Most muscles connect to and move only bones, while the facial muscles mostly connect bones to skin. These muscles pull on skin to produce a seemingly  infinite number of facial expressions and to move the lips and cheeks during speech and eating. The zygomaticus major and the orbicularis oris are two such muscles that control these functions.

During times when the mouth bites and chews food the muscles that also allow for a less forceful movement to produce speech are accomplished by the masseter and temporalis muscles which elevate the jaw bone (mandible) more forcefully during chewing and more gently during speech.

There are four extrinsic tongue muscles to allow the tongue to move in virtually any direction. The eye has six extrinsic eye muscles that allow superior, inferior, lateral, medial motion, and rotation of the eyeball.

The intrinsic eye muscles located inside the eye work to dilate the pupils and focus the lens of the eye to produce clear vision.

The middle ear has the smallest muscle of the skeleton which is the stapedius. It is about 1 millimeter (1/20th of an inch) in length. It allows the middle ear to contract which lessens the amplitude of vibrations from the eardrum to the inner ear.

The Sternocleidomastoid and the Trapezius are the two neck muscles associated to gross motor movement in the head and neck. They move the head in every direction, pulling the skull and jaw toward the shoulders, spine, and scapula. These muscles work in pairs on the left and right sides of the body to control flexion and extension of the head and neck. When they work alone it allows for the head to rotate and the neck to flex either left or right. Neck muscles contract to adjust the posture of the head throughout the course of the day and this causes these muscles to endure more use than any of the muscles in the body.

Muscles of the Tongue:

• Genioglossus (protraction)

• Styloglossus (elevation and retraction)

• Hyoglossus (depresses tongue)

• Palatoglossus (elevates tongue when swallowing)

Muscles of the Head:

• Sternocleidomastoid (nodding and turning)

• Semispinalis (extends head and supports turning)

• Splenius capitis (extend head and supports turning)

• Longissimus capitis (extends head and supports turning)

• Rectus capitis posterior major (extends head)

• Rectus capitis posterior minor (extends head)