Muscles to know Flashcards
Occipital frontalis- a
action: raises eyebrow, fixes aponeurosis, pulls scalp posteriorly
zygomaticus- all
origin: zygomatic bone
insertion: skin and mouth at corner of mouth
action: raises lateral comers of mouth upward
orbicularis oris-a
closes lips; purses and protrudes (kissing and whistling muscle)
mentalis-a
protrudes lower lip; wrinkles chin
platysma-a
tenses skin of neck
masseter-all
origin: zygomatic arch and zygomatic bone
insertion: angle and ramus of mandible
action: prime mover of jaw closure
temporalis- all
origin: temporalis fossa
insertion: coronoid process
action: closes jaw; elevates and retracts mandible
sternocleidomastoid-all
origin: manubrium of sternum and medial portion of clavicle
insertion: mastoid process of temporal bone and occipital bone
action: flexion of the neck; laterally rotates the head
external intercostals- all
origin: inferior border of rib cage
insertion: superior border of rib below
action: pulls rib toward one another to elevate rip cage
internal intercostals- all
origin: superior border of rib below
insertion: inferior border of rib above
action: draw ribs together to depress rib cage
diaphragm-a
action: prime mover of inspiration flattens on contraction
external oblique- a
action: flexes vertebral column; compresses abdominal wall; aids. in trunk rotation and lateral flexion
internal oblique-a
action: flexes vertebral column; compresses abdominal wall; aids. in trunk rotation and lateral flexion
transverse abdominis- a
action: compresses abdominal contents
rectus abdominis- a
action: flexes vertebral column
pectoralis major- all
origin: clavicle, sternum, cartilage of ribs 1-6
insertion: intertubercular sulcus of humerus
action: prime mover of arm flexion; adducts, medially rotates arm
Serratus anterior- a
action: prime mover to protract and hold scapula against chest wall; rotates scapula
trapezius- a
action: raises rotates, and adducts scapula and stabilizes it
levitator scapula- all
origin: transverse processes (of C1-C4)
insertion: medial border of scapula (superior to spine)
action: elevates and abducts scapula
rhomboids- all
origin: spinous process (of C7-T5)
insertion: medial border of scapula
action: stabilizes scapula
pectoralis major- all
origin: clavicle, sternum, cartilage of ribs 1-6
insertion: intertubercular sulcus of humerus
action: prime mover of arm flexion; adducts and medially rotates arm
deltoid- all
origin: lateral 1/3 of clavicle; acromion and spine of scapula
insertion: deltoid tuberosity of humerus
action: prime mover of arm abduction
latissimus dorsi- a & i
insertion: intertubercular sulcus of humerus
action: prime mover of arm extension; adducts and medially rotates arm
teres major-all
origin: posterior surface at inferior angle of scapula
insertion: intertubercular sulcus of humerus
action: extends, medially rotates, and adducts arm
subscapularis- all
origin: subscapular fossa of scapula
insertion: lesser tubercular of humerus
action: medially rotates arm
supraspinous- all
origin: supraspinous fossa of scapula
insertion: greater tubercle of humerus
action: initiates abduction of the arm
infraspinous- all
origin: infraspinous fossa of scapula
insertion: greater tubercle of humerus
action: lateral rotation of arm
teres minor- all
origin: lateral border of dorsal scapular surface
insertion: greater tubercle of humerus
action: lateral rotation of arm
triceps brachii- a & i
insertion: olecranon of ulna
action: powerful forearm extensor
bicep brachii- a & i
insertion: radial tuberosity
action: flexes and supinates forearm
Flexors of the forearm/wrist- o & i
origin: most on medial epicondyle of humerus
action: flexes forearm
Extensors of the forearm/wrist- o & a
origin: most on lateral epicondyle of humerus
action: extends forearm
Iliopsoas→ iliacus and psoas major- a
action: flex trunk at hip joint, flex thigh; lateral flexion of vertebral column
Tensor fasciae latae- a
action: steadies trunk
sartorius- all
origin: ASIS
insertion: medial tibia
action: flexes, abducts, and laterally rotates thigh; flexes leg
Quadriceps femoris→ rectus femoris, vastus lateralis, vastus medialis, vastus intermedius- all
origin: rectus femoris on ASIS; the rest on proximal femur
insertion: tibial tuberosity and patella
action: extends leg; rectus femoris flexes thigh*
gracilis- a
action: adducts thigh; flexes and medially rotates leg
adductors of thigh- a
action: adduct and medially rotate and flex thigh
Gluteus maximus- all
origin: ilium, sacrum, coccyx
insertion: gluteal tuberosity of femur
action: powerful thigh extensor
Gluteus medius- all
origin: ilium
insertion: greater trochanter of femur
action: abducts and medially rotates thigh
Gluteus minimus- all
origin: ilium
insertion: greater trochanter of femur
action: abducts and medially rotates thigh
Hamstrings→ biceps femoris, semitendinosus, semimembranosus- o & a
origin: ischial tuberosity
action: extends thigh; flexes leg
tibialis anterior- a
action: prime mover of dorsiflexion
gastrocnemius- a
action: plantar flexes foot
soleus- a
action: plantar flexion
