DR. MURAD H KAZI Muscluar triangles of ……………….the neck

POSTERIOR TRIANGLE BOUNDARIES Trapezius muscle Sternomastoid muscle clavicle

POSTERIOR TRIANGLE Boundaries: - In front → Posterior border of sternomastoid m. - Behind → Anterior border of trapezius m. - Apex → Middle ⅓ of superior nuchal line. - Base → Middle ⅓ of the clavicle. Roof - Skin. - Superficial fascia. - Deep (investing) fascia of the neck. The superficial fascia of the posterior triangle contains the following : (1) Platysma m. : (a subcutaneous m.) (2) External Jugular vein (3)The cutaneous branches of the cervical plexus Floor: From below upwards: a) Scalenus medius. b) Levator scapulae. c) Splenius capitis.

Contents: Arteries 1- Third part of subclavian a. 2- Suprascapular a. 3- Superficial (or transverse) cervical a. 4- Occipital a. (near the apex). Veins 5- Subclavian v., receiving its only tributary, the external jugular v. Nerves 6- Roots and trunks of brachial plexus. 7- Spinal accessory n. (runs on levator scapulae). L.Ns. 8- Occipital L.N. (at the apex with the occipital a.). 9- Supraclavicular L.N. (at base with the subclavian a.). Ms. 10- Inferior belly of omohyoid.

OMOHYOID MUSCLE

DIVISION OF POSTERIOR TRIANGLE Occipital triangle Supra clavicular

ANTERIOR TRIANGLE

□ Boundaries : Anteriorly → Middle line of the neck. Posteriorly → Ant. border of sternomastoid. Base (above) → Lower border of mandible. Apex (below) → Suprasternal notch. □ Roof: 1- Skin. 2- Superficial fascia (+ its contents). 3- Investing ( deep ) fascia. Contents of the Superficial Fascia of the Roof: a- Platysma muscle. b- Transverse cervical n. c- Anterior jugular v. : It is formed by the union of the submental veins → descends in the superficial fascia near the middle line → pierces the deep fascia above the sternum → passes deep to the sternomastoid → ends in the external jugular v. The deep parts of both anterior jugular veins are connected together by jugular arch. □ Subdivisions : 3 ½ triangles. See the table.

DIGASTRIC MUSCLE

Suddivisions of ANTERIOR TRIANGLE

Suprahyoid muscles 1-MYLOHYOID MUSCLE Mylohyoid line

2- stylohyoid muscles 3- geniohyoid Inferior mental spine

The suprahyoid muscles the muscles of the floor of the mouth Recall of relevant structures

Infrahyoid muscles

Enumerate main contents of submandibular triangle and give short account on one of them 1. Muscles: suprahyoid muscles (mylohyoid muscle), geniohyoid, stylohyoid, digastric and hyoglossus muscles 2. Glands: submandibular salivary glands & L.N. 3. Nerves: nerve to mylo-hyoid muscle, hypoglossal nerves and Submandibular ganglion 4. Vessels: facial artery& vein

Enumerate main contents of submandibular region and give short account on one of them 1. Muscles: 1:suprahyoid muscles (mylohyoid muscle), geniohyoid, stylohyoid, digastric and hyoglossus muscles 2:genioglossus 1. Glands: submandibular salivary glands & L.N. Sublingual salivary gland 1. Nerves: nerve to mylo-hyoid muscle, hypoglossal nerves and Submandibular ganglion Lingual nerve 1. Vessels: lingual & facial vessels

Facial vessels Submandibular ganglion Lingual nerve Sublingual salivary gland Hypoglossal nerve Lingual vessels Nerve to mylohyoid muscle Submandibular salivary gland

MuscleOrigineInsertionNerve supplyaction Digastric musclepost. belly: Mastoid process of temporal bone ant. belly: Body of mandible Intermediate tendon is held to hyoid by fascial sling post. belly: facial nerve ant belly: nerve to mylohyoid Depresses mandible or elevates hyoid bone Mylohyoid muscleMylohyoid line of body of mandible Body of hyoid bone and fibrous raphe Inferior alveolar nerveElevates floor of mouth and hyoid bone or depresses mandible Hyoglossus muscleHyoid bonePost. ½ of the side of the tongue Hypoglossal nerveDraw the tongue downwards and help suckling GeniohyoidGenial tubercle of the mandible Body of hyoid boneHypoglossal nerveDepresses mandible or elevates hyoid bone StyloyoidStyloid processHyoid boneFacial nerve with post. Belly of digastric Elevate hyoid bone suprahyoid muscles

Enumerate main contents of carotid triangle and give short account on one of them 1. Carotid sheath: CCA, ICA, IJV and vagus nerve 2. External carotid artery 3. Hypoglossal nerve 4. Ansa cervicalis 5. Accessory nerve 6. Sympathetic trunk

ANSA CERVICALIS It is a nervous loop situated in front of the carotid sheath. It is formed by union of 2 limbs : A) Superior limb : Descending from the hypoglossal n. and containing fibers of C1 spinal nerve. B) Inferior limb : From C2 and C3 spinal nerves. Branches : arise from the tip → supply all infrahyoid muscles (near their lower ends) except thyrohyoid.

Enumerate main contents of muscular triangle and give short account on one of them Infra hyoid muscles

Enumerate main contents of submental triangle and give short account on one of them 1. Submental LN 2. Anterior jugular vein