Cutaneous/ Superficial Muscles of Neck

Question 1

Platysma m. - superior/ medial attachment

Answer 1

Inferior border of mandible, skin, and subcutaneous tissues of lower face

Question 2

Platysma m. - inferior/ lateral attachment

Answer 2

Fascia covering superior parts of pec major and deltoid m.

Question 3

Platysma m. - innervation

Answer 3

cervical branch of facial nerve (CN VII)

Question 4

Platysma m. - action

Answer 4

• draws corners of mouth inferiorly and widens it as in expressions of sadness, fright
• draws skin of neck superiorly when teeth are clenched

Question 5

SCM m. - superior/ medial attachment

Answer 5

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

Question 6

SCM m. - inferior/ lateral attachment

Answer 6

• Sternal head: anterior surface of manubrium

- Clavicular head: superior surface of medial third of clavicle

Question 7

SCM m. - innervation

Answer 7

• Spinal accessory nerve (CNXI, motor)

- C3,4 n. (pain and proprioception)

Question 8

SCM m. - action

Answer 8

• Unilateral: tilts head to same side (laterally flexes neck) and rotates it so face is turned superiorly towards opp side
• Bilateral: extends neck at atlanto-occipital joints; flexes cervical vertebrae while flexing inferior vertebrae so chin is thrust forward with head kept level
• with cervical vertebrae fixed, may elevate manubrium and medial ends of clavicles

Question 9

Trapezius m. - superior/ medial attachment

Answer 9

medial third of superior nuchal line, external occipital protuberance, nuchal ligament, SP C7-T12, L/S and sacral SP

Question 10

Trapezius m. - inferior/ lateral attachment

Answer 10

lateral third of clavicle, acromion, spine of scap

Question 11

Trapezius m. - innervation

Answer 11

• Spinal accessory n. (CNXI, motor)

- C3, 4 n. (pain and proprioception)