week six - musc of tongue, facial expression Flashcards
distinguish between intrinsic and extrinsic striated muscles of the tongue
intrinsic
- origin + insertion contained entirely within tongue
- func : alters tongue shape
extrinsic
- origins outside of tongue byt all insert fibres into tongue
- mainly act to change tongue position
list between the four intrinsic muscle groups of the tongue, their innervations, arterial supply and func
- sup.longitudinal group
- inf.longitudinal group
- transverse group
- vertical group
innervated by hypoglossal n.
supp by lingual a.
func: changes shape in all planes
describe the origin, insertion and action of:
intrinsic tongue musc
1. sup.longitudinal group
2. inf.longitudinal group
3. transverse group
4. vertical group
- sup.longitudinal group
origin - median fibrous septum + submuc. near epiglottis
insertion - submucosa along edge of tongue
action - shortens - inf.longitudinal group [runs length of tongue]
origin - root of tongue
insertion - submucosa at apex of tongue
action - shortens - transverse group [runs width of tongue]
origin - median fibrous septum
insertion - fibrous tx in submuc. at sides of tongue
action - narrows - vertical group
origin - submuc. on upper layer of tongue
insertion - submuc. on lower layer of tongue
action - broadens/flattens
list between the four extrinsic muscle groups of the tongue and their innervations
- genioglossus
- hyoglossus
- styloglossus [smallest ext.musc]
- palatoglossus [can be classed as ext.musc or soft palate musc]
all innervated by hypoglossal n. except palatoglossus [innervated by pharyngeal part of vagus n. + cranial part of accessory n.
describe the origin, insertion and action of:
- genioglossus
- hyoglossus
- styloglossus
- palatoglossus
- genioglossus
origin - sup.genial tubercles of mand.
insertion - ventral surface of tongue
action - protrusion + depression of tongue - hyoglossus
origin - hyoid bone
insertion - lateral border of tongue
action - depression - styloglossus
origin - styloid process
insertion -lateral border + apex + border of body + base
action - retracts + slightly elevates - palatoglossus
origin - ant.soft palate
insertion - lateral border
action - elevates + narrows post. part tongue
describe the hyoid musc., it’s two divisions
can be considered accessory to MOM [involv in speech/chewing]
both groups active in
- stabilising hyoid bone
- depressing mand.
- movement of voice box + tongue
- suprahyoid group [sup. to hyoid bone]
- form BULK of FOM
- connect hyoid bone –> skull
- elevate hyoid bone
- geniohyoid, mylohyoid,stylohyoid, diagastric - infrahyoid group [inf. to hyoid bone]
- called strap musc [due to appearance]
- anchor + depress hyoid bone
describe the origin, insertion, actions and innervation of the suprahyoid muscle group
geniohyoid
origin - inferior genial tubercles
insertion - hyoid bone
actions - elevates hyoid bone + depress mand.
innervation - c1 via hypoglossal
mylohyoid
origin -mylohyoid ridge/line
insertion - hyoid bone
actions - elevates hyoid bone _ depress mand.
innervation - trigeminal [mylohyoid branch]
stylohyoid
origin - styloid process
insertion - hyoid bone
actions - elev. hyoid bone up and back
innervation - stylohyoid branch of facial n.
diagastric
origin - ant belly = diagastric fossa // post belly =mastoid process
insertion - hyoid bone via intermed.tendon
actions = elevates hyoid bone + retrudes mand. + lifts larynx
innervation - ant belly = trigeminal [mylohyoid branch] // post belly = diagastric branch of facial n.
describe the infrahyoid muscle group [strap muscles] in order of sup–>inf [TOSS]
- thyrohyoid [thyroid cartilage –> hyoid]
- depresses hyoid + raises thyroid cartilage and larynx - omohyoid [scapular –> hyoid]
- 2 bellies
- forms triangles of neck - sternohyoid [sternum –> hyoid]
- superficial to sternothyroid musc + thyroid gland + cartilage - sternothyroid [sternum –> thyroid cartilage of larynx]
- depresses thyroid caritlage + larynx
- does NOT directly depress hyoid bone
all infrahyoid muscles depress the hyoid bone –> except sternothyroid which depresses the larynx and thyroid cartilage
list the FIVE muscles of the soft palate and their func
- levator palatini =elevates palate
- tensor palatini = tenses palate
- palatoglossus = elevates and narrows post.tongue
- palatopharyngeus = hard palate + lat. wall of pharynx
- musculus uvulvae = shortens uvulva and pulls it superiorly –> aids swallowing + closes of nasopharynx
list and describe the two cervical muscles
- sternocleidomastoid [SCM]
origin - median portion of clavicle/sternum
insertion - mastoid process
action - contraction of ONE musc = face/neck rotate // contraction of TWO musc = head bends to chest
innervated by - accessory n. - trapezius
origin - external occipital bone + spinous process
insertion - lateral 3rd of clavicle, acromian, spine of scapula
action - shoulder shrug - lifts clavicle + scapula
innervated by - accessory
list the musc of facial expression, origin, insertions
- scalp group
- orbital group
- nasal group
- oral group
- neck group
innervated by branches of facial n.
originate from BONE
insert into SKIN
briefly describe the scalp group and the two muscles included
[2 musc front and back of head joined by epicranial aponeurosis aka galea aponeurotica in middle top of head]
- frontalis [front of head]
originates from aponeurosis –> skin of eyebrow/nose - occipitalis / epicranial [back of head]
originates from occipital bone –> aponeurosis
func = wrinkles in forehead, raises eyebrows
briefly describe the orbital group and the two muscles incl
- orbicularis oculi
- orbital div [forceful closing of eyelids] [sup to palpebral]
- palpebral div [gentle closing of eyes] [sup to eyeball]
innervated by temp./zygo. branches of facial n.
- corrugator supercilli
[(deep to upper portion of obicularis occuli)]
innervated by temp.branch of facial n.
draws brows medial/inf.
briefly describe the nasal group and the three muscles incl
front sup. to inf.
all inn. by facial n.
- nasalis
- compressor naris [tranverse] - compresses nostril
- dilator naris [alar] - dilates nostril - depressor septi
- nasal septum
- constricts nostril - procerus
- nose crinkles
- skin of nose bridge –> brings skin tgt to produce transverse wrinkles
briefly describe the oral group
all inn. by facial n.
- buccinator
- compresses cheek vert./horz.
- pulls angle of mouth lat. - orbiularis oris
- closes mouth
- protrusion/pursing of lips - risorius
- produces grinning/grimacing [stretches angle of mouth lat.] - zygomaticus major
- moves mouth sup./lat. = laughing - zygomaticus minor
- assists in smiling - levator labii superioris
- elevates upper lip - levator labii superioris alaeque nasi
- elevates upper lip + dilates nostril - levator anguli oris
- elevates angle of mouth
- assists in smiling - depressor anguli oris
- depresses corner of mouth/angle of lip = sadness - depressor labii inferioris
- depresses lower lip exposes mand.incis. - mentalis
- raises and protrudes lower lip
- wrinkles chin - platysma
- wrinkles neck skin
- grimace face
