Neck

Question 1

Platysma attachments and actions

Answer 1

Attachments:
subcutaneous tissue inferior and superior to clavicle
mandible, cheek, inferior lip, orbicularis oris

Action:
depresses mandible (against resistance)

Question 2

Sternocleidomastoid attachments and actions

Answer 2

Attachments:
mastoid process and occipital bone
manubrium and medial third of clavicle

Action:
unilateral: laterally flexes and superiorly rotates neck
bilateral: extends atlanto-occipital joints
bilateral: flexes neck
bilateral: extends superior cervical vertebrae while flexing inferior cervical vertebrae

Question 3

Suprahyoid Muscles attachments and actions

Answer 3

Proximal attachments:
digastric: base of cranium
stylohyoid: styloid process
mylohyoid: body of mandible
geniohyoid: body of mandible
Distal attachments:
hyoid bone

Action:
elevate hyoid
depress mandible (against resistance)

Question 4

Infrahyoid Muscles attachments and actions

Answer 4

Proximal attachments:
omohyoid: scapula
sternohyoid: manubrium
sternothyroid : manubrium
thyrohyoid: thyroid cartilage
Distal attachments:
hyoid bone (except sternothyroid: thyroid cartilage)

Action:
fix or depress hyoid bone (and larynx: sternothyroid)

Question 5

Scalene Muscles attachments and actions

Answer 5

Proximal attachments:
anterior: transverse processes C3-C6
middle: transverse processes C5-C7
posterior: transverse processes C5-C7
Distal attachments:
anterior and middle: 1st rib
posterior: 2nd rib

Action:
anterior: flexes head
middle and posterior: laterally flex neck and elevate 1st and 2nd ribs during forced inspiration