Anterior triangle part 2
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The document describes the anatomy of structures in the submandibular region of the neck, including muscles, salivary glands, nerves and vessels. It discusses the digastric muscle, mylohyoid muscle, stylohyoid muscle, geniohyoid muscle, genioglossus muscle, hyoglossus muscle, submandibular gland, sublingual gland and lingual nerve. Relationships between these structures are defined, along with origins, insertions, nerve supply and actions of the muscles.
Anterior triangle part 2
- 2. Digastric Muscle Stylohyoid Posterior belly of digastric Anterior belly of digastric Origin : arises by two bellies 1. Anterior belly : from the digastric fossa on the lower border of the mandible close to the symphysis menti. 2. Posterior belly : from the mastoid notch on the medial side of the mastoid process Insertion : into the intermediate tendon which is attached to the hyoid bone by a fibrous bully. Nerve supply : 1. Anterior belly : by nerve to mylohyoid (from the mandibular) because it develops from the first branchial arch. 2. 2. Posterior belly : from the facial nerve because it develops from the second branchial arch. Actions : 1. Depresses the mandible 2. 2. Elevates the hyoid bone Mylohyoid Mohamed el fiky
- 3. 1. Mastoid process with sternomastoid. 2. Parotid gland : between the mastoid process and the angle of the mandible. 3. Angle of the mandible. 4. Submandibular salivary gland. Superficial relations of post. Belly of digastric Mohamed el fiky
- 4. Deep Relations of the Posterior Belly of digastric a. Three big vessels : 1. Internal carotid artery 2. External carotid artery. 3. Internal jugular vein b. Three cranial nerves : 1. Vagus : lies between the internal jugular vein and the inter carotid artery (posteriorly). 2. Hypoglossal : between the internal jugular vein and the into carotid artery 3. Accessory nerve : between the muscle and the internal jugular vein (C) Along its upper border : 1. Posterior auricular artery 2. 2. Stylohyoid muscle (D) Along its lower border 1. Occipital artery 2. Hypoglossal nerve Mohamed el fiky
- 5. Stylohyoid Site: lies along the upper border of the posterior belly of digastric Origin : posterior surface of styloid process. Insertion : body of the hyoid bone at its junction with and the greater cornu. Nerve supply : facial nerve Actions : pulls the hyoid bone upwards and backwards Note : its tendon is perforated by the intermediate tendon of the digastric muscle Stylohyoid Muscle Mohamed el fiky
- 6. Mylohyoid Muscle The two mylohyoids form the floor the floor of the mouth (oral diaphragm). Origin : mylohyoid line of the mandible. Insertion: 1.Posterior one-fourth of fibers: into the body of the hyoid bone. 2. Anterior three – fourths of fibers : into the median raphe which extends 3.from the symphysis menti to the hyoid bone Nerve supply : mylohyoid nerve. Actions: 1. elevation of floor of the mouth in the first stage of deglutition 2. depression of the mandible. 3. elevation of the hyoid bone Mohamed el fiky
- 7. 2- Muscles 3- Glands 4- Vessels1- Skin and Fascia Platysma Anterior Belly of Digastric Submandibular Lymph Nodes Superficial Part of Submandibular Gland Submental and Myelohyoid Vessels 1- Superficial Relations of mylohyoid 1. anterior belly of digastric 2. superficial part of the submandibular salivary gland 3. mylohyoid nerve and vessels 4. submental vessels and lymph nodes. Mohamed el fiky
- 8. 1- Glands Sublingual GlandDeep Part of Submandibular Gland and its Duct 2- Nerves ligual Nerve and Submandibular Ganglion Hypoglossal Nerve 3- Muscles Hyoglossus Geniohyoid Genioglossus Styloglossus 2- Deep Relationsof mylohyoid b) Deep relations: 1) Hyoglossus muscle : with the following structures intervening between it and the mylohyoid: a) Styloglossusmuscle b) Lingual nerve and submandibular ganglion. c) Submandibularganglion d) Deep part of submandibular gland and its duct e) Hypoglossalnerve: 2) Genioglossus muscle : anterior to the hyoglossus. 3) Sublingual salivary gland : on the lateral surface of the genioglossus Mohamed el fiky
- 9. Hyoglossus Muscle Origin : body and greater cornu of the hyoid bone. Insertion : posterior half of the side of the tongue. Nerve supply : hypoglossal nerve Actions : depression of the tongue. (A) Superficial (lateral) relations: a. overlapped by the mylohyoid muscles b. structures intervening between the mylohyoid and hyolossus are as follows from above downwards 1.Styloglossus muscle 2.Lingual nerve 3.Submandibular ganglion : suspended from the lingual nerve by 4.two roots. 5.Deep part of submandibular gland and its duct. 6.Hypoglossal nerve and vena comitans hypoglossi. 7.Suprahyoid branch of the first part of lingual artery. Mohamed el fiky
- 10. 4. Glossopharyngeal nerve. 1. Genioglossus muscle. 2. Middle constrictor muscle of pharynx. 6. Lingual artery. 5. Stylohyoid ligament. 3. Inferior longitudinal muscle of the tongue. (B) Deep ( medial) relations of hyoglossus: 1- Genioglossus 2- Middle constrictor of pharynx 3- Glossopharyngeal nerve 4- Stylohyoid ligament 5- Lingual artery. (C) Structures passing deep to the posterior border of hyoglossus : from above down are: 1. Glossopharyngeal nerve 2. stylohyoid ligament 3. lingual artery. Mohamed el fiky
- 12. Geniohyoid Muscle Origin : inferior genial tubercle Insertion : anterior surface of the body of the hyoid bone Nerve supply : C1 through the hypoglossal nerve. Actions: u Elevates the hyoid bone v Depresses the mandible when the hyoid bone is fixed Geniohyoid Muscle Mohamed el fiky
- 13. Genioglossus Muscle Shape : fan – shaped ; forms the main bulk of the tongue. Origin : from the superior genial tubercle of the mandible Insertion : into the tongue. Nerve supply : hypoglossal nerve. Actions: 1. acting alone: pulls the tongue forwards to the opposite side. 2. with its fellow of the opposite : protrude the tongue Mohamed el fiky
- 14. Submandibular Gland Superficial part Deep part Mylohyoid muscle Parotid Submandibular Gland Size : about the size of walnut Parts: the gland is divided into 2 parts : (A) Superficial part : is large and lies superficial to the mylohyoid muscle (B) Deep part : is small and lies deep to the mylohyoid muscle. The two parts are continuous with each other around the posterior border of mylohyoid muscle. Mohamed el fiky
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- 16. Superficial part Deep part Body of Mandible Mylohyoid muscle Facial artery Facial vein The superficial part of the submandibular gland Superficial part has has 3 surfaces a. Inferolateral b. Lateral c. Medial 1) Inferolateral surface : related to : a. Skin b. Platysma c. Cervical branch of the facial nerve d. Deep fascia e. Facial vein. f. Submandibular lymph node 2) Lateral surface : is related to : a. Submandibular fossa below the mylohyoid line. b. Insertion of medial pterygoid c. Facial artery. 3) Medial surface: Anterior part : is related to the mylohyoid muscle from which it is separated by the submental vessels , mylohyoid nerve and vessels. Ø Posterior part : is related to the hyoglossus muscle from which it is separated by the following structures : 1- Stryloglossus muscle. 2- Lingual nerve and submandibular ganglion 3- Hypoglossal nerve 4- Suprahyoid artery. Lingual nerve Lingual artery Lingual vein Mylohyoid muscle Mohamed el fiky
- 17. Hypoglossal nerve Lingual nerve Deep Part of Submandibular Gland Genioglossus Sublingual Gland Deep Part of The Submandibular Gland Extends forwards in the interval between the mylohyoid and the hyoglossus Relations: Laterally : mylohyoid muscle Medially : hyoglossus muscle Above : lingual nerve and submandibular ganglion Below : hypoglossal nerve. Submandibular duct: • Is about 5cm long • Emerges from the anterior end of the deep part of the gland • Runs forwards on the hyoglossus under cover of the mylohyoid • It then runs between the sublingual gland and the genioglossus muscle • where the lingual nerve crosses lateral and then hooks below it opens in the floor of the mouth , on the summit of the sublingual papilla at the side of the frenulum of the tongue Mohamed el fiky
- 18. Nerve Supply of the Submandibular Gland Nerve supply: 1. Sensory supply : from the lingual nerve. 2. Sympathetic : from the sympathetic plexus around the facial artery 3. Parasympathetic (secretomotor): from the chorda tympani branch of facial along the lingual nerve Arterial supply: from the facial and lingual arteries Venous drainage : into the common facial or lingual veins Lymphatic drainage : into the submandibular lymph nodes Mohamed el fiky
- 19. Floor of the Mouth Mylohyoid Muscle Deep Part of Submandibular Gland Genioglossus Ligual Nerve Submandibular Duct Sublingual Salivary Gland Site : located in the floor of the mouth between the mucous membrane and the Mylohyoid muscle occupying the sublingual fossa of the mandible. Shape : almond – shaped Size : is the smallest of the three main salivary glands , 3 to 4 gm in weight Relations : Superiorly : mucous membrane of the floor of the mouth which is raised by the gland to of form the sublingual fold . Inferiorly : mylohyoid muscle Medially : genioglossus muscle , lingual nerve and submandibular duct Laterally : sublingual fossa of the mandible Ducts : 8-20 ducts come out of the gland to open into the floor of the mouth on the summit of the sublingual fold. Arterial supply : sublingual and submental arteries Venous drainage : lingual and facial veins Lymphatic drainage : submental and submandibular lymph nodes Nerve supply supply: same as that of the submandibular gland Mohamed el fiky
- 21. The Lingual Nerve Course in the submandibular region : Ø Runs on the lateral surface of the hyoglossus deep to the mylohyoid muscle. Ø Finally it passes between the genioglossus and the sublingual gland. Here it hooks around the submandibular duct and divides into branches. Distribution : u Carries general senation from the anterioir two-thirds of the tongue and the floor of the mouth. v The chorda tympani branch of the facial nerve which is secretomotor (parasympathetic) to the submandibular and sublingual salivary gland and gustatory to the anterior 2/3 of the tongue is also distributed through Chorda Tympani Inferior Alveolar nerve Lingual nerve Mohamed el fiky
- 23. Submandibular Ganglion Submandibular Ganglion Site : lies on the hyoglossus muscle where it is suspended from the lingual nerve by two roots. Roots : 1. Sensory root : from the lingual nerve (passes without relay). 2. Sympathetic root : from the plexus around the facial artery (passes without relay). 3. Parasympathetic (motor) root: • The preganglionic fibers arise from the superior salivary nucleus in the pons and pass successively through the facial nerve , chorda tympani and lingual nerves to relay in the ganglion. • The postganglionic secretomotor fibers supply the submandibular and the sublingual glands. Mohamed el fiky
- 24. Thank You