Human Muscles - Origins and Functions Flashcards
latissmus dorsi
o - lower 6 thoracic vertebrae
f - extends, adducts, and medially rotates the arm
trapezius
o - occipital bone, C7 and thoracic vertebrae
f - stabilizes, elevates, retracts, and rotates scapula
deltoid
o - clavicle and scapula
f - adducts arm when all fibers contract simultaneously
biceps brachii
o - scapula
f - flexes and supinates the forearm
triceps
o - scapula and humerus
f - extends the forearm
brachioradialis
o - humerus
f - flexes the forearm
pectoralis major
o - clavicle and cartilage of ribs 1-6
f - adducts and medially rotates the arm
serratus anterior
o - ribs 1-8
f - rotates scapula so that its inferior angle moves laterally and upward
rectus abdominis
o - pelvic bone
f - flexes and rotates the lumbar region of the vertebral column
external oblique
o - lower 8 ribs
f - flexes vertebral column and compresses abdominal wall
gluteus maximus
o - pelvic bones, sacrum and coccycx
f - extends the thigh
rectus femoris
o - pelvic bone
f - extends the leg and flexes the thigh at the hip
vastus lateralis
o - femur
f - extends the leg and stabilizes the knee
vastus medialis
o - femur
f - extends the leg
biceps femoris
o - femur
f - extends the thigh and flexes the leg
semitendinosus
o - femur
f - extends the thigh and flexes the leg
semimembranosus
o - femur
f - extends the thigh and flexes the leg
gastrocnemius
o - femur
f - flexes foot when leg is extended
frontalis
o - epicranial aponeurosis
f - raises eyebrows and wrinkles forehead skin horizontally
occipital belly
o - occipital and temporal bones
f - fixes aponeurosis and pulls scalp posteriorly
masseter
o - zygomatic bone
f - elevates the mandible
sternocleidomastoid
o - sternum and clavicle
f - flexes and laterally rotates the head
temporalis
o - temporal bone
f - elevates and retracts the mandible
orbicularis oculi
o - frontal and maxillary bones and ligaments around the orbit
f - closes eye (+ blinking and squinting) and pulls eyebrow inferiorly
zygomaticus
o - zygomatic bone
f - raises lateral corners of the mouth
buccinator
o - maxilla and mandible
f - closes, purses, and protrudes lips
platysma
o - fascia of the chest over pectoral and deltoid muscles
f - tenses skin of the neck, depresses mandible, and pulls lower lip down
digastric
o - mandible and temporal bone
f - depresses mandible and elevates and steadies the hyoid bone
sternothyroid
o - sternum an dclavicle
f - depresses the larynx of the hyoid bone
sternohyoid
o - sternum and clavicle
f - depresses larynx and hyoid bone if the mandible is fixed
mylohyoid
o - mandible
f - elevates hyoid bone and the floor of the mouth
flexor digitorum superficialis
o - humerus
f - flexes the hand and 2nd-5th phalanges
flexor carpi ulnaris
o - humerus
f - flexes and adducts the hand
flexor carpi radialis
o - humerus
f - flexes the hand
extensor carpis ulnaris
o - humerus and ulna
f - extends and adducts the hand
extensor digitorum
o - humerus
f - extends and adducts the hand
extensor carpi radialis longus
o - humerus
f - extends and adducts the hand
fibularis longus
o - fibula
f - plantar flexes and everts the foot
tibialis anterior
o - tibia
f - dorsiflexion and inversion of the foot
extensor digitorum longus (leg)
o - tibia and fibula
f - extends the toes
soleus
o - tibia, fibula, and interosseous membrane
f - plantar flexes the foot
gracilis
o - pelvic bone
f - adducts thigh and flexes and medially rotates the leg
gluteus medius
o - pelvic bone
f - abducts and medially rotates the thigh
tensor fasciae latae
o - pelvic bone
f - steadies leg and trunk on the thigh
sartorius
o - pelvic bone
f - flexes, abducts, and laterally rotates the leg
adductor longus
o - pelvic bone
f - adducts, flexes, and medially rotates the thigh
what muscles make up the hamstrings?
semitendinosus, semimembranosus, biceps femoris
what muscles make up the quads?
rectus femoris, vastus lateralis, vastus intermedius, vastus medialis
