Phys 65: GI secretion Flashcards
Cells on surface of GI epithelium
Goblet cells AKA mucous cells
Invaginations of epithelium into submucosa aka
Pits
called crypts of lieberkün in intestine
Glandular cell secretions accomplished via
Exocytosis
Daily secretion of saliva amount
800-1500 ml
Average 1000ml
Two major saliva protein secretion types
Serous secretion
Mucous secretion
Salvia serous secretion protein
ptyalin
type of α-amylase
disgests starches
Mucous saliva secretion protein
Mucin
Acts as lubricant
Ions of saliva
Large quantities of HCO3- and K+
Na+/K+ balance in saliva
Na+ is reabsorbed in exchanger for K+
Cl- during saliva production
Reabsorbed passively
Factors in saliva that destroy bacteria
Thiocynate ions
Proteolytic enzymes —> most important is lysozyme
Antibodies
Superior salivatory nucleus CN
VII
Inferior salivatory nucleus CN
CN IX
Esophageal secretion type
Mainly mucous for swallowing lube
Oxyntic glands secrete
Hydrochloric acid, pepsinogen, intrinsic factor, mucus
Pyloric glands secrete
mainly mucus
also some gastrin
Eenterochromaffin like cells secrete
Histamine
Main driving force for hydrochloric acid secretion
H+/K+ ATPase
Basic factors that stimulate gastric secretion
Acetylcholine
Gastrin
Histamine
Intrinsic factor secreted by
Parietal cells