Lab 7 OIA

Orbicularis oculi

Origin : frontal & maxillary

Insertion: skin of eyelid

Action: closes + blinks eyes

Zygomaticus

Origin: zygomatic bone

Insertion: skin at corner of mouth

Action: smiling

Orbicularis oris

Origin: maxilla & mandible

Insertion: Skin of mouth

Action: purse lips

Buccinator

Origin: Maxilla & Mandible

Insertion: orbicularis oris

Action: suck in cheek

mentalis

Origin: mandible

Insertion: skin of chin

Action: moves chin

masseter

Origin: zygomatic & maxilla

Insertion: mandible

Action: chewing

digastric

Origin: mandible

Insertion: loop on hyoid

Action: opens mouth

sternocleidomastoid

Origin: sternum & clavicle

Insertion: mastoid of temporal bone

Action: flexes head, yes & no rotating movement

temporalis

Origin: n/a

Insertion: n/a

Action: chewing

deltoid

Origin: clavicle & scapula

Insertion: humerus

Action: arm/shoulder abduction

pectoralis major

Origin: clavicle & sternum

Insertion: humerus

Action: arm/shoulder flexion

serratus anterior

Origin: Ribs

Insertion: scapula

Action: moves + holds scapula

external intercostal

Origin: Rib (above)

Insertion: Rib (below)

Action: breathing in

Fiber direction:

• Run downward + forward (like “hands in pockets” direction)

internal intercostal

Origin: Rib (below)

Insertion: Rib (above)

Action: breathing out

Fiber direction:

• Run downward + backward (opposite of external)

Diaphragm

Origin: ribs & sternum

Insertion: central tendon

Action: 75% work of breathing

External oblique

Origin: ribs

Insertion: Linea alba

Action: compress abdomen

internal oblique

Origin: os coxa

Insertion: linea alba

Action: compress abdomen

io

rectus abdominus

Origin: os coxa

Insertion: sternum

Action: flex spine, bend over

transverse abdominus

Origin: os coxa

Insertion: linea alba

Action: compress abdomen

ta

trapezius

Origin: vertebrae

Insertion: scapula

Action: moves and stabilizes scapula

Latissimus dorsi

Origin: vertebrae

Insertion: humerus

Action: arm adduction

Rhomboid major

Origin: vertebrae

Insertion: scapula

Action: stabilizes scapula

rhomboid minor

Origin: vertebrae

Insertion: scapula

Action: stabilizes scapula

rmi

levator scapulae

Origin: cervical vertebrae

Insertion: scapula

Action: elevate scapula

teres major

Origin: scapula

Insertion: shaft of humerus

Action: arm adduction

tm

teres minor

Origin: scapula

Insertion: head of humerus

Action: rotates arm/shoulder

supraspinatus

Origin: scapula

Insertion: head of humerus

Action: rotates arm/shoulders

s

infraspinatus

Origin: scapula

Insertion: head of humerus

Action: rotate arm/shoulder

is