25 - composition of saliva. Stimulated and unstimulated salivary flow. Fcators influencing salivary flow and composition

composition of saliva

• 600-1000ml a day, 99.5% is made up of water

• Electrolytes - Eg. sodium, potassium, calcium, magnesium etc

• Secretory proteins - Eg. amylase, lipase, mucins, lysozyme

• Immunoglobulins - IgA, IgG, IgM

• small organic substnaces - glucose, amino acids, urea, uric acid and lipid molecules

• Other components - insulin, epidermal growth factor, CAMP binding proteins and albumin serum

• Antimicrobial compounds - Eg. hydrogen peroxide, lactoferrin

cellular composition of saliva

• basic secretory units - acini, serous acini, mucous acini

• epithelial cells

• neutrophils

• lymphocytes

• bacterial flors

types of salivary flow

• stimulated - response to stimulus

• Unstimulated - resting salivary flow (no stimulus)

stimulated salivary flow

• stimuli - chewing, medication, taste

• Stimulated - related to size of salivary gland

• Contribution of the glands during stimulated - over 50% of salivary secretion from parotid gland

• Typically 1.5ml-2.0ml per min

• Saliva passes through salivary duct rapidly

Unstimulated salivary flow

• unstimulated - not related to size of salivary gland

• Contribution of the glands during unstimulated - 20% by parotid glands, 65% by submandibular, 7% by sublingual and 10% by minor salivary gland

• Typically - 0.2ml-0.3ml per min

Factors influencing salivary flow and composition

1. Circadian rhythm

• Morning - highest production rate of Na and Cl

• End of afternoon - highest concentration of proteins and salivary flow

• Night (sleep) - lowest amount of salivary flow

2. Medications

• Reduce salivary flow

• Medications like - antidepressants, antihistamines and antipsychotics

3. Chewing gum

• Increases amount of stimulated salivary flow