Parotid Gland Anatomy Tutorial PDF

Tutorial Salivary glands  Parotid gland (Largest salivary gland) Shape: Wedge- shape, (Inverted pyramid) 2 ends: (base upward, apex downward) 3 surfaces 1: lateral, 2: anteromedial, 3: posteromedial). 2 3 1 ...

Tutorial Salivary glands  Parotid gland (Largest salivary gland) Shape: Wedge- shape, (Inverted pyramid) 2 ends: (base upward, apex downward) 3 surfaces 1: lateral, 2: anteromedial, 3: posteromedial). 2 3 1  Zygomatic arch External acoustic meatus masseter Sternomastoid muscle Position of the gland: below the zygomatic arch and external auditory meatus. It extends forwards to the cover the masseter ms& backwards to cover the sternomastoid ms. It extends medially reach to the styloid process. Accessory gland: It is a small detached part lies above the parotid duct. Capsule of the gland: It is enclosed within a capsule of deep cervical fascia called the parotid fascia. The deep layer is thickened between the styloid process and angle of the mandible form the stylomandibular ligament. Capsule of the gland: thickened from the deep wall to form the stylomandibular ligament ( separates parotid from submandibular glands).  Parotid gland Surfaces Borders poles Lateral Anterior Superior Anteromedial Posterior inferior posteromedial medial Superior end base Inferior end apex Parotid duct: 5 cm duct runs forwards from the anterior border below the zygomatic arch pierces the buccal pad of fat, buccopharyngeal fascia, and the buccinator ms. open in the vestibule of the mouth opposite the upper 2nd molar teeth. Superficial ( lateral )surface: related to: Skin, parotid fascia, superficial parotid lymph nodes. Anteromedial surface (3 M) related to: 1- Ramus of the Mandible 2- Masseter muscle 3- Medial pterygoid muscle Posteromedial surface related to 1- Mastoid process and related 2 rmuscles( stenomastoid ms & posterior belly of digastric ms). 2-Styloid process and its muscles. 3-Carotid sheath and its contents ( last 4 cranial nerves, ICA & IJV). Structures within the gland  Structures within the gland 1 1-External carotid artery, Pierces the posteromedial surface, and gives its 2 terminal branches.  Structures within the gland 2 2-Retromandibular vein, descends vertically superficial to the artery.  Structures within the gland 3 3- Facial nerve Pierces the posteromedial surface, runs forward superficial to the vein.  Relations of anterior border Structures passing through anterior border of parotid gland: 1- Temporal branch of facial N. 2-Zygomatic branch 3- buccal branch (upper&lower) 4- marginal mandibular branch 5- Transverse facial artery Relations of apex Structures passing through the lower end of parotid gland: 1-Cervical branch of facial nerve. 2- Anterior and posterior divisions of retromandibular vein  Relations of base - Structures passing through the upper end (base) of parotid gland? 1- Auriculotemporal nerve. 2- Superficial temporal artery. 3- Superficial temporal vein.  Paper & pen open book activity 1.Illustrate lateral view of skull by simple draw 2.Let’s draw point by point Presentation title 26 Surface anatomy of the parotid gland Head of the mandible A D B Center of mastoid process center of masseter m. C 2 cm posteroinferior to angle of mandible  Surface anatomy of the parotid gland Anterior border: line passing downwards and forwards from the head of the mandible (A)to the middle of the masseter(B), the continues downwards and backwards to a point 2cm below and behind the angle of the mandible(C). Upper border: curved line concave upwards from the head of the mandible (A)to the center of the mastoid process (D). Posterior border: straight line between the upper (D) and lower (C) ends.  surface anatomy of parotid duct Middle third of a line extending between the lower border of the tragus and point between ala of nose and the angle of the mouth Arterial supply: Superficial temporal artery. Venous drainage: Retromandibular& External jugular vein. Lymphatic drainage: Superficial& Deep parotid lymph nodes, then into the deep cervical lymph nodes( along internal jugular vein)  Nerve supply pf parotid gland. Sensory Parasympathetic sympathetic 1-Sensory innervation : auriculotemporal nerve. 2-The parasympathetic innervation : **The preganglionic fibers arise from the inferior salivatory nucleus and pass through the glossopharyngeal N then relay in otic ganglion. ** The postganglionic fibers arise from the otic ganglion, and reach the gland through the auriculotemporal N. 3-Sympathetic innervation originates from the superior cervical ganglion, travel along the plexus around the external carotid artery to reach the parotid gland. Nerve supply of parotid gland.  1- Temporalis 1 2-Superficial temporal artery 2 ３ 3-Temporal branch of facial N 4-Auriculotemporal N 4 5 5-Zygomatic branch of facial N 11- Parotid duct 6-Buccal branch of facial N 6 7- Facial Vein 7 8- Parotid gland ８ 9- Facial A. ９ 10-SUBMANDIBULAR GLAND 10 1- Zygomatic 1 - arch 2- Parotid gland 3 3- Parotid duct 2 4- Masseter muscle BM: Buccinator 4 muscle  Ｊ Ｋ Ｚ Z- Facial artery