Muscle Actions Flashcards
Epicranius frontalis
Raise eyebrows
Epicranius occipitalis
Pull scalp posteriorly or fix aponeurosis
Orbicularis oculi
Close eye and pull eyebrow downward
Orbicularis oris
Close and protrude lips
Masseter
Elevate mandible (close jaw)
Temporalis
Elevate mandible (close jaw)
Sternocleidomastoid
Flexion of neck or rotate head toward opposite shoulder
Digastric
Elevate hyoid bone or depress mandible (open jaw)
Mylohyoid
Elevate hyoid bone & base of tongue
Sternohyoid
Depress larynx and hyoid bone
Pectoralis major
Adduct and medially rotate arm or pull chest upward to inhale
Serratus anterior
Pull scapula anterior/inferior; raise ribs to inhale
Deltoid
Abduct arm or flexion, extension or rotation of humerus
Pectoralis minor
Move scapula anterior/inferior; raise ribs to inhale
Rectus abdominis
Flex vertebral column, depress ribs, compress abdomen causing increased abdominal pressure to exhale
External oblique
Flex vertebral column, depress ribs, constrict & compress abdomen causing increased abdominal pressure to exhale, rotate trunk to opposite side
Internal oblique
Same actions as external oblique (flex vertebral column, depress ribs, constrict & compress abdomen causing increased abdominal pressure to exhale) but in perpendicular direction and rotate trunk to same side
Transverse abdominis
Compress abdomen to exhale
Trapezius
Extend head; adduct or abduct scapula and elevate or depress scapula
Latissimus dorsi
Extend, adduct and medially rotate arm
Infraspinatus
Stabilizes the shoulder joint & laterally rotates the arm
Teres minor
Stabilizes the shoulder joint & laterally rotates the arm
Supraspinatus
Stabilizes the shoulder joint & abducts the arm
Subscapularis
Stabilizes the shoulder joint & medially rotates the arm
Levator scapulae
Elevates and adducts scapula or flexes neck
Rhomboids
Retracts scapula (squares shoulders) and fixes (stabilizes) scapula
Biceps brachii
Flex forearm (strong) & arm (weakly); supinate hand
Brachioradialis
Flex forearm
Brachialis
Flex forearm
Triceps brachii
Powerfully extend forearm
Pronator teres
Pronate & weakly flex forearm
Flexor carpi radialis
Flex and abduct hand at wrist
Palmaris longus
Flex hand at wrist
Flexor carpi ulnaris
Flex and adduct hand at wrist
Extensor carpi radialis
Extend & abduct hand at wrist
Extensor digitorum
Extends fingers and hand at wrist
Extensor carpi ulnaris
Extend and adduct hand at wrist
Iliopsoas (iliacus & posas major together)
Flex trunk or thigh at hip
Sartorius
Flex, abduct & laterally rotate thigh; flex shank
Quadriceps femoris (rectus femoris, vastus lateralis & vastus medialis)
Extends and stabilizes knee
Tensor fasciae latae
Flex, abduct, and medially rotate thigh
Adductor muscles (A. magnus, A. longus, & A. brevis)
Adduct, flex, and medially rotate thigh
Pectineus
Adduct, flex, and medially rotate thigh
Gracilis
Adduct and flex thigh
Gluteus maximus
Laterally rotate, abduct & powerfully extend thigh
Gluteus medius
Abduct and medially rotate thigh
Biceps femoris
Extend thigh, flex knee, & laterally rotate leg
Semitendinosus
Extend thigh, flex knee, & medially rotate leg
Semimembranosus
Extend thigh, flex knee, & medially rotate leg
Fibularis longus
Plantar flex & evert foot
Tibialis anterior
Dorsiflex & invert foot
Extensor digitorum longus
Extend toes and dorsiflex foot
Triceps surae (Gastrocnemius)
Plantar flex foot, may flex knee
Triceps surae (Soleus)
Plantar flex foot