Superficial and lateral muscles of the neck

1- Platysma - in the subcutauous tissue - thickness is few millimeter - external jugular vein - cutanous nerve of neck deep to it. - tense the skin releasing pressure on superficial vein - men use this muscle when shaving their neck

2- Sternocleidomastoid (SCM): - is key muscle (landmark) in neck - has two head : * sternal head * clavicular head - attach to : * mastaid process * superior nuchial line. - innervated by : * spinal root of accessory n. (motor) * C2,C3,(pain, and proprioception). - acting by tilt head to one side i.e laterally flexes neck and rotate it so face is turned superiorly toward opposite side. - acting together two muscle flex the neck so chin is thrust forward.

Trapezius:- - cover posterolateral aspect of neck and thorax. it is superficial muscle of back. - its superior attachment is to:- - medial 1,3 of superior nuchial line. - external occipital protuberance. - ligamentum nuchae. - spinous process of C7-T3 vert. - lumber and sacral spinous process. - its inferior attachment is to:- - lateral 1,3 of clavicle. - acromion, and spine of scapula

- its innervation by :- Of accessory nerve (motor) and C3,C4 nerve ( pain,proprioception). - its main action is:- - elevation, rctraction, rotates, scapula. - superior fiber elevate scapula. Middle fiber retract scapula. Inferior fiber depress scapula. Torticollis :- Flexion deformity of neck: - congenital - spasmodic

Triangles of the neck:- Divided by SCM muscle into:- Anterior, Posterior T. * Posterior T. :- Anterior post. Border of SCM Posterior Ant. Border of trapezius. Inferiorly middle 1,3 of clavicle between SCM and (base) trapezius. Apex where SCM and trapezius meet on superior nuchial line. Roof *skin. *superficial fascia. * platysma. * investing layer of deep cervical fascia

Floor * prevertebral fascia. * semispinalis capitis. * splenius capitis. * levator scapula. * scalenus medius, posterior, small part of scalenus anterior. * muscles covered by the prevertebral layer of deep cervical fascia.

* Post. T. divided in to:- - supraclavicular (subclavian) T. - occipital T.. by inferior belly of omohyaid muscle. * Occipital T. (superior large):- - part of external jugular vein. - accessory nerve. - posterior branches. - cervical plexus. - trunk of brachial plexus. - transverse cervical artery. - cervical L.N. - occipital a. in its apex. * Supraclavicular T. (small) inferior subclavian T. - subclavian a. - part of subclavian vein. - suprascapular a. - supraclavicular L.N.

Contents of post. T.:- - Arteries:- - subclavian a. (3 rd part) - transverse cervical a.(Superficial,deep) - suprascapular a. - occipital a. - Veins:- - external jugular vein.(EJV)* ----subclavian v. Receive transverse cervical v. Suprascupular Anterior jugularv. * (EJV):- is usually visible above clavicle for only a short distance. when venous plessure rise vein become prominent this seen in:- - heart failure. - obst. Of superior vena cava by tumor cells. - enlarged supraclaviular L.N. - increased intrathorasic pressure.s.

Nerves: 1- accessory nerve. 2- ventral rami (root of brachial plexus) 3- ventral rami of cervical plexus.

* cutanous branches of cervical plexus are(nerve point of neck) 1- lesser accipital nerve(C2) - posterior to auricle 2- Great auricular nerve ( C2, C3) - paratid gland - post. Aspect of auricle - angle of mandible 3- Transverse cervical nerve (C2,C3) - cross SCM supply - anterior D. deep to platysma 4- Supraclavicular nerve (C3,C4) - common trunk, supply skin over neck and skin over shoulder

Lymph node in post. D - superficial cervical L.N. EJV - Deep cervical L.N. IJV * Supra clavicular L.N. which enlarged in carciuoma of brest T.B., Hodgchin's disease * occipital L.N.