Muscle Manual

Question 1

Platysma Origin

Answer 1

Skin over lower neck and upper lateral thorax

Question 2

Platysma Innervation

Answer 2

Facial nerve (CN VII)

Question 3

Platysma Action

Answer 3

Depresses and wrinkles skin of lower face and mouth; tenses skin of neck; aids in forced depression of the mandible

Question 4

Platysma Insertion

Answer 4

Mandible (inferior border), skin over lower face and angle of mouth

Question 5

Sternocleidomastoid Proximal Attachment:

Sternal Head
Clavicular Head

Answer 5

manubrium

Clavicle (medial one third)

Question 6

Sternocleidomastoid Distal Attachment

Sternal Head
Clavicular Head

Answer 6

mastoid process, occipital bone (superior nuchal line)

Question 7

Sternocleidomastoid Innervation

Sternal Head
Clavicular Head

Answer 7

Motor: Accessory nerve (CN XI)

Pain and Proprioception: Cervical plexus (C2, C3)

Question 8

Sternocleidomastoid
Action
unilateral and bilateral

Answer 8

Unilateral: Tilts head to same side, rotates head to opposite side

Bilateral: Extends head, aids in respiration when head is fixed