Human Anatomy: Facial Muscles Overview

Questions and Answers

What is the origin of the Obicularis Oris?

Zygomatic Arch

No bony attachment (correct)

Canine Fossa

Frontal Bone

What is the action of the Buccinator Muscle?

Pulls each labial commissure laterally and shortens the cheek both vertically and horizontally.

What does the Corrugator Supercilli muscle do?

Draws the skin of the eyebrow medially and inferiorly toward the nose, causing wrinkles.

Where does the Levator Anguli Oris Muscle insert?

Skin of the ipsilateral labial commissure. Signup and view all the answers

What is the main action of the Temporalis Muscle?

Elevates the mandible Signup and view all the answers

What does the Medial Pterygoid Muscle do?

Elevates the mandible, raising and lowering the jaw. Signup and view all the answers

What is the action of the Lateral Pterygoid Muscle?

Depression of the mandible during the opening of the jaws. Signup and view all the answers

What is one of the strongest muscles in the head and neck?

Masseter Muscle. Signup and view all the answers

What is the main action of the Mentalis Muscle?

Raising the chin and protruding the lower lip. Signup and view all the answers

What does the Platysma muscle assist with?

Raising the neck skin and grimacing. Signup and view all the answers

What is the origin of the trapezius muscle?

External surface of the occipital bone and posterior midline of the cervical and thoracic regions. Signup and view all the answers

What is the insertion of the Risorius Muscle?

Labial commissure. Signup and view all the answers

Study Notes

Obicularis Oris

Origin: No bony attachment; directly inserts into the lips.
Action: Controls mouth and lip movement, including closing, opening, pursuing lips, and kissing.

Buccinator Muscle

Origin: Alveolar processes of the maxilla and mandible, and the pterygomandibular raphe.
Insertion: Skin of the labial commissure.
Action: Pulls labial commissures laterally and shortens the cheek vertically and horizontally.

Corrugator Supercilli

Origin: Frontal bone in the supraorbital region.
Insertion: Skin of the eyebrow.
Action: Frowning (crows feet); draws eyebrow skin medially and inferiorly towards the nose, creating wrinkles.

Levator Anguli Oris Muscle

Origin: Canine fossa.
Insertion: Skin at the ipsilateral labial commissure.
Action: Raises the corner of the mouth.

Temporalis Muscle

Origin: Fossa on the temporal bone.
Insertion: Coronoid process and ramus of the mandible.
Action: Elevates the mandible, raising the lower jaw.

Medial Pterygoid Muscle

Origin: Pterygoid plate of the sphenoid bone, palatine bone process, and maxillary tuberosity.
Insertion: Medial surface of the ramus and angle of the mandible.
Action: Elevates the mandible and parallels the masseter muscle, though it is weaker.

Lateral Pterygoid Muscle

Origin: Superior head from the greater wing of the sphenoid bone; inferior head from the lateral pterygoid plate of sphenoid bone.
Insertion: Pterygoid fovea of the mandible, TMJ disc, and capsule.
Action: Depresses the mandible, facilitating jaw opening and moving the mandible forward.

Masseter Muscle

Origin: Zygomatic arch from various areas.
Insertion: External surface of the mandible.
Action: Elevates the mandible during jaw closing; one of the strongest muscles involved in mastication.

Mentalis Muscle

Action: Raises the chin and protrudes the lower lip.

Platysma

Action: Assists in raising neck skin and grimacing.

Trapezius Muscle

Origin: External surface of the occipital bone and posterior midline of the cervical and thoracic regions.
Insertion: Lateral third of the clavicle and parts of the scapula.
Action: Lifts the clavicle and scapula.

Risorius Muscle

Insertion: Labial commissure; aids in smiling and grimacing.

Description

This quiz provides an overview of key facial muscles, including their origins, insertions, and actions. Test your knowledge on the Obicularis Oris, Buccinator, Corrugator Supercilli, and other important muscles associated with facial expressions and movements.