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THE NECK

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. The neck (L. collum, cervix) is the transitional area between the head superiorly and the clavicles inferiorly that joins the head to the trunk and limbs.

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2. It serves as a major passage for structures passing between them.3. In addition, several important organs with unique functions are located here: the larynx and the thyroid and parathyroid glands, for example.

Skin of the neck (cutaneous nerves)

Great occipital nerve (C2)

Lesser occipital nerve (C2)

Great auricular nerve (C2,C3)

Transverse cutaneous nerve (C2,C3)

Supraclavicular nerves (C3,C4)

Superficial fascia

Platysma muscle

External jugular vein

Superficial veins

Tributaries of E.J.V and ant. J.V.

Cervical lymph node

Deep cervical fascia

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Sternomastoid muscle

Major muscles of the neck

Important notesLayers of deep cervical fascia: investing

layer, pretracheal, prevertebral and carotid sheath

Investing layer of deep fascia encloses sternomastoid and trapezius muscles

Contents of carotid sheath: CCA and ICA, IJV and vagus nerve

N.B: all parts of skin of face and scalp infront of the ear innervated by trigeminal nerve except area over the angle of the mandibule and parotid gland innervated by great auricular nerve

Important veins1. external jugular veinBegin: just behind angle of the mandible

by union of posterior auricular vein and post.division of the retromandibular vein

End: drain into subclavian veintributaries 1. post.external jugular vein2. ant. Jugular vein

Important veins2. internal jugular vein

Begin: as contiuation of sigmoid sinus and leave skull throught jugular foramen

End: join subclavian vein to form brachiocephalic vein

Tributaries: 1. facial vein2. Lingual vein3. Pharyngeal vein4. Thyroid veins

Sternomastoid muscleOrigin : a) Sternal head: Rounded and tendinous from front of manubrium.b) Clavicular head: Thin and fleshy from upper surface of med. ⅓ ofclavicle.Insertion : Mastoid process and lateral ⅓ of the superior nuchal line.Action : 1- Unilateral contraction → directs the face to opposite side.2- Bilateral contraction → tilt the head backwards.Nerve Supply : → spinal accessory n.* Injury to the muscle leads to it contracture and shortening → Torticollis.The oblique position of the sternomastoid divides the side of the

neck into anterior and posterior triangle.

A note about the scalene muscles :Scalenus anteriorScalenus mediusScalenus posteriorOrigin : transverse processes of cervical vertebrae .Insertion : first and second ribs .Action : 1- Lateral flexion of neck .2- Fixation of ribs during forced inspiration .Nerve supply : cervical and brachial plexuses .. The subclavian vein passes infront the of scalenus anterior . The subclavian artery and brachial plexus pass between

scalenus anterior and scalenus medius .