MUSCLES OF FACIAL EXPRESSION
MUSCLES OF FACIAL EXPRESSION
FACIAL MUSCLES
- The facial muscles are a group of striated skeletal muscles innervated by the facial nerve (cranial nerve VII) which control facial expression.
- These muscles are also called mimetic muscles.
- Develop from mesoderm.
- The facial musculature is fairly unique.
- They include the only somatic muscles in the body attached on one side to bone and the other to skin; thus facial movements are specialized for expression.
- They also act as sphincters and dilators of the orifices of the face.
- Facial muscles develop from second pharyngeal arch except levator palpebrae superioris.
- The face is also one of the few places in the body where some muscles are not attached to any bone at all (e.g., orbicularis oculi, the muscle surrounding the eyes; orbicularis oris, the muscle in the lips).
MUSCLES OF FACIAL EXPRESSION
- Muscles of facial expression are subcutaneous muscles & bring about different facial expressions.
These muscles are:
- Muscles of scalp: Occipitofrontalis
- Muscles of auricle (around ear): Auricularis anterior, superior & posterior.
- Muscles of eyelids: Orbicularis oculi, corrugator supercilli, levator palpebrae superioris.
- Muscles of nose: Procerus, compressor naris, dilator naris, depressor septi
- Muscles around mouth: Orbicularis oris, buccinator, levator labii superioris alaque nasi, zygomaticus major, levator labii superioris, levator anguli oris, depressor labii inferioris, mebtalis, risorius.
- Muscles of neck: Platysma
- These muscles bring about different facial expressions:
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MUSCLES OF FACIAL EXPRESSION |
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Smiling & laughing |
Zygomaticus major |
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Sadness |
Levator labii superioris & levator angularis |
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Grief |
Depressor anguli oris |
|
Anger |
Dilator naris & depressor septi |
|
Frowning |
Corrugator supercilii & procerus |
|
Horror, terror & fright |
Platysma |
|
Surprise |
Frontalis |
|
Doubt |
Mentalis |
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Grinning |
Risorius |
|
Contempt |
Zygomaticus minor |
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Closing the mouth |
Orbicularis oris |
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Whistling |
Buccinators & orbicularis oris |
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Winking (blinking) |
Orbicularis oculi |
FUNCTIONAL GROUP OF FACIAL MUSCLES
- Functionally, most of these muscles may be regarded primarily as regulators of three openings situated on face:
- Paplpebral fissure (eye opening)
- Nostrils
- Oral fissure (mouth opening)
|
OPENING |
SPHINCTER |
DILATORS |
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PALPEBRAL FISSURE |
Orbicularis oculi |
|
|
ORAL FISSURE |
Orbicularis oris |
All the muscles around the mouth, except the orbiculsaris oris the sphincter, & the mentalis which does not mingle with orbicularis oris.
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NOSTRILS |
Compressor naris |
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NERVE INNERVATION OF FACIAL MUSCLES:
All Facial muscles are supplied by facial nerve except levator palpaberal superioris which is supplied by occulomotor nerve by following branches :
- Temporal branch – Innervates the frontalis, orbicularis oculi and corrugator supercilii
- Zygomatic branch – Innervates the orbicularis oculi.
- Buccal branch – Innervates the orbicularis oris, buccinator and zygomaticus muscles.
- Marginal Mandibular branch – Innervates the mentalis muscle.
- Cervical branch – Innervates the platysma.
Exam Question
- Facial muscles develops from mesoderm.
- Facial muscles act as sphincter & dilator of orifice of face.
- Facial muscle develops from 2nd pharyngeal arch except levator palpebrae superioris.
- Lacrimal part of orbicularis oculi is k/as Horner’s muscle.
- Levator Palpebrae superioris dilate palpebral aperture.
- Facial muscles are supplied by Facial nerve.
- Levator palpeberae superioris, only Facial muscle not supplied my facial nerve.
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