Muscular System Gross Anatomy

Zygomaticus

used in smiling

Buccinator

used to suck in your cheeks

Orbicularis Oculi

used in winking

Frontalis

used to form the horizontal frown crease on the forehead or to raise your eyebrows

Orbicularis Oris

the “kissing” muscle

Masseter

Prime mover of jaw closure

Temporalis

Synergist Muscle for jaw closure

Sternocleidmastoid

prime mover of head flexion; a two-headed muscle

Rectus Abdominus

A major spine flexor; the name means “straight muscle of the abdomen”

Pectoralis Major

Prime mover for shoulder flexion and adduction

Deltoids

prime mover for shoulder abduction

External Oblique

part of the abdominal girdle, forms the external lateral walls of the abdomen

Sternocleidomastoid

acting alone, each muscle of this pair turns the head towards the opposite shoulder

Transverse Abdominis & Internal Oblique

Besides the two abdominal muscles (pairs) names above, two muscle pairs that help form the natural girdle

External Intercostal

Deep muscles of the thorax that promote the inspiratory phase of breathing

Diaphagm

An unpaired muscle that acts with the muscles named immediately above to accomplish inspiration

Trapezius

Muscle that allows you to shrug your shoulders or extend your head

Latissimus Dorsi

Muscle that adducts should and causes extension of the shoulder joint

Deltiod

Powerful shoulder abductor that is the antagonist of the latissimus dorsi; used to raise arm overhead

Hamstrings

Muscle groups that extends thigh and flexes the knee

Quadriceps

Muscle group that extends the knee

Gluteus Medius

smaller hip muscle commonly used as an injection site

Gluteus Maximus

Used to extend the hip when climbing stairs; forms buttock

Gastrocnemius

“toe dancer’s muscle

Flexor Carpi ulnaris

wrist flexor that follows the ulna (pinky)

Extensor Digitorium

muscle that extends the fingers

Flexor digitorium superficialis

muscle that flexes the fingers

Biceps Brachii

muscle that allows you to bend (flex) the elbow

Triceps Brachii

muscle that extends the elbow