Muscles

Question 1

Splenius Capitis

Answer 1

• Originates on the inferior half of the ligamentum nuchae and spinous processes of T1-6
• Inserts on the lateral half of the mastoid process and lateral third of the nuchal line
• Unilateral action is flexion and rotation of head and neck
• Bilateral action is extension of head and neck
• Innervated by the dorsal rami of middle cervical spinal nerves

Question 2

Levator Scapulae

Answer 2

• Originates in the transverse processes of cervical vertebrae 1-4
• Inserts on the medial border of scapula at the level of and above the spine
• Action is to elevate the scapula and assist in downward roation of scapula
• Innervated by C3-C5 Dorsal scapular nerve (C5)

Question 3

Scalenus Posterior

Answer 3

• Originates on the posterior tubercle of the transverse processes of C4-6
• Inserts on the external border of rib two
• Flexes the neck laterally and elevates the second rib with forced inspiration
• Innervated by rami of C7 and C8

Question 4

Scalenus Medius

Answer 4

• Originbates in the posterior tubercles of transverse process of C2 and C7
• Inserts on the superior surface of rib one, posterior to the grove for the subclavian artery
• Flexes neck laterally and elevates rib one during forced inspiration
• Innervated by ventral rami of Cervical spinal nerves

Question 5

Scalenus Anterior

Answer 5

• Originates in trhe posterior rubercles of transverse process of C4 and C6 vertebrae
• Inserts on the superior surface of rib one anterior to the groove for subclavian artery
• Flexes the neck laterally and elevates rib one during forced inspiration
• Innervated by ventral rami of cervical spinal nerves C4-6
• Same origin as Posterior, same action as Medius and insertion except posterior

Question 6

Omohyoid

Answer 6

• Originates on the superior border o scapula passes thorugh fascial sling near proximal end of the clavicle forming an inferior belly and a superior
• Superior belly inserts on inferior border of hyoid
• Depresses retracts and steadies hyoid bone
• Innervated by C1-C3 branch of the ansa cervicalis

Question 7

What are the borders of the lateral cervical triangle?

Answer 7

Anterior border is the posterior border of the sternocleidomastoid.

The posterior border is the anterior border of the trapezius.

Inferior border is the clavicle. Roof is the skin and superficical layer of deep fascia.

Question 8

What muscles of the floor does the prevertebral fascia of the lateral cervical triangle cover?

Answer 8

Splenius Capitis

Levator Scapulae

Scalenus Posterior, medius, and anterior

Omohyoid

Question 9

What nerves/vessels run through the Lateral cervical triangle?

Answer 9

Lesser occipital (C2)

Supraclavicular (C3,C4)

CN XI

Occipital artery

Transverse cervical artery

Subclavian vein and artery

External jugular vein