Muscles of the neck

Question 1

Sternocleidomastoid Superior Attachment-2

Answer 1

• Lateral surface of mastoid process

- Lateral half of superior nuchal line

Question 2

Sternocleidomastoid Inferior Attachment-2

Answer 2

• Sternal head: anterior surface of manubrium of sternum

- Clavicular head: superior surface of medial third of clavicle

Question 3

Sternocleidomastoid Innervation-2

Answer 3

• Spinal accessory nerve (CN XI; motor)

- C2 and C3 nerves (sensory)

Question 4

Sternocleidomastoid Action-3

Answer 4

Unilateral: -Laterally flexes neck
-Contralateral rotation

Bilateral: -Extends head