The parotid gland is a bilateral salivary gland located in the face. It produces serous saliva, a watery solution rich in enzymes, which is then secreted into the oral cavity. This salivary secretion lubricates and aids in the breakdown of food. In this article, we shall look at the anatomy of the parotid gland – its location, neurovascular supply, and any clinical correlations.
The parotid gland is a bilateral structure which displays a lobular and irregular shape. It can be divided into deep and superficial lobes, separated by the facial nerve. It lies within a deep hollow, known as the parotid region. The parotid region is bounded superiorly by the zygomatic arch, inferiorly by the inferior border of the mandible, anteriorly by the masseter muscle, and posteriorly by the external ear and sternocleidomastoid.
The secretions of the parotid gland are transported to the oral cavity by the Stensen duct. The duct arises from the anterior surface of the gland, traversing the masseter muscle. It then pierces the buccinator, moving medially, and eventually opens out into the oral cavity near the second upper molar.
The anatomical relationships of the parotid gland are of great clinical importance, particularly during parotid gland surgery. Several important structures pass through the parotid gland: the facial nerve, external carotid artery, and retromandibular vein.
Blood is supplied to the parotid gland by the posterior auricular and superficial temporal arteries. Both these branches arise from the external carotid artery within the parotid gland. Venous drainage is achieved via the retromandibular vein, formed by the unification of the superficial temporal and maxillary veins.
The parotid gland receives both sensory and autonomic innervation. Sensory innervation is supplied by the auriculotemporal nerve (gland) and the great auricular nerve (fascia). The autonomic innervation controls the rate of saliva production. Autonomic innervation has a complex path arising from the glossopharyngeal nerve (CN IX) which synapses with the otic ganglion, a collection of neuronal cell bodies. The auriculotemporal nerve then carries parasympathetic fibres from the otic ganglion to the parotid gland. Parasympathetic stimulation causes an increase in saliva production, while sympathetic innervation originates from the superior cervical ganglion, resulting in vasoconstriction and inhibition of saliva secretion.
The parotid gland is the most common site of a salivary gland tumour. These tumours are usually benign, such as an adenolymphoma. In contrast, tumours of the submandibular and sublingual glands are less common, but more likely to be malignant. Treatment usually involves surgical excision of the tumour and parotid gland, known as a parotidectomy.
The parotid gland, which is located near the second upper molar in the oral cavity, produces secretions that are transported into the mouth through the Stensen duct. This duct originates on the anterior surface of the gland, passing through the masseter muscle and piercing the buccinator before reaching the oral cavity. The anatomical relationships of the parotid gland, which are important for practitioners to understand for parotid gland surgery, include several important neurovascular structures. These include the facial nerve (CN VII), external carotid artery, and retromandibular vein, which is formed within the parotid gland by the convergence of the superficial temporal and maxillary veins.
Blood is supplied to the parotid gland by the posterior auricular and superficial temporal arteries, both branches of the external carotid artery, which arise within the parotid gland itself. Venous drainage of the parotid gland is achieved via the retromandhibular vein, formed by unification of the superficial temporal and maxillary veins.
The parotid gland receives both sensory and autonomic innervation. Sensory innervation is supplied by the auriculotemporal nerve (gland) and the great auricular nerve (fascia). Autonomic innervation of the parotid gland originates from the glossopharyngeal nerve (cranial nerve IX) and synapses with the otic ganglion, from which the auriculotemporal nerve carries parasympathetic fibres to the parotid gland. Parasympathetic stimulation causes an increase in saliva production while increased activity of the sympathetic nervous system, originating from the superior cervical ganglion, inhibits saliva secretion.
Parotid gland tumours are the most common form of salivary gland tumours, with 95% being benign adenolymphomas. Treatment usually involves surgical excision of the tumour and parotid gland, a procedure known as a parotidectomy. During the procedure, it is critical to identify and preserve the facial nerve and its branches, as damage can lead to paralysis of the facial muscles and resulting loss of tone.
Parotitis is the inflammation of the parotid gland, often caused by infection. The pain produced can be referred to as the external ear due to the connection of the auriculotemporal nerve, which provides sensory innervation to both the parotid gland and the external ear.
The parotid gland, located near the second upper molar in the oral cavity, produces secretions that are transported into the mouth through the Stensen duct. Anatomical relationships of the parotid gland are important for parotid gland surgery, as several neurovascular structures, such as the facial nerve, external carotid artery, and retromandibular vein, pass through it. Blood is supplied to the parotid gland by the posterior auricular and superficial temporal arteries, while venous drainage is achieved via the retromandibular vein. The parotid gland receives both sensory and autonomic innervation, from the glossopharygeal nerve, otic ganglion, auriculotemporal nerve, and the superior cervical ganglion. Parotid gland tumours, while often benign, necessitate surgical excision and care to preserve the facial nerve, and parotitis is the inflammation of the parotid gland, often caused by infection.
