Salivary Glands Flashcards
Functions of the salivary glands?
Oral hygiene - immunity - antibacterial
Oral pH needs to be maintained at about pH 7.2
- bicarbonate buffer system
Contains digestive enzymes
Flow rate of saliva?
What makes it vary?
How much a day?
0.3 ml to 7ml
Silent, sleeping — talking and eating
About 1.2l of secretions a day
Flow rate also affected by drugs and age
How is defence provided by the oral cavity etc?
Mucosa - physical barrier
Palatine tonsils - lymphocyte subset and also contains dendritic ells
Salivary glands - washes away food particles, bacteria and viruses
The salivary glands are also surrounded by lymphatic system linked to thoracic duct and blood
Structure of salivary glands:
Composed of acinar cells around a duct that will enter the mouth
The acinar cells produce saliva
Have serous and mucous acinus
Serous = water and amylase
Mucous = water and glycoproteins
Striated ducts:
Appearance
Function
= striated, basal membrane highly folded into microvilli for AT of HCO3.
Microvilli filled with mitochondria for energy to facilitate AT
Found in salivary glands
How saliva changes from acinar cells down the ducts?
Primary saliva - NaCl rich isotonic plasma secreted by acini
Ducts secrete K+ and HCO3- and reabsorb NA+ and Cl-
Parotid glands
Anatomy
Function
Found in front of the ear between the zygomatic arch and mandible
Structures that pass through = external carotid artery, facial nerve
The parotid capsule very tough
Main source of saliva when stimulated
Parotid is a serous gland
Submandibular glands
Anatomy and function
The submandibular gland is located within the anterior part of the submandibular triangle. The boundaries of this triangle are:
Superiorly: Inferior body of the mandible.
Anteriorly: Anterior belly of the digastric muscle.
Posteriorly: Posterior belly of the digastric muscle.
Secretions from the submandibular glands travel into the oral cavity via the submandibular duct (Wharton’s duct). This is approximately 5cm in length and emerges anteromedially from the deep arm of the gland between the mylohyoid, hypoglossus and genioglossus muscles. The duct ascends on its course to open as 1-3 orifices on a small sublingual papilla
The submandibular glands are bilateral salivary glands located in the face. Their mixed serous and mucous salivary secretions are important for the lubrication of food during mastication to enable effective swallowing and aid digestion.
See histology of the glands on histology
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Sublingual glands anatomy and function:
The sublingual glands are almond-shaped and lie on the floor of the oral cavity. They are situated underneath the tongue, bordered laterally by the mandible and medially by genioglossus muscle of the tongue,
The glands open by the lingual frenum - ligament under the tongue
Secretions drain into the oral cavity by minor sublingual ducts.
Minor glands - continuously active - produces both mucous and serous
What are the 4 types of salivary glands?
Parotid - serous (enzymes and water), main source of saliva when stimulated
Submandibular - mucous and serous (whole time)
Sublingual - mucous and serous (whole time)
Minor salivary glands - mainly mucous - found in the labial, palatial and lingual regions
Parasympathetic and sympathetic nervous system affect on the production of saliva?
Para = increases production of saliva
with the glossopharyngeal nerve innervating the parotid, and the facial nerve innervating the submandibular and the sublingual glands.
Sympathetic = decrease production of saliva
Xerostomia, what is it? Why?
= dry mouth
When salivary function falls below 50%
Low natural hygiene
Poor pH control
Infections
Plaque etc
May be a consequence of cystic fibrosis
Most commonly a consequence of medication
What is an obstructive salivary gland disease?
Saliva contains calcium and phosphate ions - can form stones
Most often in submandibular gland, block at bend
What can happen after your salivary gland becomes blocked?
It can become inflamed (inflammatory salivary gland disease)
Mumps is an example
Swelling of of glands - pains over parotid as parotid gland can not expand - tough capsule
