Saliva Flashcards
briefly explain the journey of saliva secretion
starts in the acini (primary secretion)
this secretion travels along the intercalated ducts
these intercalated ducts feed into the straited ducts
the saliva goes onto the secretory ducts
enters the oral cavity
where is the initial salivary secretion made?
acini
which salivary ducts modify the saliva?
striated ducts
why do the striated ducts modify saliva?
they have folded basal membranes
as you get closer to the mouth, the walls of the cells become more stratified, due to multiple layers of the cells lining the wall, true or false?
true
what shape is the central lumen?
ball shaped
what are the 3 types of secretion you can get?
serous
mucous
serous demulines (serous cells around mucus acinar)
what are the physical features of serous acinus?
clearly seen nucleus
nucleus is quite large
what are the physical features of mucous acinus?
has a basal nucleus squashed down to the basal aspect of the cell
are serous acinar cells purple/pink or pale down a microscope?
purple/pink
why do serous acinar cells stain purple?
due to their basophilic rough endoplasmic reticulum
are mucous acinar cells purple/pink or pale down a microscope?
pale
what is attached to the surroundings of acini and intercalated ducts?
myoepithelial cells
what is the function of myoepithelial cells?
can help push the saliva down the ducts faster
what is the physical features of intercalated ducts?
cuboid shape
large central nucleus
intercalated ducts are passive, true or false?
true
do intercalated ducts modify saliva?
no
How striated ducts change the composition of saliva depends on what?
the rate of flow through the salivary gland
if saliva flows through these ducts quickly, will there be more or less change?
more
why do striated ducts have a central nucleus?
massive basal membrane folding
within the basal folds, what are present which explain why the cell is very active with membrane pumps and exchanges?
mitochondria
what are secretory ducts also referred to?
collecting ducts
what ducts empty into the secretory ducts?
striated ducts
which ducts are the largest in diameter?
secretory
what does the secretory ducts eventually merge with?
stratified squamous oral epithelium
what are the main constituents of saliva?
water
electrolytes
organic components
what are the main electrolytes making up saliva?
sodium potassium chloride
bicarbonate
when an acinar cell is in its resting period is the concentration of sodium outside the cell low or high?
high
when an acinar cell is in its resting period is the concentration of potassium outside the cell low or high?
low
when an acinar cell is in its resting period is the concentration of sodium inside the cell low or high?
low
when an acinar cell is in its resting period is the concentration of potassium inside the cell low or high?
high
when a nerve comes along and activate the cell this causes what?
an increase in the membrane permeability to potassium
potassium leaks out the acinar cell because there is too much of it, where does it go?
into the lumen and the connective tissue
what does the co transporter consist of?
sodium
potassium
chlorine
what triggers the co transporter?
the increase in extracellular potassium
what is the purpose of basal sodium and potassium pumps?
pumps sodium out the cell and potassium in at the same time
to maintain the contents of the lumen and ensure they are the same in the connective tissue
the sodium that is pumped in by the co transporter is removed by what?
basal sodium and potassium pumps
an opening of chloride channels allows what?
the increase. of chloride ion to flow out
what attracts sodium into the acinar cell and why?
chloride- drawn into secretion to balance charge
why is water dragged down the osmotic gradient between the acinar cells?
to address the osmotic imbalance
what does isotonic mean?
same concentration as tissue fluid
what does hypotonic mean?
less concentrated solution
in ductal modification, is there a conversion from isotonic to a hypotonic solution or from hypotonic to an isotonic solution?
isotonic to hypotonic
what is an key salivary component that neutralises acid?
bicarbonates
in what duct does bicarbonate secretion take place?
striated duct
in what duct does ductal modification take place?
striated duct
what is in in the single striated duct cells that modify salivary constituents?
they have a folded membrane, its these folds that do the modification
at rest is the striated duct cell permeable or impermeable to water?
impermeable
Inside the cells we have low potassium, low sodium and low chloride, true of false?
false
we have high potassium, low sodium and low chloride
outside the cell we have high sodium, high potassium and high chloride, true or false?
false
we have high sodium, low potassium and high chloride
is there more sodium potassium pumps in the acinar cells or the striated cells
striated because these cells work harder to modify saliva
what are the compensatory movements from the lumen in the striated duct cells?
As sodium is taken out the cell, sodium correspondingly is dragged out of the secretion
Similarly as potassium is added to the striated ducts through the permeability of the membrane, its pushed in
what is the result of an activated striated duct cell?
The result is as the saliva flows through the striated ducts we get an increase in potassium concentration and a decrease in sodium concentration and also a decrease in chloride as the chloride follows the sodium out
what is a chloride bicarbonate exchanger?
an active pump that exchanges chloride for bicarbonate, actively adding bicarbonate to the secretion and removes chloride
what is the known buffering component of saliva and why?
bicarbonate- it counteracts ph changes
what effects the concentration of saliva?
the speed it travels through the ducts
if the saliva flows through the ducts slowly what does this result in?
more time for sodium to be reabsorbed, resulting in low concentrations of saliva
if the saliva flows through the ducts fast what does this result in?
less time for reabsorption of sodium, less reduction of sodium, higher concentration in saliva
when is bicarbonate added into the saliva
in the striated ducts