FACIAL MUSCLES
have the following features:
- They develop from the mesoderm of the 2nd pharyngeal arch, so they are supplied by the facial nerve.
- They arise from bones or subcutaneous tissue of the face and inserted into the skin.
- They are responsible for facial expressions. They also serve as sphincters and dilators around openings in the face (eye, nose, and mouth).
- They are divided into functional groups (orbital, nasal, and oral groups), in addition to other muscles controlling the auricle of the ear. From all these muscles: orbicularis oculi, orbicularis oris, and buccinator muscles will be discussed in details.
- N.B: Occipito-frontalis (in the scalp) and platysma (in the neck) have the same features of muscles of the face.
* Only in the head under the skin the facial n. is found (not sensory nerves)
Orbital group: flat & circular
1. Orbicularis Oculi ( has 3 parts)
- ⓐ Orbital (outer) part
- ⓑ Palpebral (inner) part.
- ⓒ Lacrimal (deep part.)
O: Nasal part of frontal bone, frontal process of maxilla, medial palpebral ligament.
I: skin of orbital region, lateral palpebral raphe sup. & inf. tarsal plates. ( = meeting of 2 muscles)
N: temporal & zygomatic branches of facial n.
F: Orbital part - closes eyelid tightly Palpebral pt - " " gently lacrimal pt.- compresses lacrimal sac.
B.S: Ophthalmic artery
2 Corrugator supercilli m. : (eyebrows)
O: medial end of superciliary arches
I: skin of the medial half of the eyebrow
N: temporal branches of VII CN.
F: Creates vertical wrinkles above the nose
B.S: Ophthalmic art. (branch of internal carotid art.)