4.2 Muscles of the Head Flashcards
what is unique about facial expression muscles
they can insert into the skin, and/or bone
*important for non verbal communication
- innervated by cranial verve VII
what are the two groups of facial muscles
muscles of the scalp and of the face
what are the facial muscles of the scalp
- Epicranius (occipitofrontalis)
- main key
- frontal belly
- occipital belly
what is the Epicranius
aka the Occipitofrontalis
*Consists frontal and occipital bellies connected by aponeurosis. Alternate action of thse two pull scalp forward and backward
- Frontal belly
- Covers forehead and dome of skull, raises eyebrows (suprise expression)
- O: Epicranial apponeurosis
- Covers forehead and dome of skull, raises eyebrows (suprise expression)
- Occipital belly
- Overlies posterior occiput, fixes origin of frontal belly
-
what is the Corrugator supercilli
* muscle of face, helps w/ facial expression
- associated w/ orbicularis oculi, draws eyebrows in medially and inferiorly (frowning)
O: frontal bone I: eyebrow
Orbicularis oculi
* head muscle part of facial expression
- thin sphincter muscle surrounding rim of orbit
- O: frontal and amxillary bones, I: eyelid
*closes eye
Zygomaticus
- has a major and minor
- muscle apir extending disgonally from cheekbone - corner of mouth
O: zygomatic bone
I: mouth
*riases lateral corners of mouth (smiling muscle)
Risorius
- slender muscle inferior and alteral to zygomaticus
O: masster
I: mouth
- draws corner of lip lateally (tenses lip, synergist of zygomaticus)
Levator labii superioris
*leva = raise, labi = lip, superior = over)
- thin muscle between orbicularis oris and inferior eye margin
O: zygomatic bone of maxilla
I: upper lip
*opens lip, raises and furrows upper lip
Depressor labii inferioris
(depressor = depresses, infer = below)
- small muscle running from mandible to lower lip
O: mandible
I: lower lip
*draws lower lip inferiorly
Depressor anguli oris
angul = angle, or = mouth
-small muscle lateral to depressor labii inferioris
O: body of mandible
I: moth
*draws corners of mouth in laterall and down
Orbicularis oris
- complicated multilayered muscle of lips w/ many fibers that run in diff directions
O: maxilla and mandible
I: mouth
*closes lips: purses, protrudes (kissing and whistling)
Mentalis
ment = chin
- one of muscle pair forming V shaped muscle mass on chin
O: mandible
I: chin
*wrinkels chin, pouts lower lip
Buccinator
bucc = cheek
-main muscle of cheek - deep to masseter
O: maxilla and mandible
I: orbicularis oris
*compresses cheek (whisteling and sucking), holds in foo while chewing
Platysma
platy = flat
- unpaired, thin superficial neck muscle
O: chest
I: mandible and mouth
*not strictly head muscle but plays role bc tensis skin of neck (shaving), helps depress mandible by pulling lower lip back and down
what are the facial muscles of the face
- corrugator supercilli
- orbicularis oculi
- zygomaticus (major and minor)
- Risorius
- levator labii superioris
- depressor labii inferioris
- depressor anguli oris
- obicularis oris
- Mentalis
- buccinator
- Platysma
What are the muscles of mastication
- four pairs all innerated by cranial nerve V
- prime movers of jaw closure: temporalid and masseter
gridning movements: pterygids
chewing role: buccinator (keeps food in interior part of mouth
what are the muscles that promote tomgue movements
- genioglossus, hyoglossus and styloglossus
Masseter
Muscle of head: mastication
*maseter = chewer
- covers alteral aspect of mandibular ramus
O: zygomatic bone
I: mandible
*prime mover of jaw closure - elevates the mandible
temporalid
msucles of head: mastication
- fan shaped muscle, covers part of temportal, frontal and parietal bones
O: temportal
I: mandible
*closes jaw: elevates and retracts mandible
Medial pterygoid
pterygid: winglike
*muscles of head: mastication
- deep, two headed muscle runs along interal surface of mandible
O: sphenoid bone, maxilla
I: mandible
* Acts w/ lateral pterygoid to protract and promote side to side movements (grinding)
Lateral pterygoid
- muscle of head: mastication
- deep two headed muscle, lies superiorly to medial pterygoid
O: sphenoid bone
I: mandible
*forward sliding and side to side grinding movements of lower teeth
Genioglossus
- geni = chin, glossus = tounge
- fan shaped, forms bulk of inferior part of tongue
- attachemnt to mandible prevents tounge from falling back
O: mandible
i: hyphoid bone
*protract tongue: depress or act in synergy with other extrinsic muscles
Hyoglossus
flat bone (hyp = pertaining to hyoid bone
o: hyoid bone
*depresses tongue, draws it to sides inferiorly
Styloglossus
* stylo= pertinaing to styloid process
- slender muscles running superiorly to and at right angles to hyoglossus
O: temportal bone
*retracts and elevates tongue
what are the muscles of the Anterior Neck and Throat involved in swallowing?
- Sternocleidomastoid muslce: divides neck into two triangles (anterior and posterior)
*anterior divided based on lcoation to hyoid (supra or infra)
- tongue and buccinator
- epiglottis: closes over larynx while muscles in walls of pharync propel food froward to stomach
What are the suprahyoid muscles?
- Digastric, stylohyoid, mylohyoid, geniohyoid
Digastric
*di = two, gaster = belly
- consists of two bellies united by intermediate tendon, forms V shape under chin
- O: mandible and temporal bone
I: hyoid bone
*open mouth and depress mandible
What are the infrahyoid muscles
Sternohyoid, sternothyroid, omohyoid, thyrohyoid
sternohyoid
*muscle of eck and throat: swallowing
- most medial muscle of neck, superficial except inferiorly where covered by sternocleidomastoid
O: Manubrium and clavicle
I hyloid
*depresses larynx and hyoid bone if mandible is fixed
Omohyoid
omo = shoulder
- straplike muscle with two bellies united by intermediate tendom
*lateral to sternohyoid
O: scapula
I: hyoid bone
*depresses and retracts hyoid bone
Thyrohyoid
- appears as superior continuation of sternothyroid muslce
O: thyroid carilage
I: hyoid bone
*depresses hyoid bone or elevates larynx if hyoid is fixed
Pharyngeal Constrictor msucles
- Superior, middle, and inferior pharyngeal constrictor muscles
- three rapird muscles whos fibers run circularly in pharynx wall: superior muscle in innermost and inferior one is outermost
O: mandible, hyoid and laryngeal
I: pharynx
*constrict pharynx during swallowing
Overall roll of suprahyoid muscles
- form floor of oral cavity
anchor tongue
elevate hyoid bone
move larynx during swallowing
overall roll of infrahyoid muscles
depress hyoid bone and larynx during swallowing
