Musculoskeletal: Anatomy - Muscles of back and neck

Question 1

Attachments, innervation and actions of anterior scalenes

Answer 1

Attachments: transverse processes C3-6 to 1st rib
Innervation: cervical spine nerves (C4-6)
Actions: flexes head, elevates 1st rib

Question 2

Attachments, innervation and actions of middle scalenes

Answer 2

Attachments: transverse processes C5-7 to 1st rib (posterior to groove for subclavian)
Innervation: anterior rami of cervical spine nerves
Actions: lateral neck flexion, elevates 1st rib

Question 3

Attachments, innervation and actions of posterior scalenes

Answer 3

Attachments: transverse processes C5-7 to external border 2nd rib
Innervation: anterior rami cervical spinal nerves C7-8
Actions: lateral neck flexion, elevates 2nd rib

Question 4

Attachments, innervation and actions of sternocleidomastoid

Answer 4

Attachments: lateral surface of mastoid process and superior nuchal line; sternal head to manubrium, clavicular head to medial 1/3 of clavicle
Innervation: motor from CN XI, pain/proprioception C3/4
Actions: unilateral laterally flexes neck (to same side) and rotates face to other side; bilateral atlanto-occipital extension, neck flexion, head protrusion; elevates manubrium and clavicles to aid inspiration