In this week’s anatomy session we looked at the 3 pairs of salivary glands: sublingual, submandibular and parotid glands. We noted their locations, nearby structures, how they duct into the oral cavity and their nervous innervation. You can review this in your favourite anatomy textbook. Remember that these glands are encapsulated in connective tissue, causing pain on swelling of the parotid glands with mumps.
Remember that these glands receive parasympathetic autonomic innervation to instruct the cells to secrete saliva. The sublingual and submandibular glands receive this innervation from the facial nerve, also known as CN VII. The nerves leave the facial nerve in a fine nerve called the chorda tympani, pass to the lingual nerve, join it and pass beneath the tongue and floor of the mouth and reach the glands there. The parotid gland receives parasympathetic innervation from the glossopharyngeal nerve (CN IX). (Fibres from this nerve pass via the otic ganglion, by the way).
Interestingly the facial nerve passes through the parotid gland on its way to innervating the muscles of facial expression, but doesn’t innervate the gland itself. Within the gland the nerve splits into 5 branches: temporal, zygomatic, buccal, marginal mandibular and cervical.
Also within the region of the parotid gland the external carotid artery splits into the maxillary and superficial temporal arteries. The retromandibular vein draining blood from the deep parts of the face forms here, and will drain to the jugular veins. So the parotid gland is an important landmark and is used for locating a number of structures.
MedlinePlus & salivary gland disorders (lots of links on this page).
Glands of the GI system – serous or mucous?
