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