Muscles & Actions Flashcards
Frontalis
Elevates eyebrows; wrinkles skin of forehead
Orbicularis oculi
Closes eyes; assists in facial expression
Orbicularis oris
Closes lips, purses and protrudes lips (kissing muscle)
Styloglossus
Draws tongue superiorly and posteriorly
Stylohyoid
Elevates and retracts hyoid bone
Massester
Elevates mandible (during chewing)
Platysma
Draws lower lip and angle of mouth downward
Sternocleidomastoid
Flexes neck if both sides contract (bilateral action); laterally flexes neck and rotates head to opposite side if one one side contracts (unilateral)
Sternothyroid
Depresses larynx; aids in singing low notes
Quadratus lumborum
Extends lumbar spine if both sides contract; ipsilateral flexion if only one side contracts; aids respiration
Erector spinae
Extend and laterally flex vertebral column; 3 parts (iliocostalis, longissimus, spinalis)
Diaphragm
Contraction expands thoracic cavity and compresses abdominopelvic cavity
External intercostal
Elevate and protract ribs, expanding the thoracic cavity
Internal intercostal
Depress and retract ribs, compressing the thoracic cavity
Rectus abdominis
“6 pack”
Flexes lumbar vertebral column; increases abdominal pressure
Transverse abdominal
Compresses abdominal contents if both sides contract
Internal abdominal oblique
Flexes vertebral column and increases abdominal pressure if both sides contract; ipsilateral rotation at waist if only one side contracts
External abdominal oblique
Flexes vertebral column and increases abdominal pressure if both sides contract; contralateral rotation at waist if only one side contracts
Lavator ani
Forms floor of pelvis, supports pelvic viscera
Trapezius
Fixes scapula and shoulder during arm movements; retracts (adducts) scapula; specific fibers aid in lateral rotation, elevation & depression
Rhomboideus major
Deep to trapezius; fixes scapula during arm movements; retracts (adducts) scapula
Serratus anterior
Protracts (abducts) scapula; prime mover in all forward-reaching and pushing actions
Pectoralis major
Flexes shoulder; adducts and medially rotates arm; horizontal flexion of arm
Deltoid
Whole muscle abducts arm; specific fibers aid in rotation of the arm and flexion, extension, horizontal extension of the shoulder
Latissimus dorsi
Extends shoulder; adducts and medially rotates arm
Supraspinatus
Abducts arm
Infraspinatus
Laterally rotates arm
Teres minor
Laterally rotates and adducts arm
Subscapularis
Medially rotates arm
Biceps brachii
Flexes shoulder and elbow; supinates forearm
Brachialis
Prime mover in elbow flexion
Brachioradialis
Flexes elbow
Pronator quadratus
Prime mover in forearm pronation
Supinator
Supinates forearm
Flexor carpi radialis
Flexes wrists; radial flexion of wrists
Flexor carpi ulnaris
Flexes wrists; ulnar flexion of wrists
Triceps brachii
Extends elbow; extends shoulder and adducts arm
Extensor capri radialis longus
Flexes wrists; radial flexion of wrist
Extensor capri ulnaris
Extends wrist; ulnar flexion of wrist
Extensor digitorum
Extends wrist and fingers
Iliacus
Flexes thigh or trunk at hip; balances trunk when sitting
Psoas major
Flexes thigh or trunk at hip; balances trunk when sitting
Iliopsoas
These two muscles joint to insert at the lesser trochanter and shaft of the femur via a common tendon
Gluteus maximus
Extends and laterally rotates hip
Adductor longus
Adducts and flexes hip
Adductor magnus
Adducts and extends hip
Gracilis
Adducts and flexes hip; flexes knee
Rectus femoris
Flexes hip; extends knee
Vastus laretalis
Extends knee
Vastus medialis
Extends knee
Vastus intermedius
Extends knee
Sartorius
Abducts and laterally rotates hip; flexes knee and medially rotates lower leg to allow cross-legged position
Biceps femoris
Extends hip; flexes knee; lateral rotation of lower leg
Semitendinosus
Extends hip; flexes knee; medial rotation of lower leg
Semimembranosus
Extends hip; flexes knee; medial rotation of lower leg
Tibialis anterior
Dorsiflexes ankle; inverts foot
Extensor hallucis longus
Extends great toe; dorsiflexes foot
Gastrocnemius
Plantar flexes ankle; flexes knee
Soleus
Plantar flexes ankle
Tibialis posterior
Plantar flexes and inverts foot
Popliteus
Medial rotation of lower leg; unlocks knee to allow flexion
Fibularis brevis
Everts foot
Fibularis longus
Plantar flexes and everts foot