MAJOR Skeletal Muscles of the Human Body

FRONTALIS

Raises forehead & eyebrows; wrinkles forehead (horizontally)

MASSETER

Elevates mandible

TEMPORALIS

Closes jaw elevates and retracts mandible (as in chewing)

ORBICULARIS OCULI

Shopw Blinking, squinting, and draws eyebrows inferiorly LJKLJK KLJKLJ K

ORBICULARIS ORIS

Closes lips; purses and protrudes lips; kissing & whistling muscle

BUCCINATOR

Draws corners of mouth laterally; compresses cheek when sucking/whistling; holds food between teeth when chewing

ZYGOMATICUS

Smiling muscle; raises lateral corners of mouth upward

STERNOCLEIDO- MASTOID

Flexes head; helps lift head when lying down; tilts head to side

SPLENIUS

Together: extend/hyperextend the head; Separate: Rotate and tilt head to one side

TRAPEZIUS

Elevates, retracts, depresses and rotates shoulder

LATISSIMUS DORSI

Extends & adducts arm; depresses shoulder; allows movements such as striking, hammering, swimming, rowing, pull-up

DELTOID

Abducts arm; swings arms while walking

PECTORALIS MAJOR

Flexes arm; adducts arm against resistance; pulls ribcage upward; allows movements for climbing, throwing, pushing, and forced inhaling

BICEPS BRACHII

Flexes elbow joint; supinates forearm Example: open a bottle of wine, turn the corkscrew and pull cork

TRICEPS BRACHII

Extends forearm with or without resistance; reaching

RECTUS ABDOMINUS

Flex and rotate lumbar region; stabilize pelvis during walking

EXTERNAL OBLIQUE

Together: Help rectus abdominus to flex vertebral column (bending over/back) Separate: Help to rotate trunk and lateral flexion

GLUTEUS MAXIMUS

Extends thigh; when thigh is flexed, helps us to climb stairs or run; laterally rotates and abducts thigh

RECTUS FEMORIS

Extends knee and flexes thigh at hip

GRACILIS

Adducts thigh; flexes and medially rotates thigh; flexes knee

SARTORIUS

Flexes, abducts, and laterally rotates thigh; “tailor’s muscle” = sitting cross-legged

BICEPS FEMORIS

Extends thigh and flexes knee; laterally rotates leg

GASTROCNEMIUS

Plantar flexes foot when knee is extended

TIBIALIS ANTERIOR

Dorsiflexion of foot; inverts foot

FIBULARIS LONGIS

Ghgfhgfh Sfs

Plantar flexes and everts foot; helps keep flat foot on ground