Oral and Gastric Physiology and Biochemistry Flashcards
How much saliva do you produce per day?
1 liter
Name the three major salivary glands and their innervation.
Parotid - Glossopharyngeal IX
Submaxillary - Facial VII
Sublingual - Facial VII
What is the function of lysozyme in saliva?
kills gram positive bacteria (but not gram negative)
Cleaves beta 1,4-linkages between NAM and NAG (in fungi too!)
What are some other components of saliva that act as bacterial defense?
Peroxidase: kills by producing reactive bromide and iodine molecules
Lactoferrin: binds iron and prevents bacteria/fungi growth
IgA: immunoglobulins that bind bacteria and induce immune reactions
Defensins: Antimicrobial polypeptides, form pore complexes on cell membranes
Mucins: modulate bacteria adhesion to oral tissues (teeth)
What are mucins?
lubricants in saliva
anti-microbial
found throughout GI tract
highly O-glycosylated
What are some ionic components of saliva?
high HCO3- neutralizes bacterial produced acids
low Na+ and Cl-
Name some viruses that saliva can carry.
Human herpes Herpes simplex EBV Mumps Rabies HIV
What are some conditions that can cause xerostomia?
Cystic fibrosis: mutant chloride transporters to plasma
Sjogren’s syndrome: autoantibodies to salivary gland proteins
Three phases of gastric secretion.
- cephalic
- gastric
- intestinal
ACh
Stimulates HCl & histamine secretion
Inhibits Somatostatin secretion
What stimulates the secretion of gastrin?
Gastrin related peptide
What stimulates secretion of somatostatin?
HCl
Gastrin
What does somatostatin inhibit?
Gastrin
Histamine
HCl
What does histamine do?
Stimulates parietal cell HCl
What digests fat?
lingual lipase (salivary glands) gastric lipase (chief cells)
