Head and Neck 9: Salivary Glands

• The parotid gland is the largest salivary gland and secretes serous saliva
• The parotid gland lies on the surface of the masseter in front of the auricle, and its posterior base wraps around the ramus of the mandible and extends towards the styloid process
• The parotid gland transmits saliva through the parotid duct (duct of Stensen), which travels on the surface of the masseter and pierces the buccinator and buccal fat pad to reach the buccal mucosa, opening adjacent to the maxillary second molar
• The main trunk of the facial nerve, external carotid artery, and retromandibular vein emerge from the parotid gland
• External carotid artery divides into the superficial temporal and maxillary artery within the parotid gland
• Parotid gland is innervated by the auriculotemporal nerve (which is also inside the parotid gland)
• Parasympathetic innervation increases salivation
• Sympathetic innervation decreases salivation
• Parasympathetic innervation of the parotid gland: glossopharyngeal nerve → tympanic nerve → tympanic plexus → lesser petrosal nerve → otic ganglion → auriculotemporal nerve → parotid
• Sympathetic innervation of the major salivary glands: thoracic spinal nerves → superior cervical ganglion → periarterial sympathetic nerves → gland
• The submandibular gland is the second largest gland and produces the majority of the saliva; it is a mixed gland producing seromucous saliva
• The submandibular gland is C-shaped with one part lying inside the floor of the mouth, and the other lying in the anterior triangle of the neck
• The submandibular gland transmits saliva through the submandibular duct (duct of Wharton) that eventually crosses the lingual nerve and opens into the sublingual papilla, near the base of the lingual frenulum
• The submandibular gland is innervated by the lingual nerve from the trigeminal mandibular nerve
• Parasympathetic innervation of the submandibular and sublingual gland: facial nerve → chorda tympani → lingual nerve → submandibular ganglion → gland
• The sublingual gland is the smallest of the major glands and produces mucous saliva
• The sublingual gland lies on the floor of the mouth, in between the mylohyoid, mandible, sublingual mucosa and tongue, and it is covered by the sublingual fold
• The sublingual gland gland releases 7-15 small ducts (ducts of Rivinus) that open directly into the surface of the sublingual fold
• Occasionally, the sublingual gland has a larger duct (duct of Bartholin) that opens into the sublingual papilla near the base of the lingual frenulum
• The sublingual gland is innervated by the lingual nerve
• An important group of minor glands is Von Ebner’s glands, which are adjacent to the vallate papillae of the tongue; they not only produce saliva but are also important for taste sensation