axial musculature (theory) Flashcards
axial musculature function
- helps position the head and vertebral column
- moves the rib cage
4 axial muscle groups
- muscles of the head and neck
- muscles of the vertebral column
- oblique and rectus muscles (eyes)
- muscles of the pelvic floor
muscle groups of the head and neck
- facial muscles
- extra-ocular muscles
- mastication
- pharynx
- tongue
- neck (anterior)
facial muscle nerve supply
the facial nerve (CN VII)
extra-ocular nerve supply
the extra and intra ocular muscles are supplied by the occulomotor nerve (CN III)
EXCEPT
the lateral rectus (CN VI) and the superior oblique (CN IV)
CN VI
abducens nerve
CN IV
trochlear nerve
mastication nerve supply
trigeminal nerve (CN V)
facial expression muscles
- buccinator
- depressor labii inferioris
- levator labii superioris
- orbicularis oris
- levator anguli oris
- depressor anguli oris
- zygomatic major and minor
- risorius
- mentalis
frontal belly of the occipitofrontalis
helps move the eyebrows
orbicularis oculi
helps close the eye
nasalis
compresses the nose bridge
zygomaticus minor
moves lips up and back
zygomaticus major
has dimples
orbicularis oris
helps with whistling and blowing of the mouth
risorius
helps with smiling
mentalis
wrinkles the chin (pouting muscle)
epicranial aponeuroses
connects the occipitofrontalis and the posterior occipitalis
temporoparietalis
tenses the scalp and moves the ear
procerus
changes the shape of the nostrils and draws the medial eyebrow inferior (line between eyebrows)
levator labii superioris
helps lift lips
buccinator
cheek muscle
the name means “trumpet player”
the buccinator is utilized for blowing air
depressor anguli oris
helps pull the lip down
platysma
a muscle connected the mandible and covers the sternocleidomastoid muscle
this NOT a facial or mastication muscle
it tightens the skin around the neck and can depress the mandible
extra-ocular muscles
controls extrinsic eye movement
- superior and inferior obliques
- superior and inferior rectus
- lateral rectus
- medial rectus
- trochlea
trochlea
a ligamentous sling that the superior oblique passes through, this acts as a pulley
this helps the superior oblique twist the eye down and laterally to the side
superior and inferior rectus
superior = eye looks up
inferior = eye looks down
superior oblique
pulls the eye down and laterally
innervated by CN IV (trochlear nerves)
lateral rectus
innervated by the abducens nerve (CN VI)
this pulls the eye laterally
medial rectus
pulls the eye towards the medial line
eye paralysis example
if you recognize the eye is pointing to the midline and the patient can’t point their eye to the side laterally, there’s likely a problem with the lateral rectus or the abducens nerve (CN VI) that supplies it
levator palpebrae superioris
helps lift the eye lid up
mastication muscles
all mastication muscles are supplied by the trigeminal nerve (CN V)
- masseter
- temporalis
- pterygoids
masseter
elevates the mandible and closes the jaw
also helps protract and retract the mandible