Salivation Flashcards
What produces saliva?
Salivary glands
- sublingual glands
- submandibular glands
- parotid glands
What is saliva made up of?
Serous secretion
Mucus secretion
What produces the serous secretion in saliva?
Parotid gland
Submandibular glands
Sublingual glands
What produces the mucus secretion in saliva?
Submandibular glands
Sublingual glands
What is the serous secretion of saliva made up of?
Water
Amylase
Lingual lipase
Immune proteins
Kallikrien
What is the mucus secretion of saliva made up of?
Mucins
What is the function of amylase in saliva?
Digests starch
What is the function of lingual lipase in saliva?
Digests fats
What are the different immune proteins in saliva?
IgA
Lysozyme
What are the functions of immune proteins in saliva?
Destroy bacteria in the oral cavity
to protect against infection, ulceration, dental caries
What is the function of kallikrien in saliva?
Increases the production of bradykinin in blood vessels supplying the salivary glands
What is the effect of bradykinin in blood vessels?
Vasodilation
increased blood flow
What is the tonicity of saliva?
Hypotonic
What are the functions of mucins in saliva?
Lubrication
What is the ionic composition of saliva?
Low concentration of sodium and chloride ions compared to plasma
High concentration of potassium and bicarbonate ions compared to plasma
What is the pH of saliva?
7.5
slightly alkaline
Why is the pH of saliva slightly alkaline?
Because it has a high concentration of bicarbonate ions
What is the basic unit of a salivary gland?
Acinus, lined by acinar cells
Duct, lined by ductal cells
What do the acinar cells of salivary glands do?
Produce saliva
that is isoosmotic to plasma
Where does saliva from the acinar glands travel?
Travels through the ducts
along the ductal cells
What do the ductal cells of salivary glands do?
Change the ionic composition of saliva
to make it hypo-osmotic to plasma
How do ductal cells make saliva hypo-osmotic to plasma?
Na+ K+ ATPase on basolateral domain
actively transports 3 sodium ions out of the cell
2 potassium ions into the cell
NHE on apical domain
sodium ion diffuses into the cell from saliva down its concentration gradient
hydrogen ion is secreted from the cell into saliva
AE on apical domain
chloride ion diffuses into the cell from saliva down its electrical gradient
bicarbonate ion is secreted from the cell into saliva
H+ K+ ATPase on basolateral domain
potassium ion is moved out of the cell into saliva
hydrogen ion is moved into the cell from saliva
More sodium and chloride ions leave the saliva than potassium and bicarbonate ions entering the saliva
so it becomes hypo-osmotic
How does the tonicity of saliva change with change of flow of saliva through the ducts? Why?
As flow increases, saliva becomes more iso-osmotic to plasma
because less contact time with ductal cells
less transport of ions between saliva and ductal cells
What is the control of salivation?
Neural control
autonomic nervous system
What overall effect does the parasympathetic nervous system have on salivation?
Stimulates salivation a lot
How does the parasympathetic nervous system stimulate salivation?
Partly by vasodilating blood vessels supplying salivary glands
increased blood flow to salivary glands
increased delivery of nutrients to salivary glands
What is xerostermia?
Dry mouth
What are the causes of xerostermia?
Dehydration
What are the signs and symptoms of xerostermia?
Dysphagia
Ulcers
Oral candidiasis
Dental caries
What is a common cause of inflammation of the parotid gland?
Viral infection - mumps
What are the symptoms of inflammation of the parotid gland? Why?
Severe pain
because the parotid gland is enclosed in a fibrous caspsule, which limits swelling
What overall effect does the sympathetic nervous system have on salivation?
Stimulates salivation
but not as much as parasympathetic nervous system does
