Muscles of facial expression are innervated by which nerve?
By the facial nerve CN VII
What four parts does the orbicularis oculi consist of?
- palpebral part
- orbital part.
- muscle of Riolan
- lacrimal part
What is the function of the palpebral part? How does it do this?
closes the eyelid gently as in sleep and blinking to keep the cornea from drying out.
Closes the palpebral fissure in a lateral to medial direction and so assists in spreading the tears across the cornea.
The orbital part attaches to what part?
Overlies the orbital rim and attaches to the frontal bone and maxilla
What are the two functions of the orbital part?
- forcefully closes the eye as in winking and squinting in bright lights to protect the eyeball against glare and dust.
- depresses the eyebrow to reduce excessive light from entering.
Moves the eyebrows down and medially.
Where is the muscles of Riolan located?
fine group of palpebral fibers at margin of upper and lower lid
What is the function of the muscle of riolan?
help keep the lid margins up against the eyeball (whether eyelids are opened or closed) with fibers of the palpebral part of orbicullaris oculli
The orbicularis oris are arranged where?
muscle fiber circularly arranged around the mouth and insert into the mucous membrane of the lips
the orbicularis oris’s function. (5)
- closes the lips (not the same as closing the mouth)
- compresses the lips against the teeth and thereby helps keep food between the teeth during mastication
- compresses the lips and protrudes the lips during whistling, sucking, or kissing
- used to puff out your cheeks
- It is important for speech
The buccinator is what part of the mouth?
thin, flat, rectangular muscle of the cheek
What are the functions of the buccinator? (4)
- ) presses cheek against the molar teeth so that food is held between the teeth while chewing and to prevent food from being stuck in the gutter between cheek and gums
- ) keeps the cheek taut preventing it from being injured while chewing
- ) When the cheeks are filled with air, buccinator compresses the cheeks to expel the air between the lips as when blowing on a wind instrument
- ) Used when whistling or sucking by forcing the cheeks against the teeth.
the smile and frown muscles are all innervated by which nerve?
The facial nerve
The frontalis muscle is part of which face part?
scalp
What is the function of the frontallis muscle?
raises the eyebrows and wrinkles the skin of the forehead
What arteries supply blood to the scalp?
branches of external carotid artery and branches of the opthalmic artery
What are the branches of the external carotid artery?
- occipital artery
- posterior auricular artery
- superficial temporal artery
What are the branches of the opthalmic artery?
supraorbital artery and supratrochlear artery
The facial nerve exits the skull through which foramen?
Stylomastoid foramen
Where had the CN VII passes through?
It has passed through the internal auditory meatus to enter the petrous part of the temporal bone.
Where do most of the motor branches of the facial nerve pass forward?
In the parotid gland
Injury to the facial muscles will produce weakness, paralysis on which side?
The same side
Where could a virus or tumor be located to compress the facial nerve? (7)
- infection or swollen parotid gland
- tumor by the internal auditory meatus foramen inside the skull or virus or tumor by the stylomastoid foramen on the inferior surface
- mass or tumor in the posterior cranial fossa
- blunt force trauma leading to fracture of petrous part of temporal bone
- middle ear infection called otis media
- facial or surgical wounds
- lyme disease
What is it called when you rule out all of the 7 symptons/signs?
Bell’s palsy
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