Ch. 11 Muscle I.D. for Dr. Jensen's Hotlist

flexion

a movement that decreases the angle between two body parts

extension

a movement that increases the angle between two body parts

abduction

a movement away from the midline (just as abducting someone is to "take them away")

adduction

a movement towards the midline

masseter

elevates mandible, on cheek

buccinator

cheek muscle important in chewing (and playing the trumpet! Latin meaning = "trumpeter")

orbicularis oculi

closes eye

orbicularis oris

compresses lips

sternocleidomastoid

flexes neck, helps rotate head

platysma

broad muscle of the neck and upper chest; depresses/wrinkles skin of neck and lower face, depresses jaw (as in horror or surprise)

pectoralis major

flexes, adducts arm, on chest

intercostal muscles

muscles between the ribs that expand and decrease the size of the chest cavity to facilitate breathing

triceps brachii

extends forearm; location = posterior humerus

biceps brachii

flexes forearm; location = anterior humerus (Remember, biceps always flex!)

extensor carpi ulnaris

extends hand at the wrist, pinky side (remember RT UP!), posterior forearm

flexor carpi radialis

flexes hand at the wrist, thumb side (remember RT UP!), anterior forearm

sartorius

flexes leg and thigh, cross leg (the "tailor" sits cross-legged)

quadriceps group: rectus femoris, vastus lateralis, vastus medialis, vastus intermedius

4 quadriceps muscles (anterior side) that extend the leg: one is "straight" above the femur, one is lateral, one is medial, and one is in the middle.

hamstring group: biceps femoris, semitendinosus, semimembranosus

3 hamstring muscles (posterior side) that flex the leg (remember, biceps always flex!)

gluteal group: gluteus maximus, gluteus minimus

extends thigh, buttock

tibialis anterior

muscle on shin that dorsiflexes (flexion at the ankle so that the foot points more superiorly; angle decreased)

gastrocnemius

muscle on posterior of lower leg that plantarflexes (extension at the ankle so that the foot points inferiorly as if "stepping on the gas"; angle increased)

rectus abdominis

flexes vertebral column (sit-up muscles aka "six pack abs")

external oblique

flexes vertebral column and rotates trunk

trapezius

upper part extends head, elevates scapula;
lower part depresses scapula, on upper back

deltoid

abducts arm, on shoulder ("shoulder pad")

latissimus dorsi

extends, adducts arm, located on back (in Latin, "broadest muscle of the back")

diaphragm

major muscle of respiration located between the thoracic and the abdominal cavities