The facial muscles serve multiple important functions, with their primary role being to create facial expressions for non-verbal communication. Here are the key functions and characteristics of facial muscles:
Primary Functions
Facial Expressions
The main purpose of facial muscles is to produce a wide range of facial expressions that convey emotions and non-verbal cues[1][2]. This allows for complex social communication.
Controlling Facial Orifices
Some facial muscles help open, close, and shape the eyes, nose, and mouth[2]. For example:
- The orbicularis oculi closes the eyelids
- The orbicularis oris controls lip movements
Assisting with Daily Functions
Facial muscles aid in essential activities like:
- Speaking
- Eating
- Drinking
- Chewing
They do this by controlling movements of the lips, cheeks, and jaw[2].
Characteristics
Attachment
Unlike most skeletal muscles, facial muscles typically attach to bone on one end and to skin or other muscles on the other end[1][2]. This allows them to move the skin to create expressions.
Innervation
Most facial expression muscles are innervated by the facial nerve (cranial nerve VII)[1]. The muscles of mastication are innervated by the trigeminal nerve (CN V).
Structure
Facial muscles are generally thin and flat, often interweaving with neighboring muscles[1]. This complex arrangement allows for nuanced facial movements.
In summary, while controlling skin folds and orifices are part of their function, the primary role of facial muscles is to generate the diverse facial expressions crucial for non-verbal communication and social interaction.
Citations:
[1] https://www.ncbi.nlm.nih.gov/books/NBK493209/
[2] https://my.clevelandclinic.org/health/body/21672-facial-muscles
[3] https://teachmeanatomy.info/head/muscles/facial-expression/
[4] https://www.physio-pedia.com/Facial_Muscles_-_Upper_Group
[5] https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2015.00711/full
[6] https://www.ncbi.nlm.nih.gov/books/NBK595468/
[7] https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/facial-muscles
[8] https://www.sciencedirect.com/topics/neuroscience/face-muscle