Muscles of Head and Neck

Question 1

Semispinalis Capitis

Answer 1

Origin: Articular process of inferior cervical & transverse process of superior thoracic vertebrae.
Insertion: Occipital Bone
Action: Bilateral extend head, unilateral laterially flexes neck to same side.
Innervation: Spinal Nerves

Question 2

Sternocleidomastoid

Answer 2

Origin: Sternal end of clavicle and manubrium
Insertion: Mastoid region of skull
Action: Bilateral: Neck Flexion. Unilateral, turns face to opposite side.
Innervation: Accessory nerve (CN XI)

Question 3

Splenius Capitis

Answer 3

Origin: Spinous process/ligament of inferior cervical vertebrae
Insertion: Mastoid process, occipital bone of skull
Action: Bilateral extend head. Unilateral laterally flexes neck to same side.
Innervation: Cervical spinal nerves.

Question 4

Longissimus Cervicis

Answer 4

Origin: Transverse Processes of superior thoracic vertebrae
Insertion: Transverse process of middle and superior cervical vertebrae
Action: Bilateral extend head, Unilateral laterally flexes neck to same side
Innervation: Cervical and thoracic spinal nerves

Question 5

Longissimus Thoracis

Answer 5

Origin: Transverse process of all thoracic and lumbar vertebrae
Insertion: Transverse process of all thoracic vertebrae
Action: Bilateral extension of spine. Unilaterally, lateral flexion of spine.
Innervation: Thoracic and lumbar spinal nerves.

Question 6

Thyrohyoid

Answer 6

Origin: Thyroid cartilage of larynx
Insertion: Hyoid bone
Action: Elevates thyroid, depresses hyoid
Innervation: Hypoglossal nerve

Question 7

Scalenes (anterior, middle, posterior)

Answer 7

Origin: Transverse processes of C2-C4
Insertion: First and second ribs
Action: Elevates ribs 1 & 2
Innervation: Cervical spinal nerves