Salivary Glands Flashcards
Give the composition of saliva
99% water, 1% dissolved chemicals
Give the protein composition of saliva (6)
mucin glycoproteins alpha amylase proline-rich proteins lactoferrin immunoglobulin A lysozyme
Give the 5 main functions of saliva
- prevents dehydration of oral mucosa
- lubrication of mastication and swallowing
- maintaining proper dental hygiene
- assist in digestion of carbohydrates
- act as solvent for taste and smell
Is saliva more or less concentrated than plasma?
More and so is hypotonic
What is the name for the basic unit of a salivary gland?
The Salivon
By which process does the Salivon excrete saliva?
Exocytosis
What is the head of the salivon called?
Acinus
What type of cells does the acinus contain? (shape and classification by function)
Pyramidal-shaped cells serous and mucous cells
What type of cells surround the pyramidal-shaped cells and what are their function?
surrounded by myoepithelial cells which contract and expel the secretions of the exocrine gland
What are the 3 classes of ducts found in the salivon?
- intercalated duct
- striated duct
- excretory duct
(ISE- exercising makes your mouth dry bc of a lack of saliva!)
What are the 2 functions of the ducts in a salivon?
Modify primary secretion
Makes the secretion hypotonic
What can effect the final composition of saliva?
Speed of secretion
Compare the different ratios of serous/mucous cells in the acinus of the 3 salivary glands
Parotid = all serous Submandibular = mostly serous, some mucous Sublingual = mostly mucous, some serous
What nervous system controls salivation?
Autonomic - sympathetic and parasympathetic
Explain the composition of saliva if controlled by SYMPATHETICS
sympathetic = fight or flight so saliva = sticky
Supplied via the periarterial plexus
Explain the composition of saliva if controlled by PARASYMPATHETICS
parasympathetic = rest or digest so saliva = runny
Supplied via the cranial nerves and the parasympathetic SERETOMOTOR NERVE SUPPLY
What are the factors which stimulate salivation? (5)
Smell, taste, nausea, conditional reflexes, pain
What are the factors which inhibit salivation? (5)
Fatigue, sleep, fear, dehydration, exercise
Where do these stimuli get processed?
Medulla
What sort of axons are then triggered?
parasympathetic axons
What are the 2 cranial nerves which control salivation for the parasympathetic nervous system
Facial nerve (VII) Glossopharyngeal nerve (IX)
What are the 3 bilateral pairs of major salivary glands?
Parotid (near ear)
Submandibular (under mandible)
Sublingual (under tongue)
Minor glands - how many and function?
1000s in oral mucosa
basal secretion to keep the mouth moist
Where does the parotid gland/duct drain into the mouth and via what?
Parotid duct drains into the mouth at the 2nd maxillary molar via the parotid papilla
Where does the submandibular gland/duct drain into the mouth?
Via the sublingual caruncle on the floor of the mouth (in midline)
Where does the sublingual gland/duct drain into the mouth?
Via the sublingual fold
What gland secretes 25% of daily saliva?
the parotid gland
What are the 3 contents of the parotid region (vessels which go through the parotid gland)?
- Facial nerve plexus
- Retromandibular vein
- superficial temporal vein
- maxillary vein
- External carotid artery
- superficial temporal artery
- maxillary artery
What part of the parotid gland do the external carotid artery and retromandibular vein go through?
The deep part of the parotid gland
Where does the facial nerve pass through?
past the external carotid artery and retromandibular vein and passes anteriorly on the internal side of the parotid gland
What 2 anatomical features form the medial border of the parotid bed?
- styloid process of the temporal bone
AND
-Stylohyoid and PBD
What forms the posterior body of the parotid bed?
sternocleidomastoid
What forms the anterior body of the parotid bed?
masseter
What form the parotid bed medially and laterally?
Posterior border of the mandibular ramus
Describe the innervation of the parotid gland.
CN IX (glossopharyngeal) –> tympanic plexus –> lesser petrosal nerve –> optic ganglion –> CN V (trigeminal) –> auriculotemporal nerve of CN V3.
What kind of cells is acinus of the submandibular gland
mixture of serous and mucous cells
Where is the submandibular gland located? (2)
In the submandibular triangle and the floor of the mouth
What structure does the submandibular gland wrap around?
The free posterior border of the mylohyoid muscle
Where is the deep portion of the submandibular gland located?
Floor of the mouth
Where is the superficial portion of the submandibular gland located?
on the inferior aspect of the mylohyoid muscle
Between what 2 features does the deep portion of the submandibular gland extend into the floor of the mouth and how far does it extend?
The deep portion of the submandibular gland extends between the body of the mandible and the base of the tongue, as far as the medial aspect of the 2nd molar
What does the submandibular gland continue forward as after the 2nd molar?
The submandibular duct
What to features does the submandibular duct pass through?
Medially = body of the tongue Laterally = sublingual gland
Where does the submandibular gland exit into the floor of the mouth?
Through the sublingual caruncle
Where is the submandibular salivary gland in relation to the mylohyoid ridge/line of the mandible?
Below the mylohyoid ridge/line
Where is the sublingual salivary gland in relation to the mylohyoid ridge/line of the mandible?
Above the mylohyoid ridge/line
What kind of cells is acinus of the sublingual gland
Seromucous (mostly mucous)
What shape are the sublingual salivary glands?
Almond shaped
Where do the right and left glands meet?
Anteriorly to form a hourseshoe shape that surrounds the base of the tongue
Does the sublingual gland have ducts?
YES but they are really small! 12 tiny ducts empty directly upwards through the sublingual fold into the mouth.
Describe the innervation of the the sublingual and the submandibular glands.
CN VII (facial) –> chorda tympani nerve –> CN V3 (trigeminal mandibular) –> lingual nerve –> submandibular ganglion –> submandibular and sublingual glands
What is the clinical diagnosis for a salivary gland stone (salivary calculi)?
Sialolithiasis
What is the clinical diagnosis for dry mouth?
Xerostomia
What are a few causes of Xerostomia?
Salivary calculi
Salivary tumours
Anticholinergic drugs
Sjörgen’s syndrome (saliva-secreting cells destroyed)
