Salivary glands and pathologies

Gleeting involves the mouth, tongue, and subma...
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There are three pairs of salivary glands,one on either side.

Parotid gland

Largest SG,predominantly serous secretion

Parotid duct/Stenson’s duct -Opens opposite to upper second molar tooth.

Secretion of saliva by the parotid gland is controlled by presynaptic parasympathetic fibres originating in the inferior salivatory nucleus; these leave the brain via the tympanic nerve branch of glossopharyngeal nerve (CN IX), travel through the tympanic plexus (located in the middle ear), and then form the lesser petrosal nerve until reaching the otic ganglion. After synapsing in the Otic ganglion, the postganglionic (postsynaptic) fibers travel as part of the auriculotemporal nerve (a branch of the mandibular nerve (V3)) to reach the parotid gland.

Sympathetic nerves originating from Superior Cervical Ganglion and giving rise to the external carotid nerve plexus reach the gland by traveling along the external carotid arterial branches.

Parasympathetic stimulation produces a water rich, serous saliva. Sympathetic stimulation leads to the production of a low volume, enzyme-rich saliva. This is done by vasoconstricting the blood supply to the parotid gland reducing the potential for water collection. There is no inhibitory nerve supply to the gland.The most common of tumors in the parotid gland are benign and only affect the superficial gland. These include pleomorphic adenoma and Warthin’s tumor.

Submandibular gland

Account for 80% of saliva

80% of calculi occur in Submandibular gland,due to predominantly mucous secretion.

Lying superior to the digastric muscles, each submandibular gland is divided into superficial and deep lobes, which are separated by the mylohyoid muscle:

  • The superficial portion is larger. The mylohyoid muscle runs below it.
  • The deep portion is smaller.

Secretions are delivered into the Wharton’s ducts on the superficial portion after which they hook around the posterior edge of the mylohyoid muscle and proceed on the superior surface laterally. The ducts are then crossed by the lingual nerve, and ultimately drain into the sublingual caruncles on either side of the lingual frenulum along with the major sublingual duct (Bartholin).

  • Parasympathetic innervation to the submandibular glands is provided by the superior salivatory nucleus via the chorda tympani, a branch of the facial nerve that synapses in the submandibular ganglion after which it follows the Lingual nerve leaving this nerve as it approaches the gland. Increased parasympathetic activity promotes the secretion of saliva.
  • The sympathetic nervous system regulates submandibular secretions through vasoconstriction of the arteries that supply it. Increased sympathetic activity reduces glandular bloodflow, thereby decreasing salivary secretions and producing an enzyme rich mucous saliva.

Submandibular/Submaxillary/Wharton’s duct-Opens on either side of frenulum(Lingual N is a relation)

Sublingual glands

Lies on the floor of mouth just beneath the mucosa

  1. Sublingual ducts/Ducts of rivinus-8-20 in number
  2. Largest duct of Sublingual gland is-Sublingual duct/Bartholins duct, joins submandibular duct.
  3. The chorda tympani nerve (from the facial nerve via the submandibular ganglion) is secretomotor to the sublingual glands.

Ranula

  1. Extravasation cyst of Sublingual salivary gland
  2. Cystic translucent lesion which lies on side of midline

Sublingual dermoid is a midline opaque lesion

Plunging ranula-Descends into the neck by decussating fibres of myelohyoid muscle.

Treatment-Excision of ranula along with Sublingual salivary gland.

Submandibular duct and Lingual nerve can be damaged during Ranula surgery.

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