Axial Muscles: Overview and Key Concepts

This set of flashcards covers key vocabulary and concepts related to axial muscles, including definitions of various muscle groups and their functions.

Orbicularis muscles

Circular muscles around openings, e.g., orbicularis oculi (eye) and orbicularis oris (mouth).

Masseter

A large rectangular muscle on the side of the jaw, responsible for elevating the mandible.

Origin: zygomatic arch

Insertion: lateral surface of the mandibular ramus and angle of the mandible

Temporalis

A large fan-shaped muscle on the side of the skull that elevates and retracts the mandible.

origin: floor of the temporal fossa

Insertion: coronoid process of the mandible

Buccinator

A flat muscle in the cheek wall that keeps food between teeth during chewing.

Extrinsic eye muscles

Six muscles that control eye movement, consisting of four rectus and two oblique muscles.

Sternocleidomastoid (SCM)

A large diagonal muscle running across the neck, responsible for flexing and rotating the head.

Suprahyoid muscles

Muscles located above the hyoid bone that elevate the hyoid.

Digrastic

muscle with two muscle bellies that helps to depress the mandible and elevate the hyoid bone.

Stylohyoid

Muscle that runs from the styloid process of the temporal bone to the hyoid bone, assisting in elevating the hyoid during swallowing.

Infrahyoid muscles

Muscles located below the hyoid bone that depress the hyoid.

Scalene muscles

Muscles located at the side of cervical vertebrae that elevate the first two ribs and assist in breathing.

Erector spinae

The largest intrinsic back muscle group responsible for extending the spine.

Intercostal muscles

Muscles located between the ribs that aid in breathing by elevating or depressing ribs.

Diaphragm

The main muscle of breathing that separates the thoracic and abdominal cavities.

Rectus muscles

Eye muscles that run straight from the back of the orbit to the eye, involved in eye movement.

Oblique muscles

Eye muscles that run diagonally across the eyeball, involved in eye movement.

Accessory nerve (CN XI)

The nerve that innervates the sternocleidomastoid muscle.

Facial nerve (CN VII)

The nerve that innervates most facial expression muscles.

Iliocostalis function