Parotid Region | Parotid Gland Anatomy | NEET PG | NEXTFELLOW APP | FMGE | USMLE | MBBS | BDS скачать в хорошем качестве

Parotid Region | Parotid Gland Anatomy | NEET PG | NEXTFELLOW APP | FMGE | USMLE | MBBS | BDS

#rajithavanga #rajitha #neet #dental #fmge #mbbs #headandneckanatomy #next #nextfellow #neetpg #usmle #anatomy The parotid gland lies in the fossa which lies posterior to the ramus of the mandible called the retromandibular fossa (parotid bed) • Parotid capsule is formed by the tough investing layer of deep cervical fascia. • This fascia splits in the region between the angle of the mandible and the mastoid process to enclose the gland. • The superficial lamina is thick, strong, unyielding, and adherent to the gland while deep lamina is thin. • The superficial lamina blends with the epimysium of masseter to form a thick parotido-masseteric fascia, which is attached above to the zygomatic arch. • The thin deep lamina is attached to the tympanic plate and styloid process of the temporal bone; • It is separated from the submandibular gland by a facial extension and the stylomandibular ligament, which extends from the styloid process to the angle of the mandible. (Therefore, pus does not readily exchange between these two glands.)  Infection of the parotid gland: The parotid gland is commonly infected by the mumps virus causing inflammation and swelling of the gland (mumps).  The parotid swellings are very painful due to the unyielding nature of the parotid capsule, any inflammation or tension within the parotid gland will cause severe pain Relations of the parotid gland  The anteromedial Surface is deeply grooved by the posterior border of the ramus of the mandible covering muscles and the lateral aspect of the temporomandibular joint.  Postero medial surface is molded onto the mastoid and styloid processes and their covering muscles. The styloid process separates the gland from the internal carotid artery, internal jugular vein, and last four cranial nerves.  Superficial Surface covered from external to deep by skin, superficial fascia containing anterior branches of the greater auricular nerve, superficial parotid (preauricular) lymph nodes, platysma, parotid fascia, and deeper parotid lymph nodes. Three main structures traverse the gland from superficial to deep these are: 1. Facial nerve. 2. Retromandibular vein. 3. External carotid artery. Patey’s Faciovenous Plane: • The parotid gland is divided into large superficial and small deep parts or lobes. • These lobes are connected by the isthmus of the glandular tissue, so that the gland appears H-shaped in coronal section. • The branches of facial nerve pass forward through the isthmus. • The plane between the superficial and deep lobes in which nerves and veins lie has been designated as Patey’s faciovenous plane. This plane helps the surgeons to remove the parotid tumor without damaging the nerve. Stensen’s parotid duct crosses the masseter, pierces the buccinator muscle, buccopharyngeal fascia, buccal pad of fat and opens into the vestibule of the oral cavity opposite the upper second molar tooth. 1. Parasympathetic (secretomotor) supply: It is provided through auriculotemporal nerve. • The preganglionic fibres arise from the inferior salivatory nucleus in the medulla and pass successively through glossopharyngeal nerve, tympanic branch of glossopharyngeal (Jacobson’s nerve), tympanic plexus and lesser petrosal nerve to relay into otic ganglion. • Postganglionic fibres arise from the cells of the ganglion and pass through the auriculotemporal nerve to supply the parotid gland. The stimulation of parasympathetic supply produces watery secretion. 2. Sympathetic supply: It is derived from sympathetic plexus around external carotid artery formed by postganglionic fibres derived from superior cervical sympathetic ganglion. The preganglionic sympathetic fibres arise from the lateral horn of T1 spinal segment. The sympathetic fibres are vasomotor and their stimulation produces thick sticky secretion. 3. Sensory supply: It is derived from: (a) Auriculotemporal nerve. (b) Great auricular nerve (C2 and C3). The C2 fibres are sensory to the parotid fascia.