digestive and excretory systems Flashcards
(117 cards)
digestion
break down of food into smaller organic molecules for absorption
absorption
how nutrients really enter the body
bolus
broken down food with saliva
salivary amylase
begin breaking up sugars
esophagus
takes food from mouth to stomach where it enters a spincter
GERD
issue with the gastroesophageal sphincter where acid moves back up
pepsin
stomach protease
cleaved form of pepsinogen
- cleaves proteins at aromatic residue
parietal cells
cells of stomach that secrete stomach acid (acidic)
chief cells
secrete zymogen of pepsin known as pepsinogen, so no self destruction in stomach occurs
Foveolar cells
secrete bicarbonate to protect stoamch from acidiity
intrinsic factor
secreted by stomach to help absorb vitamin b12
pyloric sphincter
connects stomach and small intestine
portions of small intestine
dueodenum, jejunum, ileum
chyme after stomach
highly acidic and must be neutralized by small intestine
what structures contain brush border enzymes
microvilli in small intestine
types of brush border enzymes
disaccharidases, peptidases
pancreas
secretes digestive fluiid with enzymes for breakdown
liver
secretes bile , which breaks down all major macromolecules
bile
emulsify fats and help convert them into micelles
- produced in liver
gallbladder
where bile is stored and released from
how is the duedoenum alkaline when the stomach is acidic
pancreatic juices are alkaline, duedenum secretes bicarbonate , bile is alkaline
villi
fingerlike projections of small intestine that extend into lumen of the intestine and increase surface area
- lined with enterocytes
enterocytes
cells of intestinal lining with microvilli (increase surface area for cell funciton)
large intestine
ascending colon, transverse colon, descending colon, sigmoid coloon, rectum