Digestive System

  1. describe the composition of stomach mucosa
    mucous cells produce alkaline mucus where gastric glands within gastric pits secrete gastric juices containing intrinsic factor - which is needed to absorb vitamin B12
  2. describe the composition of gastric pits
    • gastric pits produce pepsinogens - protein digesting enzymes
    • parietal cells = produce HCL
    • entereoendocrine cells - produce gastrin hormone
  3. describe the composition of the small intestine
    • consists of a muscular tube from the pyoloric sphicter to the ileocecal valve which is suspended from the posterior abdominal wall by the mesentary
    • it is the site of nutrient absorption into blood
  4. describe the subdivisions of the stomach
    • duodenum
    • jejunum
    • illeum
    • where the large intestine meets the ileocecal valve
  5. chemical digestion in small intestine
    • includes enzyme produced by intestinal cells, pancreas
    • pancreatic ducts carry enzymes to duodenum which contains bile
    • made in liver and stored in gall bladder where it enters in the duodenum
  6. describe the absoprtion in small intestine
    • greater surface area for absorption of nutrients due to¬†
    • microvilli - tiny projections of plasma membrane.
    • villi - fingerlike projections of mucosa with capillaries
    • circular folds - folds o mucosa and submucosa
  7. describe the physiology of large intestine
    • larger in diameter, shorter length than small intestine
    • illeocecal valve to anus
    • expels indigestable food reside from the body (producing feces)
  8. colon
    • ascending colon includes digested food where it travels up R side of abdominal cavity.
    • transverse colon - travels across
    • descending colon - down L side
    • sigmoid colon - S-shaped, enters pelvis
  9. anus
    • external anal sphincter = skeletal muscle, voluntary control
    • internal anal sphincter - smooth muscle, involuntary
    • sphincters normally closed except during defecation
  10. Accessory Digestive Organs
    • includes teeth
    • salivary glands
    • pancreas
    • liver
    • gallbladder
  11. Teeth
    • 32 permanent teeth
    • classified anteriorly to posterior¬†
    • incisors
    • canines
    • premolars
    • molars
Card Set
Digestive System
cram before the test