The muscles of facial expression Flashcards
Where are the muscles of facial expression developed from?
The mesoderm of the 2nd pharyngeal arch
What are the muscles of facial expression supplied by?
The nerve of the 2nd arch - Facial nerve[motor supply]
Muscles are differentiated functionally to form…
groups around the orifices
There is … on the face
NO deep fascia
What is the function of the sphincters and dilators?
The sphincters and dilators enable us to move our skin and change our facial expression
Constrictors and sphincters diminish the volume of spaces or the area of structures, and dilators increase them
Name the muscle that is found around the scalp.
Occipito-frontalis
Name the muscles found around the nose.
• Procerus • Nasalis • Depressor septi • Levator labii superioris alaeque nasi
Name the muscles found around the eye.
- Orbicularis oculi
- Levator palpebrae superioris
- Corrugator supercilii
Name the muscles found around the auricle.
Auricularis anterior
• Auricularis superior
• Auricularis posterior
Name the muscles found around the mouth.
- Orbicularis oris
* Buccinator
Upper group muscles around the mouth :
- Risorius
- Zygomaticus major
- Zygomaticus minor
- Levator anguli oris
- Levator labii superioris
Lower group muscles around the mouth :
- Mentalis
- Depressor labii inferioris
- Depressor anguli oris
Muscles of the neck :
Platysma
What does the occipito-frontalis cover?
The occipito-frontalis covers the dome of the skull from the highest nuchal line to the eyebrow
What does the occipito-frontalis consist of?
The occipito-frontalis consists of four thin layers: two frontal and two occipital
Where does each occipital part arise?
Each occipital part (Occipitalis) arises by tendinous fibres from the lateral two-thirds of the
highest nuchal line of the occipital bone and mastoid part of the temporal bone
What is each frontal part adherent to?
Each frontal part (Frontalis) is adherent to the superficial fascia
Describe the frontal part of the occipito-frontalis.
The frontal part of the occipito-frontalis has no bony attachments of its
own, its fibres blend with procerus, corrugator supercilii and orbicularis oculi
List all the actions that the occipito-frontalis muscle performs.
- Elevates the eyebrow – surprise
- Produce transverse wrinkles in the forehead when one frowns
- Draws scalp backwards and forwards
Occipito-frontalis innervation : Occipital and frontal part
Innervation
• Occipital part = posterior auricular branch of the facial nerve
• Frontal part = temporal branch of the facial nerve
ORBITAL GROUP : What is the palpebral fissure surrounded by?
Palpebral fissure surrounded by sphincter: orbicularis oculi
ORBITAL GROUP; What do the dilator mechanisms consist of ?
Dilator mechanisms consist of levator palpebrae superioris & occipitofrontalis
The orbicularis oculi has 3 parts, namely :
Orbital, palpebral and lacrimal
Origin of the orbital part :
Frontal bone, the frontal process of the
maxilla and medial palpebral ligament
Inserts of the orbital part :
Upper orbital fibres blend with the
frontal part of occipitofrontalis and corrugator
supercilii. Inferiorly and medially, blend with
levator labii superioris alaeque nasi, levator
labii superioris and zygomaticus minor
State the action of the orbital part.
Closes the eyelids tightly and shades the eye from a bright light
Origin of the palpebral part :
Medial palpebral ligament
Inserts of the palpebral part :
Lateral palpebral raphe
State the action of the palpebral part.
Contraction of palpebral fibres closes lid gently without
burying eyelashes; blinking
Origin of the lacrimal part :
Upper part of the lacrimal crest and lacrimal bone + fascia
Inserts of the lacrimal part :
Upper + lower eye lids
State the action of the lacrimal part
Dilates lacrimal sac
What action[s] does the orbital and palpebral parts perform together?
Orbital & palpebral parts contract together to close eyelids forcibly &
eyelashes are buried & only tips are visible : “screwing up eyes” causes an
eye that is brimful of tears to spill out over the cheek
Which structures are responsible for the innervation of the orbicularis oculi?
Temporal and zygomatic branches of facial nerve
Describe the corrugator supercilii.
The corrugator supercilii is a small pyramidal muscle
Where does the corrugator supercilii arise?
The corrugator supercilii arises from medial end of superciliary arch
What does the corrugator supercilii attach to?
The corrugator supercilii attaches to the skin above the middle of the
supraorbital margin
State the action performed by the corrugator supercilii.
Wrinkles the skin of forehead vertically (frowning)
Which structures are responsible for the innervation of the corrugator supercilii?
Temporal branch of the facial nerve
Name the 4 muscles of the nasal group.
Nasalis, Procerus, Depressor septi nasi, Levator labii superioris alaeque nasi
Origin of the transverse part of the nasalis.
Maxilla & incisive fossa
Inserts of the transverse part of the nasalis.
Aponeurosis across the nose
State the action of the transverse part of the nasalis.
Compress nares[nostrils or nasal openings]
Origin of the alar part of the nasalis.
Maxilla
Inserts of the alar part of the nasalis.
Alar cartilage & posterior
part of mobile septum