OIAs (exam 2)

Internal oblique

O: inguinal ligament, iliac crest, and lumbodorsal fascia,

I: linea, alba, pubic crest, and lower ribs,

A: compresses abdominopelvic cavity, flexes and rotates vertebral column

Transversus abdominis

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

I: Linea alba and pubic crest

A: compresses abdominopelvic cavity

External intercostals

O: inferior border of each rib

I: superior border or rib below

A: elevates ribs

Internal intercostals

O: superior border of each rib

I: inferior border of rib above

A: depresses ribs

Diaphragm

A: elevates lower ribs, expands thoracic cavity for breathing

Sternocleidomastoid

O: 2 heads: manubrium of sternum and clavicle

I: mastoid process of temporal bone

A: flexes and rotates cervical vertebral column

Erector spinae group: spinalis, longissimus, iliocostalis groups

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

Intertransversarii

O: transverse processes of vertebrae

I: transverse processes of vertebra above

A: laterally flexes vertebral column

Interspinales

O: spinous processes of vertebra

I: spinous process of vertebra above

A: extends vertebral column

Rectus abdominis

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 ribs

I: linea alba and anterior iliac crest

A: compresses abdominopelvic cavity, flexes and rotates vertebral column

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 o mouth

Frontalis (frontal belly of occipitofrontalis muscle)

O: galea aponeurotica

I: skin and muscles of forehead

A: raises eyebrows / wrinkles skin of forehead

Occipitalis (occipital belly of occipitofrontalis muscle)

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 lips

Zygomaticus major

O: zygomatic bone

I: angle of mouth

A: raises angle of mouth

Temporalis

O: temporal fossa

I: coronoid process of mandible

A: closes jaw (elevates mandible)

Masseter

O: zygomatic arch

I: mandibular angle and ramus

A: closes (elevates) and retracts mandible

Platysma

O: skin of lower neck and upper thorax

I: lower mandible and skin of the lower face

A: tenses skin of neck, depresses mandible

Risorius

O: fascia associated with masseter

I: angle of mouth

A: draws angle of mouth to side

Superior rectus

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