SUPERFICIAL AND LATERAL NECK MUSCLES new.pptx

SUPERFICIAL AND LATERAL NECK MUSCLES Neck muscles are a large group of muscles in the cervical area, that are responsible for the movement of the head in all directions. They consists of three main groups of muscles based on their position in the neck; - anterior - lateral - post...

SUPERFICIAL AND LATERAL NECK MUSCLES Neck muscles are a large group of muscles in the cervical area, that are responsible for the movement of the head in all directions. They consists of three main groups of muscles based on their position in the neck; - anterior - lateral - posterior groups  INNERVATION OF THE NECK Cervical Plexus : The Plexus is formed by the anterior rami of cervical spinal nerve C1 - C4. Facial Nerve: It has Eight extra cranial branches: Posterior Auricular Nerve to Posterior belly of digastric Nerve to stylohyoid Five terminal branches : temporal, zygomatic, buccal, marginal mandibular and cervical branches. BRANCHES OF CERVICAL PLEXUS  BLOOD SUPPLY TO NECK External Carotid artery which is a branch of common carotid artery. Thyrocervical trunk: It is a branch of right and left subclavian arteries. It is four branches. - Inferior Thyroid artery - Ascending cervical artery - Transverse cervical artery - Suprascapular artery  ANTERIOR MUSCLES (Superficial Layer) Platysma Description: Platysma is a thin like muscle that lies superficially within the anterior aspect of the neck. Origin: Skin and fascia of infra and supaclavicular regions. Insertion: Lower border of mandible, skin of buccal or cheek region, lower lip, modiolus, orbicularis oris muscle Innervation: Cervical branch of facial nerve (CN VII) Function: Depresses mandible and angle of mouth , tenses skin of the lower face and anterior neck Blood supply: Submental artery (facial artery), Suprascapular artery (thyrocervical trunk)  ANTERIOR MUSCLES (Superficial Layer) Sternocleidomastoid Origin: Sternal Head: Superior part of the anterior surface of manubrium sterni Clavicular Head: Superior surface of medial third of the clavicle. Insertion: Lateral surface of mastoid process of the temporal bone, Lateral half of superior nuchal line of the occipital bone. Innervation: Accessory Nerve (CN XI), branches of the cervical plexus (C2 - C3) Function: Lateral flexion and rotation of the neck when acting unilaterally, and extension of the neck at the atlanto - occipital joints when acting bilaterally. Blood supply: Superior Thyroid artery  ANTERIOR NECK MUSCLES - Suprahyoid muscles: are found superior to the hyoid bone and includes the digastric, mylohyoid, geniohyoid and stylohyoid.They help in elevating the hyoid bone. - Infrahyoid muscles: are found inferior to the hyoid bones and consists of the sternohyoid, omohyoid, sternothyroid and thyrohyoid.They help in  LATERAL NECK MUSCLES Anterior Scalene Muscle Origin: anterior tubercle of transverse processes of vertebrae C3 - C6 Insertion: scalene tubercle of rib 1, superior border of rib 1 Innervation: anterior rami of spinal nerves C4 - C6 Function: Neck Flexion, Neck lateral Flexion, Neck Rotation and elevates Rib 1. Blood supply: Ascending cervical branch of the inferior thyroid artery. Middle Scalene Muscles Origin: posterior tubercle of transverse processes of C3 - C7 Insertion: Superior border of rib 1 Innervation: anterior rami of spinal nerves C3- C8 Function: Neck Lateral Flexion, elevates rib 1 Blood supply: Ascending cervical branch of the inferior thyroid artery. Posterior Scalene Muscle Origin: posterior tubercle of traverse process C4- C6 and C5 - C7 Insertion: external surface of rib 2 Innervation: anterior rami of spinal nerves C6 - C8 Function: Neck lateral flexion, elevates rib 2 Blood supply: Ascending cervical branch of the inferior thyroid artery,superificial cervical artery  SUPERFICIAL MUSCLES (POSTERIOR) Trapezius Origin (descending): medial third of the superior nuchal line, eternal occipital protuberance, nuchal ligament Insertion (descending): Lateral third of clavicle. Innervation: accessory nerve (CN XI) and anterior rami of spinal nerve C3 - C4 (via cervical plexus) Function: elevation of the sacpula while acting with levator scapulae. When acting unilaterally, ipsilateral lateral flexion of the head and neck by acting on atlanto occipital joint and upper cervical vetebrae. Contralateral rotation of the head at the atlantoaxial joint. Bilaterally, extension of the neck. Blood supply: Occipital artery SUPERFICIAL MUSCLES (POSTERIOR) Splenius Capitis Origin: spinous proceses of vertebra C7 - T3 , nuchal ligament Insertion: Lateral superior nuchal line of occipital bone, mastoid process of temporal bone. Innervation: Lateral branches of posterior rami of spinal nerves C2 - C3 Function: Rotates head to the same side. Blood supply: Muscular branches of Occipital artery SUPERFICIAL MUSCLES (POSTERIOR) Splenius Cervicis Description: is a paired back muscle that is found within the prevertebral space of the neck. Origin: spinous process of T3 - T6 vertebrae. Insertion: Transverse processes of C1 - C3 vetebrae Innervation: Lateral branches of posterior rami of lower cervical spinal nerves. Function: rotates head to the same sides. Blood supply: veterbral, occipital, superior intercostal, deep cervical transver cervical arteries.