Skeletal Muscles Head & Neck Practical

Question 1

Buccinator

Answer 1

compresses cheek (whistling and sucking)
holds food between teeth during chewing
draws corner of mouth laterally
well developed in nursing infants

Question 2

frontalis

Answer 2

has a fixed aponeurosis
raises the eyebrows
wrinkles forehead horizontally

Question 3

occipitalis

Answer 3

fixes aponeurosis

pulls scalp posteriorly

Question 4

zygomaticus (major and minor)

Answer 4

raises lateral corners of mouth (smiling muscle)

Question 5

obicularis oculi

Answer 5

closes eye
produces blinking and squinting
draws eyebrows inferiorly

Question 6

obicularis oris

Answer 6

closes lips
purses and protrudes lips
kissing and whistling

Question 7

masseter

Answer 7

prime mover of jaw closure
elevates mandible
mastication

Question 8

temporalis

Answer 8

closes jaw
elevates and retracts mandible
maintains position of the mandible at rest
deep anterior part may help protract mandible

Question 9

sternocleidomastoid

Answer 9

flexes and laterally rotates the head
simultaneous contraction of both muscles flexes neck, generally again resistance as when raising head when lying on back
acting alone, each muscle rotates head toward shoulder on opposite side and tilts or laterally flexes head to its own side

Question 10

Trapezius

Answer 10

stabilizes, elevates, retracts and rotates scapula
middle fibers retract (adduct) scapula
superior fibers elevate scapula (as in shrugging the shoulders) or help extend head with sacpula fixed
inferior fibers depress scapula (and shoulder)