muscle IOAs of head and neck

Orbicularis oculi

I- the skin surrounding the eyelids

O- the medial margin of the orbit

A- closes the eyelids in blinking and squinting

Orbicularis oris

I- soft tissues at the corner of the mouth

O-the mandible

A- closes the lips

Occipitofrontalis

O- aponeurosis extending over the top of the skull

A- wrinkles on the forehead and raises eyebrows

Sternocleidomastoid

I- Mastoid process of the temporal bone

O- manubrium other head originates on clavicle

A- flexes neck, rotating and bending the head laterally

Platysma

I- mandible and muscles of mouth, chin and jaw

O- upper thorax

A- causes skin of the neck to tense as well as depresses the mandible

Zygomaticus major

I- Orbicularis oculi muscle at the corners of the mouth

O- zygomatic bone

A-draws the angle of the mouth up to smile

Temporalis

I- superior and inferior temporal lines of the parietal bones

O-coronoid process of the mandible

A- causes mandible to raise to help produce chewing motion

Buccinator

I-Orbicularis iris and deep muscles around the mouth

O-alveolar prices of mandible and maxillary bones

A- compresses the cheek to produce a “sucking” action

Masseter

I- angle of mandible

O- zygomatic arch

A- raises mandible to produce a chewing motion