O. I. A. Flashcards
O: Epicranial Aponeurosis
I: Skin over supraorbital margin (eyebrow skin)
A: Moves scalp, eyebrows; wrinkles skin of forehead
Frontal Belly
O: Medial wall of margin of orbit
I: Skin surrounding eyelids
A: Closes eye: produces winking, blinking, & squinting (“blink muscle”)
Orbicularis Oculi
O: Zygomatic Bone
I: Skin at superolateral edge of mouth
A: Elevates corner of the mouth (“Smile” muscle)
Zygomaticus Major
O: body of mandible
I: skin at inferior corner (angle) of mouth
A: draws corners of mouth inferiorly & laterally (frown muscle)
Depressor Anguli Oris
O: zygomatic arch
I: coronoid process, lateral surface, and angle of mandible
A: elevates and protracts mandible; prime mover of jaw closure
Masseter
O: manubrium and sternal end of clavicle
I: mastoid process
A: UNI: lateral flexion, rotation of head to opposite side
BI: flexes neck (move head back)
Sternocleidomastoid
O: Ligamentum nuchae & spinous process of c7-t6
I: Occipital bone and mastoid process of temporal bone
A: UNI: turns head to same side
BI: extends head/neck
Splenius capitis and cervicis
A: flattening of diaphragm (moves inferiorly, down) & expansion of thoracic cavity
Diaphragm
O: External and inferior borders of the inferior 8 ribs
I: Linea alba by a broad aponeurosis some to iliac crest
A: UNI: laterial flexion of vertebral column, rotation of vertebral column to the opposite side
BI: flexes vertebral column and compresses abdominal wall; used in forced exhalation
External oblique
O: Superior surface of pubis near symphysis
I: Xiphoid process of sternum; inferior surfaces of ribs 5-7
A: flexes vertebral column; compresses abdominal wall, used in forced exhalation
Rectus abdominals
O: occipital bone (superior nuchal line); ligamentum nuchae; spinous processes of C7-T12
I: clavicle; acromion process and spine of scapula
A: Superior fibers: elevate and superiorly rotate scapula
Middle fibers: retract scapula
Inferior fibers: depress scapula
Trapezius
O: Spinous processes of T7-T12; ribs 8-12; iliac crest; thoracolumbar fascia
I: Intertubercular groove of humerus
A: Agonist of arm extension; also adducts and medially rotates arm (swimmers muscle)
Latissimus dorsi
O: Medial clavicle; costal cartilages of ribs 2-6; body of sternum
I: Lateral part of intertuercular groove of humerus
A: flexion
Horizontal addiction of arms
Adduction
Medial rotation
Pectoralis major
O: Acromial end of clavicle; acromion and spine of scapula
I: Deltoid tuberosity of humerus
A: Anterior fibers: Flex and medially rotate arm
Middle fibers: Agonist of arm abduction
Posterior fibers: extend and laterally rotate arm
Deltoid
O: Long head: supraglenoid tubercle of scapula
Short head: coracoid process of scapula
I: Radial tuberosityy and bicipital aponeurosis
A: Flexes forearm, powerful supinator of forearm
Long head flexes arm
Biceps brachii
