Exam 3 Flashcards
frontalis
raises eyebrows
occipitalis
pulls scalp posteriorly
obicularis oculi
closes eye
obicularis oris
closes and protrudes lips
buccinator
manipulate food during chewing
expels air through lips
zygomaticus major
pulls angle of mouth superiorly
pulls angle of mouth laterally
smiling
zygomaticus minor
raises lateral portion of upper lip (smiling)
platysma
depresses lower lip
depresses mandible
tenses skin of neck
masseter
elevates mandible
temporalis
elevates and retracts mandible
digastric
depresses mandible
fixator of the hyoid bone during swallowing
myohyloid
elevates hyoid bone and floor of mouth assisting tongue to push food toward the pharynx
sternohyoid
depresses hyoid bone and larynx
sternocleidomastoid
bilateral action: flexes head (chin to chest)
unilateral action: flex and rotate the head to oppisite side
scalenes (anterior, posterior, middle)
bilateral: flexes head when 1st rib is fixed, elevates rib cage with vertebral column (when neck is fixed)
unilateral: rotate head laterally
external oblique and internal oblique
bilaterally they flex the trunk
transversus abdominus
compresses abdominal contents
rectus adbominus
flexes the trunk
pectoralis major
flexes and adducts the arms
rotates arm medially
pectoralis minor
protracts and depresses scapula
serratus anterior
protracts scapula
assists in upward rotation of scapula
diaphragm
flattens to lower floor of thoracic cavity, increasing volume
external intercostals
elevates rib cage
trapezius
extends the head
retracts scapula
depresses scapula
rotates scapula upward
deltoid
abducts the arm
secondarily flexes and extends arm
latissimus dorsi
adducts and extends the arm
rotates arm medially
what muscles comprise the rotator cuff
supraspinatus
infraspinatus
subscapularis
teres minor
supraspinatus
assists abduction of arm
holds the humerus and stabilizes the shoulder joint
infraspinatus
rotates arm laterally
stabilizes shoulder joint