Head, Neck, Thorax and Abdominal Muscles OIA

table 10.1-10.3

Buccinator

O: alveolar process of mandible and maxilla

I: angle of mouth

A: compresses cheek against molars

Depressor anguli oris

O: anteriolateral surface of mandibular body I: angle of mouth
A: depresses angle of mouth

frontalis

O: galea aponeurotica

I: skin and muscles of forehead

A: raises eyebrows / wrinkles skin of forehead

Occipitalis

O: superior nuchal line of occipital bone

I: galea aponeurotica

A: tenses scalp, moves outer ear

Orbicularis oculi

O: medial margin of bony orbit

I: eyelids

A: closes eyelids

orbicularis oris

O: maxilla and mandible

I: skin surrounding mouth

A: closes and purses mouth

Zygomaticus Major

O: zygomatic bone
I: angle of mouth
A: elevates corner of mouth

Temporalis

O: temporal bone (temporal fossa)
I: coronoid process of mandible
A: elevates mandible (closes jaw)

Masseter

O: zygomatic arch and maxilla
I: angle and ramus of mandible
A: closes (elevates) and retracts mandible

Platysma

O: skin of lower neck and upper thorax

I: lower mandible and skin of lower face

A: Tenses skin of neck, depresses mandible

risorius

O: fascia over masseter
I: skin at the angle of the mouth
A: draws corner of the mouth laterally.

superior rectus

O:

I:

A: elevates eye

Inferior rectus

A: depresses eye

lateral rectus

A: moves eye laterally

medial rectus

A: moves eye medially

inferior oblique

A: elevates eye and moves eye laterally

superior oblique

A: depresses eye and moves eye laterally

Sternocleidomastoid

O: 2 heads: manubrium and sternum and clavicle

I: mastoid process of temporal bone

A: flexes and rotates cervical vertebral column

erector spinae group: spinalis group, longissimus group, iliocostalis group

O: *

I: *

A: extends and laterally flexes vertebral column, head, and neck

intertransversarii

O: transverse process of vertebrae

I: transverse process of vertebrae above

A: laterally flexes vertebral column

Interspinales

O: Spinous processes of vertebrae

I: spinous process of vertebrae above

A: extends vertebral column

Rectus Abdominus

O: pubic crest

I: xiphoid process and costal cartilages of ribs 5-7

A: compresses abdominopelvic cavity and flexes vertebral column

External Oblique

O: lower 8 ribs

I: linea alba and anterior iliac crest

A: compresses abdominopelvic cavity, flexes and rotates vertebral column

Internal Oblique

O: inquinal ligament, iliac crest, and lumbodorsal fascia

I: linea alba, pubic crest, and lower ribs

A: compresses abdominopelvic cavity, flexes and rotates vertebral column

Transverse abdominis

O: thoracolumbar facia, iliac crest, and cartilages of lower ribs

I: linea alba and pubic crest

A: compressess abdominopelvic cavity

External Intercostals

O: inferior border of each rib

I: superior border of rib BELOW

A: elevates rib

Internal Intercostals

O: superior border of each rib

I: Inferior border of rib Above

A: depresses ribs

Diaphragm

O: *

I: *

A: elevates lower ribs, expands thoracic cavity for breathing