Transcript Anterior triangle of the neck
Katerina Kyprianou
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Muscles
SCM ◦
Arteries
Carotid arteries ◦
Veins
IJV ◦
Nerves
Vagus
Anterior boundary: ◦ Median line of the neck Posterior boundary: ◦ Anterior bordrer of the SCM Superior boundary: ◦ Inferior border of the mandible Apex: ◦ Jugular notch Roof: ◦ platysma Floor: ◦ Pharynx , larynx, thyroid gland
Attachments: Origin ◦ ◦ ◦ mastoid process of temporal bone Superior nuchal line Insertion Sternal head ◦ Anterior surface of manubrium Clavicular head ◦ ◦ Superior surface of medial 1/3 of clavicle Innervation Spinal accessory nerve (motor) C2 & C3
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Unilateral contraction
Tilts head to the same side Rotates head so that head is turned superiorly to the other side
Bilateral contraction
Extends neck (antlanto-occipital joints) Flexes superior cervical vertebrae Extends superior cervical vertebrae while flexing inferior vertebrae - chin is thrust forward Elevate manubrium & medial end of clavicles – assisting in respiration
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Common carotid artery Internal jugular vein
Located more laterally
Vagus nerve
Located posteriorly
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Common carotid
Right: begins at bifurcation of brachiocephalic trunk Left: arises as left common carotid from aorta Bifurcates at level of: thyroid cartilage
External carotid ◦ Supply most of structures external to cranium ◦ ◦ ◦ Runs: between neck of mandible and & lobule of auricle Embedded in parotid gland Terminal branches: superficial temporal & maxillary aa Internal carotid ◦ Direct continuation of common carotid ◦ ◦ ◦ ◦ No branches in neck Enter cranium through carotid canals – main arteries of the brain Carotid sinus – proximal part of internal carotid Carotid body – between internal & external
Largest vein in neck Drains blood from: anterior face, cervical viscera & deep muscles of the neck Begins at: jugular foramen as a continuation of the sigmoid sinus
◦ Runs inferiorly through the neck in the carotid sheath Leaves the anterior cervical region by passing deep to the SCM Unites with the subclavian to form the brachiocephalic Posterior to the sternal end of the clavicle
Exit cranium through jugular foramen Pass through the carotid sheath Right vagus: Passes anterior to the first part of the subclavian aa and posterior to the brachiocephalic vein ans SC joint to enter the thorax Left vagus: descends between left common carotid & left subclavian aa & posterior to SC joint to enter thorax
Arise from the vagus nerves R & L have the same distribution but recur over different structures Right: loops inferior to the right subclavian aa Left: Loops inferior to the arch of the aorta Both ascend superiorly