salivary secretion

what is the average daily volume of saliva produced?

1.5 liters every 24 hours

which salivary gland is the largest and what type of secretion does it produce?

the parotid gland; it is esclusively serous and produces "dilution saliva"

through which canal does the paratid gland discharge its secretion?

steno`s canal (opening near the upper second molar)

what is the serous-to-mucus ratio for the submadibular glands?

it is a mixed gland with a 4:1 ratio (predominantly serous)

which glands are predominantly mucous and aid in swallowing?

the sublingual glands (seroud-to-mucus ratio is 4:1)

what is the morphofunctional unit of a salivary glands?

the lobule

what is the normal pH and density of saliva?

pH is 6.0-7.0; density is 1.003-1.008

which enzyme breaks down cooked starch into dextrin?

salivary A-amulase (ptyalin)

what is the role of lisozyme in saliva?

it is a bactericidal enzyme that destroys microbial capsules

which substance is the main buffer system in saliva?

biocarbonate (HCO3-), responsible for 85% of buffering

how does potassium (K+) concentration in saliva compare to plasma?

it is 4x higher in saliva than in plasma

what can happen if saliva becomes too alkaline?

calcium may precipitate to form sailoliths (salivary stones)

where is the “primary secretion" formed, and what is its tonicity?

formed in the acini; is it isotonic

why is final saliva typically hypotonic?

because as its flows through the ducts, sodium (Na+) and chlorine (Cl-) are reabsorbtion, while k= and HCO3- are secreted

which branch of nervous system stimulates the production of abudant, watery saliva?

the parasympathetic nervous system

what is the effect of the sympathetic nervous system on saliva?

it leads to less abudant, more viscous saliva rich in mucus and proteins

what is the difference between unconditioned and conditioned reflexes?

inconditioned are triggered by food/mechanorecepters; conditioned are triggered by sight, smell, or thought of food

how do aldestorone and adh affect saliva?

aldosterone increases sodium reabsorption; adh reduces salivary volume to consere water