Actions of Muscles Flashcards
Occipitofrontalis
Raises eyebrows, draws scalp anteriorly
Orbicularis oculi
Closes eyelids as blinking or squinting
Orbicularis oris
Closes mouth, protrudes and purses lips
Platysma
Draws an angle of mouth downward, synergist for depression of mandible
Masseter
Elevates mandible
Temporalis
Elevates mandible
Medial pterygoid
Elevates mandible and moves it side to side
Lateral pterygoid
Depresses mandible and moves it side to side
Digastric
Depresses mandible
Sternocleidomastoid
Flexes neck, rotates head to shoulder on opposite side, lateral flexion
Trapezius
Extends neck, retracts, fixes , elevates and depresses scapula
Pectoralis minor
Draws scapular anteriorly and inferiorly, elevates ribs during deep inspiration
Internal intercostals
Depress rib cage during expiration
External intercostals
Elevate rib cage during inspiration
Pectoralis major
Flexion, adducts and medially rotates upper arm
Teres major
Extends, adducts, and medially rotates upper arm
Latissimus dorsi
Extends, adducts, and medially rotates upper arm
Deltoid
Flexes, extends, abducts, medially, and laterally rotates arm
Subscapularis
Medially rotates humerus
Infraspinatus
Laterally rotates humerus
Teres minor
Laterally rotates humerus
Supraspinatus
Initiates abduction of shoulder/humerus; stabilizes shoulder joint
Biceps brachii
Flexes and supinates forearm
Triceps brachii
Extends forearm
Brachialis
Flexes forearm
Supinator
Supinates forearm
Pronator teres
Pronates forearm
Brachioradialis
Flexes forearm at elbow
Flexor carpi radialis
Flexes and abducts hand
Palmaris longus
Weak wrist flexor
Extensor digitorum
Extends digits 2-5
Flexor digitorum superficialis
Flexes digits 2-5
External oblique
Flexes vertebral column, fixes and depresses ribs, rotates trunk, compresses anterior abdominal wall
Internal oblique
Flexes vertebral column, fixes and depresses ribs, rotates trunk, compresses anterior abdominal wall
Transversus abdominis
Compresses anterior abdominal wall
Rectus abdominis
Flexes vertebral column; increases abdominal pressure and fixes and depresses ribs
Erector spinae
Prime mover for back extension
Iliopsoas
Flexes trunk at thigh; major flexor of hip
Tensor fasciae latae
Extends knee via iliotibial tract; upright postural control
Adductor longus
Adducts, flexes and laterally rotates thigh
Gracilis
Adducts thigh and flexes leg at knee
Gluteus medius
Abducts and medially rotates thigh
Gluteus maximus
Powerfully extends and laterally rotates thigh
Sartorius
Flexes leg; flexes, abducts and laterally rotates thigh
Biceps femoris
Extends thigh, flexes leg
Semitendinosus
Extends thigh and flexes leg; medially rotates leg
Semimembranosus
Extends thigh; flexes knee; medially rotates leg
Rectus femoris
Extends leg and flexes thigh
Vastus lateralis
Extends leg
Vastus medialis
Extends leg
Vastus intermedius
Extends leg
Tibialis anterior
Dorsiflexes and inverts of foot
Extensor digitorum longus
Extends toes, dorsiflexes foot, everts foot
Flexor digitorum longus
Flexes toes, plantar flexes and inverts foot
Gastrocnemius
Flexes leg; plantar flexes foot
Soleus
Plantar flexes foot
FIbularis longus
Plantar flexes and everts foot