatty acid and glycerol
When is secretin released?
when chyme enters small intestine
Secretin stimulates:
the panceas to secrete HCO3- (bicarbonate) into duodenum via pancreatic duct
What hormones are released when chyme enters small intestine?
secretin, CCK
CCK function
- slows down gastric emptying
- signals pancreas to release digestive enzymes
- signals gallbladder to release bile
What does bile do?
emulsifies fat into small droplets (mechanical, not chemical digestion!!)
Pancreas secretes what enzymes?
- pancreatic amylase
- pancreatic lipase
- trypsinogen (activated by enteropeptidase to make trypsin)
- chymotrypsinogen (activated by trypsin to make chymotrypsin)
How does the liver perform blood maintenance?
- stores blood
- filters and detoxifies blood coming from the digestive system
- erythrocyte destruction via kupffer cells
- bacteria destruction via kupffer cells
- chemical/drug detox
How does the liver perform glucose metabolism?
via glycogenesis, glycogenolysis, gluconeogenesis
How does the liver perform protein metabolism?
- synthesizing plasma proteins (albumin)
- synthesizing non-essential amino acids
- converts dangerous ammonia to urea for safer excretion
Pathway of digested food in large intestine
cecum –> colon –> rectum –> anus