Muscles in facial expression
Muscles of Facial Expression
Facial expression muscles are specialized muscles in the face that enable non-verbal communication and the conveyance of emotions.
They originate from the surface of the skull and insert into the connective tissue and dermis of the skin, allowing the skin to move as the muscles contract.
Key Muscles
Orbicularis Oris
A round muscle that allows movement of the lips.
Key in actions such as smiling and puckering.
Orbicularis Oculi
Another round muscle that helps in closing the eyes.
Important for protecting the eyes and for blinking.
Occipitofrontalis Muscle
Composed of two parts: frontal belly and occipital belly.
Frontal belly moves scalp and raises eyebrows; occipital belly moves the scalp.
Connected by the epicranial aponeurosis (galea aponeurosis).
Buccinator Muscle
A significant muscle that squashes cheeks together.
Functions in actions like whistling, blowing, and chewing.
Corrugator Supercilii
A smaller muscle responsible for moving the eyebrows.
Can be felt upon raising or lowering eyebrows, contributing to expressions of surprise or frowning.
Additional Muscles and Actions
Facial expression muscles are involved in various movements and emotional displays:
Raising and lowering eyebrows:
Occipitofrontalis and corrugator supercilii are the prime movers.
Flaring nostrils:
Controlled by the nasalis muscle.
Movements around the mouth:
Includes actions like raising and lowering the lip facilitated by muscles like levator labii superioris and depressor labii inferioris.
Table of Muscles of Facial Expression
Overview of facial expression muscles includes:
Muscle name
Primary action (e.g., raising eyebrows)
Target area (e.g., upper lip)
Origin and insertion points
Terms to Know
Dermis:
The inner layer of skin containing blood vessels, nerves, and glands that contributes to skin structure and temperature regulation.
Risorius:
A muscle aiding in the lateral movement of the cheeks, important for sucking motions.