Posterior Neck Muscles

Question 1

Sternocleidomastoid Insertion

Answer 1

Lateral surface of mastoid process of temporal bone and lateral half of superior nuchal line

Question 2

Sternocleidomastoid sternal head origin

Answer 2

Anterior surface of manubrium of sternum

Question 3

Sternocleidomastoid clavicular head origin

Answer 3

superior surface of medial third of clavical

Question 4

Sternocleidomastoid innervation

Answer 4

Spinal accessory nerve (CN XI: motor); C2 and C3 nerves ( pain and proprioception)

Question 5

Sternocleidomastoid action

Answer 5

Unilateral: laterally flexes neck ipsilaterally, rotates the neck contralaterally
Bilateral: (1) Extends neck at atlanto-occipital joints (2) flexes cervical vertebrae (3) extends superior cervical vertebrae while flexing inferior vertebrae so chin is thrust forward (protrusion)

Question 6

Trapezius origin

Answer 6

Medial third of the superior nuchal line; external occipital protuberance; nuchal ligament; spinous processes of C7-T12

Question 7

Trapezius insertion

Answer 7

Lateral third of clavicle, acromion, and spine of scapula

Question 8

Trapezius innervation

Answer 8

Spinal Accessory nerve(CN XI; motor); C2 and C3 nerves (pain and proprioception)

Question 9

Trapezius action (superior fibers)

Answer 9

Elevates, retracts, and rotates scapula superiorly.

Descending (superior)fibers: elevate pectoral girdle, maintain level of shoulders against gravity or resistance

Question 10

Splenius Capitis origin

Answer 10

Nuchal Ligament and spinous processes of C7-T3/T4

Question 11

Splenius Capitis insertion

Answer 11

Lateral aspect of mastoid process and lateral third of superior nuchal line

Question 12

Splenius Capitis innervation

Answer 12

Posterior rami of middle cervical spinal nerves

Question 13

Splenius Capitis Action

Answer 13

Unilateral: rotates and laterally flexes head and neck ipsilaterally
bilateral: extend head and neck

Question 14

Levator Scapulae origin

Answer 14

Posterior tubercles of transverse processes of C1-C4 vertebrae

Question 15

Levator Scapulae insertion

Answer 15

Medial border of scapula superior to root of scapular spine

Question 16

Levator Scapulae innervation

Answer 16

Dorsal Scapular nerve (C5); Cervical nerves C3 and C4

Question 17

Levator Scapulae Action

Answer 17

Elevates scapula and tilts its glenoid cavity inferiorly by rotating scapula

Question 18

Anterior Scalene Origin

Answer 18

Transverse processes of C3-C6 vertebrae

Question 19

Anterior Scalene Insertion

Answer 19

1st rib

Question 20

Anterior Scalene Innervation

Answer 20

Cervical spinal nerves C4-C6

Question 21

Anterior Scalene action

Answer 21

Flexes cervical spine (anteriorly or laterally)

Question 22

Anterior Scalene Roots

Answer 22

C4-C6

Question 23

Middle Scalene Origin

Answer 23

Posterior tubercles of transverse processes of C5-C7 vertebrae

Question 24

Middle Scalene Insertion

Answer 24

Superior surface of 1st rib; posterior to groove for sub-clavian artery

Question 25

Middle Scalene Innervation

Answer 25

Anterior rami of cervical spinal nerves

Question 26

Middle Scalene Action

Answer 26

Flexes neck laterally; elevates 1st rib during forced inspiration

Question 27

Middle Scalene Roots

Answer 27

C7, C8

Question 28

Posterior Scalene Origin

Answer 28

Posterior tubercles of transverse processes of C5-C7 vertebrae

Question 29

Posterior Scalene Insertion

Answer 29

External border of 2nd rib

Question 30

Posterior Scalene Innervation

Answer 30

Anterior rami of cervical spinal nerves C7 and C8

Question 31

Posterior Scalene Action

Answer 31

Flexes neck laterally; elevates 2nd rib during forced inspiration

Question 32

Posterior Scalene Roots

Answer 32

C7, C8