muscles of facial expression Flashcards
Name the muscles of facial expression
Muscles of Eyelids
* Orbicularisoculi
* Occipitofrontalis
* Corrugatorsupercilli
* Levatorpalpebraesuperioris
Nasal Muscles
-Procerus
-Nasalis
-Depressor septi
Muscles of Lips and Cheeks
* Levator Labii superioris alaque nasi
* Levator Labii superioris
* Zygomaticus Minor
* Zygomaticus Major
* Levator anguli oris
* Depressor labii Inferioris
* Depressor anguli oris
* Risorius
* Mentalis
* Buccinator
* Orbicularis oris
Fibers of these muscles converge to angle of the mouth & interlace to form- Modiolous
- Levator anguli oris
- Zygomaticus major
- Buccinator
- Depressor anguli oris
- Risorius
ORBICULARIS OCULI
Orbital part
origin: Medial Palpebral lig ,Frontal bone and Maxilla
insertion:Fibers elliptical arranged without interruption laterally
Palpebral part
O:Medial Palpebral lig
I:Lateral Pelpebral raphe
Lacrimal Part-Lies behind the lacrimal sac
O:Crest of lacrimal bone, Lacrimal fascia
I:Lateral Pelpebral raphe
action:
* Entire Muscle:
a. Acts as sphincter- protects the eye from intense light &
from injury
b. Draws the skin of forehead, temple & cheek towards medial angle of eye- produces radiating skin folds at the lateral angle of eyes- Crow’s Feet
* Palpebral Part- Gentle closure of eyelids- blinking or sleep
* Lacrimal part- facilitates transport of lacrimal fluid
N: temporal n zygomatic br of facial. N
Paralysis of orbicularis oculi:
Ectropion- Drooping of lower eyelid
Epiphora- Spilling of tears
Corrugator Supercilli
O:Medial End of the superciliary arch of the frontal bone
I: subcutaneous tissues of the eyebrow
N: temporal br
A:Drags the eyebrow downwards and medially- Vertical wrinkles of forehead
Occipito- Frontalis
Occipital belly
O:Superior nuchal line of occipital bone and Mastoid bone
I:Epicranial aponeurosis
Frontal Belly
O:Skin & subcutaneous tissues of eyebrow & root of nose
I:Epicranial aponeurosis
N: frontalis
A:* Alternate contraction- forward and backward movement of entire scalp
-transverse wrinkles of forehead
* Frontal Belly – from above- raises eyebrow as in surprise
LEVATOR PALPEBRAE SUPERIORIS
- Origin- Lesser wing of the sphenoid bone
- Insertion – Medial Palpebral lig. and zygomatic bone
- Nerve supply: oculomotor nerve
- Elevates the upper eyelid
Levator Labii superioris alaeque nasi:
Origin: maxilla
Insertion: Ala of the nose & skin
of the upper lip
Actions: Elevates & everts upper lip, Dilates the nostril
N: upper buccal br
Levator Labii superioris
Origin: lower margin of the
orbit
Insertion: upper lip
A:Elevates & everts the upper lip Increases the naso labial furrow
N: upper buccal
Zygomaticus minor
- Origin: Zygomatic bone
- Insertion: Upper lip
N: upper buccal
Actions:
Elevates & everts the upper lip Increases the naso labial furrow
Levator Anguli oris
- Origin: Maxilla- just below infra orbital foramen
- Insertion- Angle of mouth, fibers also extend to skin of lower lip upto mid line
N: upper buccal br - Actions:
Raises the angle of the mouth
Levator anguli oris+ levator labii superioris + zygomaticus minor- Accentuates nasolabial furrow as in SADNE
Zygomaticus Major
Origin- Zygomatic bone
* Insertion- Angle of mouth
* Actions:
Draws the angle of the mouth upward & laterally – as in
laughing
N: upper buccal br
C:Spasm of this muscle in case of tetanus- risus sardonicus
Depressor Labii Inferioris
Depressor Labii Inferioris
Origin: oblique line of mandible
Insertion: Skin of the lower lip
N: marginal mandibular
Actions: draws the lower lip downward & laterally- as in irony
Depressor anguli oris
Origin: posterior part oblique line of mandible
Insertion: Angle of mouth & Skin of the upper lip
N: marginal mandibular
Actions: draws the lower lip downward & laterally- as in Sadness
Risorius
- Origin : Parotid fascia- continuation of posterior fibers of platysma
- Insertion: angle of mouth
N: marginal mandibular - Action: Retracts the angle of mouth as in grinning
- Mentalis:
- Muscle of chin
- Origin: incisive fossa of mandible
- Insertion: skin of chin
N: marginal mandibular - Action: puckers the chin
Protrudes lower lip
in drinking or in expression of disdain
Buccinator- VERY IMPORTANT!
Origin:
1. Outer surface of alveolar processes of maxilla and mandible opposite to 3rd molar teeth
2. Pterygomanibular raphe
3. Fibrous band from pterygoid hamulus to maxillary tuberosity
Insertion:
Upper or maxillary fibers – upperlip
Intermediate fibers- Chiasmatic decussation at modiolous
Upper fibers- lower lip
Lower fibers- Upper lip
mandibular fibers- lower lip
-Outer surface covered by BUCCOPHARYNGEAL fascia. separated from mandible & masseter by Buccal pad of fat
- Inner surface- covered by Mucous membrane
N: lower buccal br
Actions:
a. Flatens the cheek against gum & teeth- helps in mastication- by preventing accumulation of food in vestibule of mouth
b. Forcibly expels air b/w lips from inflated vestibule- as in blowing trumpet
Structures Piercing :
a. Parotid duct
b. Buccal branch of mandibular nerve
c. mucous glands around parotid duct
Oribicularis oris
Extrinsic part - 3 strata- Deepest , intermediate, superficial
* Intrinsic part
- Origin:
- Deepest strata: incisive fossa of maxilla and mandible – fibers pass laterally & continuous with other muscles at lateral angle of mouth.
- Intermediate strata: derived from buccinator muscle
- Superficial strata: formed by levator & depressor anguli oris
Intrinsic part- fibers extend from skin to mucous membrane of the lip
N: buccal n marginal mandibular
Actions:
* Closes the lips
* Deep strata-Compress the lips against the teeth & help in mastication
* Superficial strata- Protrudes the lips- as in pursing
* Helps in articulation of speech
* KISSING
procerus
O: fascia covering the nasal bone
I: skin between eyebrows
A: transverse wrinkles across the nose- frowning
N: upper buccal
nasalis compressor naris
O: maxilla
I: cont. with opp muscle
A:compress the nasal aperture
N: upper buccal
nasalis dilator naris
O: Maxilla
I: Alar cartilage
A: dilates the anterior nasal aperture- anger
N: upper buccal
depressor septi
O:Maxilla-incisive fossa
I: mobile part of nasal septum
A: dilates the ant. nasal aperture- anger
N: upper buccal
