Describe the components and digestive functions of saliva.
What are the functions of saliva?
- cleanses mouth - dissolves food chemicals for taste - moistens food... compacts into bolus - Begins breakdown of starch with enzymes
How much saliva per day?
1500 ml/day * Intrinsic glands keep mouth moist
Describe the composition of saliva...
97 - 99.5 % water, slightly acidic - Electrolytes (Na+, K+, Cl-, PO42-, HCO3-) - Salivary amylase & lingual lipase - Mucin - Metabolic wastes (urea & uric acid) - Lysozyme, IgA, defensins, & a cyanide compound protect against microorganisms
What are the major salivary glands activated by?
Parasympathetic Nervous System * happen when ingested food stimulates chemoreceptors in mouth.... SO THEN, Salivatory Nuclei in brain stem send impulses along parasympathetic fibers in cranial nerves VII and IX
What are the major salivary glands?
Parotid, Submandibular, Sublingual
What do the major salivary glands do?
Produce Saliva - Lie outside oral cavity
Where are the minor salivary glands?
Scattered throughout oral cavity, augment slightly
What are the 2 types of secretory cells in salivary glands?
Serous Cells - watery, enzymes, ions, bit of mucin Mucous Cells - mucus *Parotid & Submandibular glands are mostly serous *Sublingual mostly mucous
What inhibits salivation and results in dry mouth (xerostomia)?
sympathetic stimulation