Salivation Flashcards
what is the other name for the parotid duct
stensons duct
where does the submandibular gland open into the oral cavity
lingual frenulum
what is the name for the submandibular duct
whartons duct
where is the sublingual gland
base of the tongue
where does the sublingual gland open into the oral cavity
floor of the oral cavity, through 10-20 ducts
describe the innervation of the submandibular and sublingual glands
facial nerve, found in the superior salivatory nucleus
via the chordae tympani in the middle ear cavity
parasympathetic innervation
describe the components of the chordae tympani
facial nerve
taste fibres
salivatory fibres
describe the innervation of the parotid gland
glossopharyngeal nerve in the inferior salivatory nucleus, goes through jugular foramen through middle ear cavity then through the foramen ovale to provide parasympathetic fibres
describe the sympathetic innervation of the salivary glands
T1-T4 spinal nerves form the superior cervical ganglion, fibres course around the head and neck like the carotid artery
go to different salivary glands
what is the goal of parasympathetic innervation for salivation
watery saliva with lots of electrolytes
what is the goal of sympathetic innervation for salivation
protein rich, viscous saliva
basic structure of salivary glands
acinus surrounded by acinar cells, move into ducts surrounded by ductal cells
what produces acetylcholine
parasympathetic nervous system
what produces noradrenaline
sympathetic nervous system
what are the primary ions in saliva
sodium ions
potassium ions
chloride ions
bicarbonate
calcium
phosphate
water
how does water enter the acinus
- aquaporin 5 allows water to go from acinar cell to acinus
- water can move between the cells via paracellular transport
- can enter acinar cell via aquaporin 3 and then go to acinus via aquaporin 5
how does sodium enter the acinus
- paracellular transport
- NaKCl2 pump
how does potassium enter the acinus
- NaK pump on basolateral membrane
- NaKCL2 pump
this gets K into the acinar cells
from there, apical membrane takes potassium ions out of the acinus in exchange for a proton
how does chloride enter the acinus
NaKCL2 cotransporters pump in two chloride ions
CFTR allow chloride ions to leak into the acinus
how does bicarbonate enter the acinus
cells produce carbon dioxide, which combines with water in the cells in the presence of carbonic anhydrase to form carbonic acid, which breaks down into protons and bicarbonate
bicarbonate is then excreted into the acinus
some chloride ions go into the cell and maintain electrical activity
describe the tonicity of primary secretions
sodium and chloride being pulled into the acinus is the same as the volume of water, so the primary secretion is isotonic
what are the final ion amounts after ductal modification
- low sodium and chloride
- high potassium, water, bicarbonate
what is the tonicity of modified saliva
hypotonic
what does hypotonic mean
the concentration of solute is less than the water
how is sodium levels decreased in ductal modification
sodium molecules are taken into the ductal cells from the primary secretion
proton is pumped out in exchange
how are chloride levels decreased in ductal modification
chloride pulled into ductal cells in exchange for bicarbonate
describe the action of acetylcholine on the acinar cells
binds to M3 muscarinic receptors
leads to increased secretion of water, sodium, chlorine, potassium etc to increase the volume of watery, electrolyte rich saliva
describe the action of noradrenaline on the acinar cells
binds to beta 2 adrenergic receptors to release granules with protein and enzymes - mucin and amylase
increased secretion of viscous saliva
constricts the vessels to decrease flow and decrease electrolyte and water secretion
what are some protective molecules in the saliva
IgA
cystatins
histatins
lysozyme
proline rich proteins
function of histatins
kill bacteria and fungi
function of lysozyme
break down bacterial cell walls and digest food
function of proline rich proteins
remineralise the teeth
functions of saliva
- oral hygiene
- antimicrobial
- chemical digestion
- hydrate oral cavity and food
- increase the taste of food
- decrease caries
how does saliva increase taste of food
lubrication of food allows for better absorption into the taste buds