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Flashcards in Posterior Trisngle Of The Neck Deck (68)
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Skin of the back of the neck and scalp innervated by

Dorsal rami of spinal nerves C2-C5


Skin of anterior and lateral aspects of neck are innervated by

Ventral rami of C2-C4 spinal nerves via cutaneous branches of cervical plexus


Where do the ventral rami of C2-C4 spinal nerves emerge from?

Underneath posterior border of sternocleidomastoid muscle


What does the ventral rami of C2-C4 spinal nerves via the cutaneous branches of the cervical plexus supply?

Skin of anterior and lateral aspects of the neck


What are the cutaneous branches of cervical plexus?

-Lesser occipital nerve (C2 or C2, C3)
-greater auricular nerve (C2, C3)
-transverse cervical nerve (C2, C3)
-supraclavicular nerves (C3, C4)


Lesser occipital nerve

-cutaneous branch of cervical plexus
-C2 or C2, C3
-follows posterior border of sternocleidomastoid
-supplies skin over lateral part of accipital region and upper part of medial surface of auricle


greater auricular nerve

-cutaneous branch of cervical plexus
-C2, C3
-ascends superficial to sternocleidomastoid, parallel to external jugular vein
-supplies skin over angle of mandible and parotid gland, and both surfaces of lower part of auricle


Transverse cervical nerve

-cutaneous branch of cervical plexus
-C2, C3
-runs anteriorly, superficial to sternocleidomastoid
-supplies skin of anterior and lateral aspects of neck


Supraclavicular nerves

-cutaneous branch of the cervical plexus
-C3, C4
-arise by a common trunk, which divides into medial, intermediate, and later supraclavicular nerves
-descend across side of lower neck
-supply skin at base of neck and skin that covers upper parts of pectoral is major and deltoid muscles


What are the medial branches of dorsal rami of cervical spinal nerves?

-greater occipital nerve (C2)
-3rd occipital nerve (C3)
-from 4th, 5th, 6th, and 7th nerves in succession below


What is the platysma?

The muscle embedded in superficial fascia of neck


Origin of platysma

Deep fascia that covers upper parts of pectoralis major and deltoid muscles


Insertion of platysma

Fibers pass superficial to clavicle and run superiorly and medically over side of neck, some fibers insert into lower border of body of mandible, other fibers enter face and blend with muscles of lower lip and angle of mouth


Nerve supply of platysma

Cervical branch of facial nerve (CN VII)


Actions of platysma

-tenses skin of neck
-helps to depress mandible
-draws down lower lip and angle of mouth


External jugular vein

-begins posterior to angle of mandible by union of posterior auricular vein and posterior branch of retromandibular vein
-descends obliquely, superficial to sternocleidomastoid, toward middle of clavicle, pierces investing layer of deep cervical fascia, then drains into subclavian vein


Posterior auricular vein

Drains scalp posterior and superior to auricle


Retromandibular vein

-formed within parotid gland by union of superficial temporal and maxillary veins
-at lower end of gland it divides into anterior and posterior branches (anterior joins facial vein, posterior joins posterior auricular vein to form EJV)


Trubutaries of EJV

Transverse cervical
Supra scapular
Anterior jugular veins


Where does the anterior jugular vein begin?

In submental region by union of several small veins


Where does the anterior jugular vein descend?

Close to anterior midline, just superior to jugular (suprasternal) notch of sternum it turns laterally and passes posterior (deep) to sternocleidomastoid, then drains into external jugular vein


What are the right and left anterior jugular veins USUALLY joined by?

Usually joined across midline by jugular venous arch


Origin of sternocleidomastoid

Anterior surface of mnubrium of sternum and superior surface of medial third of clavicle (clavicular head)


Insertion of sternocleidomastoid

Two heads of origin, muscle passes superiorly, posteriorly, and laterally, then inserts into mastoid process and lateral part of superior nuchal line


Nerve supply to the sternocleidomastoid

-Accessory nerve (CN 11) for motor.
-Branches from ventral rami of C2 and C3 spinal nerves (proprioceptive)


What divides the anterolateral part of neck into anterior and posterior triangles?



Sternocleidomastoid actions

-unilateral contraction
-bilateral contraction


Unilateral contraction of the sternocleidomastoid

-lateral flexion of head and neck to sam side of contracting muscle
-rotation of head and neck to opposite side of contracting muscle


Bilateral contraction of sternocleidomastoid

-draw head forward
-flexion of head and neck against resistance (doing sit up)
-if head is fixed, it can act as an accessory muscle of inspiration


What does deep cervical fascia consist of?

Connective tissue that supports muscles, vessels, nerves, and viscera of neck