What nerve innervates the muscles of facial expression?

All muscles of facial expression are supplied by the facial nerve (CN VII), which originates from the 2nd pharyngeal arch during embryological development.

What are the main functions of the muscles of facial expression?

They primarily control orifices (like the mouth and eyes) and convey emotions through non-verbal expressions, such as smiling or frowning.

Which muscles are involved in closing the eyes?

The orbicularis oculi muscle is responsible for eye closure, with parts for tight closure, gentle closure, and aiding tear drainage.

What is the role of the buccinator muscle?

The buccinator prevents food from accumulating in the vestibule during chewing and assists in blowing actions. It is innervated by the buccal branch of the facial nerve.

What is the modiolus and why is it important?

The modiolus is a fibromuscular node near the mouth angle where multiple muscles interlace. It serves as a palpable landmark for the facial artery, and surgical injury can cause facial asymmetry.

How are the muscles of facial expression clinically tested?

Testing involves specific actions: Frontalis is tested by looking up to create forehead wrinkles, orbicularis oris by whistling, and buccinator by puffing cheeks and blowing air.

What muscles control movements around the mouth?

Key muscles include the orbicularis oris (sphincter for lip movements) and nine dilator muscles (e.g., zygomaticus major for smiling, depressor anguli oris for frowning) that converge around the mouth.

Facial Expression Muscles – Anatomy & Facial Nerve (CN VII)

❓ Frequently Asked Questions