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Muscular System – Axial Muscles MUSCLES OF THE HEAD AND NECK MUSCLES OF FACIAL EXPRESSION
Occipitofrontalis – ‘surprise’ - Location – forehead - Action – elevate eyebrows
Orbicularis oculii – ‘wink’
- Location – around eyes - Action – close eye(s) in wink
Orbicularis oris – ‘pucker’
- Location – around mouth - Action – purse lips together
Buccinator – ‘suck cheeks in’
- Location – cheeks - Action – cheek tension
Zygomaticus – ‘smile
- Location – corner of mouth to zygomatic bone - Action – elevate corner of mouth in a smile
Depressor labii inferioris – ‘pout’
- Location – chin and lower lip - Action – pull lower lip downward
MUSCLES OF MASTICATION
Masseter – ‘jaw muscle’ - Location – over ramus of mandible - Action – elevate mandible (close jaw)
Temporalis – ‘wiggles ears’
- Location – over temporal bone and onto parietal bone - Action – elevate mandible and can wiggle ears
MUSCLES OF THE NECK
Platysma – ‘pulls corners of mouth downward’ - Location – thin, superficial muscle over anterior neck - Action – pulls corners of mouth downward
Sternocleidomastoid – ‘diagonal neck muscle’
- Location – from mastoid process to medial aspect of clavicle and sternum - Action – flexion of head at the neck (both), or turn head to side (one at a time)
MUSCLES OF RESPIRATION INSPIRATION
Diaphragm - Location – separates the thoracic and abdominal cavities - Action – inspiration, enlarges thoracic cavity (pulls down to ‘suck’ air into lungs)
External intercostals
- Location – between ribs - Action – inspiration, elevates ribs (to increase size of chest cavity for a big
breath of air)
Scalenes – ‘deep neck muscles for big breaths’ - Location – transverse process of cervical vertebrae to first two ribs - Action – inspiration, elevates first two ribs (to increase size of chest cavity
for a big breath of air) EXPIRATION
Internal intercostals - Location – between ribs - Action – expiration, compresses ribs (decrease size of chest cavity pushing
air out)
MUSCLES OF THE TORSO ANTERIOR: ABDOMINALS
Rectus abdominis – ‘six-pack muscles’ - Location – medial, abdominal region - Action – flexion of torso, stabilization of torso
External oblique – fibers are arranged in a “V” shape
- Location – lateral and superficial torso - Action – rotation of torso, stabilization of torso
Internal oblique – fibers are arranged in an “A” shape
- Location – deep to external obliques - Action – rotation of torso, stabilization of torso
Transversus abdominis – fibers are arranged around the torso like a belt
- Location – deep to internal obliques - Action – compresses abdomen
POSTERIOR: VERTEBRAL COLUMN
Erector spinae – ‘back strap muscles’ - Location – sacrum up toward ribs - Action – extension of torso
Muscular System – Appendicular Muscles (Upper Body)
MUSCLES OF THE TRUNK: ANTERIOR POSITION PECTORAL GIRDLE
Pectoralis minor - Location – ribs 3-5 to coracoid process of scapula, deep to pectoralis major - Action – downward rotation of scapula (shoulder), stabilization of scapula
Serratus anterior
- Location – lateral part of ribs 1-9 to medial border of scapula - Action – upward rotation of scapula (shoulder), stabilization of scapula
MOVE THE ARM
Pectoralis major - Location – upper ribs and sternum to proximal humerus - Action – flexion, adduction, and medial rotation of arm
MUSCLES OF THE TRUNK: POSTERIOR POSITION PECTORAL GIRDLE
Trapezius - Location – from occipital bone and thoracic spinous processes to spine of scapula
and over shoulder to clavicle - Action – shrug shoulders, extend neck
Levator scapulae
- Location – 1st four cervical vertebrae to superior, medial border of scapula - Action – downward rotation of scapula (shoulder)
Rhomboid major & rhomboid minor
- Location – between medial border of scapula and spinous processes - Action – adduction or retraction of scapula
MOVE THE ARM
Latissimus dorsi - Location – spinous processes of lower vertebrae to proximal humerus - Action – Adduction, extension, and medial rotation of arm
Teres major
- Location – inferior angle of scapula to proximal humerus - Action – adduction, extension, and medial rotation of arm
ROTATOR CUFF MUSCLES
Supraspinatus - Location – above the spine of the scapula to behind the head of the humerus - Action – stabilization of scapula, synergist in arm abduction
Infraspinatus
- Location – below the spine of the scapula to behind the head of the humerus - Action – stabilization of scapula, synergist in lateral rotation of arm
Teres minor
- Location – lateral border of scapula to behind the head of the humerus - Action – stabilization of scapula, synergist in lateral rotation of arm
Subscapularis
- Location – the ‘under’ side of the scapula to behind the head of the humerus - Action – stabilization of scapula, synergist in medial rotation of arm
MUSCLES OF THE ARM LATERAL
Deltoid - Location – from occipital bone and thoracic spinous processes to spine of scapula
and over shoulder to clavicle - Action – arm abduction; medial and lateral rotation and extension of arm
ANTERIOR
Biceps brachii - Location – anterior (upper) arm - Action – flexion of forearm in supinated position, also (upper) arm flexion
Brachialis
- Location – deep to biceps brachii - Action – flexion of forearm in pronated position
POSTERIOR
Triceps brachii - Location – posterior (upper) arm - Action – extension of forearm (straighten elbow); extension of arm
MUSCLES OF THE FOREARM ANTERIOR
Brachioradialis - Location – lateral, distal humerus to distal portion of radius - Action – flexion of forearm with palms facing medially
Flexor carpi radialis
- Location – distal, lateral humerus to lateral wrist - Action – flexion and abduction of wrist
Flexor carpi ulnaris
- Location – medial, lateral humerus to medial wrist - Action – flexion and adduction of wrist
Palmaris longus
- Location – anterior, medial forearm - Action – flexion of hand
Flexor digitorum superficialis
- Location – anterior, medial forearm - Action – flexion of fingers and hand
Pronator quadratus
- Location – deep, distal forearm - Action – pronation
Supinator
- Location – deep, proximal forearm - Action – supination
POSTERIOR
Extensor carpi radialis longus and extensor carpi radialis brevis - Location – lateral, distal humerus to base of hand (metacarpals) - Action – extension and abduction of wrist
Extensor carpi ulnaris
- Location – medial, lateral humerus to base of hand (metacarpals) - Action – extension and adduction of wrist
Extensor pollicis longus and extensor pollicis brevis
- Location – posterior, lateral forearm to thumb - Action – extension and abduction of thumb
Muscular System – Appendicular Muscles (Lower Body)
MUSCLES OF THE PELVIC GIRDLE (HIP) GLUTEAL MUSCLES
Gluteus maximus - Location – iliac crest to gluteal
tuberosity - Action – extension, and lateral
rotation of leg
Gluteus medius - Location – anterior iliac crest
to proximal femur - Action – abduction of leg
Gluteus minimus
- Location – deep to gluteus medius
- Action – abduction, and medial rotation of leg
Tensor fascia latae
- Location – iliac crest to proximal tibia
- Action – stabilize hip and knee
LATERAL ROTATORS Piriformis
- Location – sacrum to proximal femur
- Action – abduction and lateral rotation of leg
Obturator
- Location – obturator foramen to proximal femur
- Action – lateral rotation of leg
Quadratus femoris - Location – ischial tuberosity to
proximal femur - Action – lateral rotation of leg
Superior gemellus and inferior
gemellus - Location – ischium to proximal
femur - Action – lateral rotation of leg
HIP FLEXOR
Iliopsoas - Location – iliac fossa (iliacus) and lower vertebral column (psoas major) - Action – flexion of the leg (at the hip)
ADDUCTORS
Adductor magnus, adductor longus, adductor brevis - Location – medial thigh - Action – adduction of leg
Pectineus
- Location – anterior, medial thigh - Action – flexion and adduction of leg
Gracilis
- Location – most medial thigh muscle - Action – adduction of leg, synergist in flexion at knee
MUSCLES OF THE THIGH ANTERIOR
Sartorius – ‘tailor’s muscle’ - Location – anterior superior iliac spine to medial tibia - Action – flexion at the knee and lateral rotation of thigh
ANTERIOR – QUADRICEPS FEMORIS
Vastus lateralis Vastus intermedius Vastus medialis
- Location – from femur to quadriceps tendon to patellar ligament to tibia - Action – extension of the lower leg (at the knee)
Rectus femoris - Location – from ilium to quadriceps tendon to patellar ligament to tibia - Action – extension of the lower leg (at the knee), synergist in hip flexion
POSTERIOR – HAMSTRINGS
Semimembranosus Semitendinosus Biceps femoris
- Location – from ischial tuberosity to tibia - Action – flexion of lower leg (at knee), extension of thigh (at hip)
Gastrocnemius
MUSCLES OF THE (LOWER) LEG ANTERIOR
Tibialis anterior - Location – anterior, lateral tibia (shin to middle of foot) - Action – dorsiflexion and inversion
Extensor digitorum longus
- Location – anterior, lateral tibia (shin) to toes - Action – extension of toes
Extensor hallucis longus
- Location – anterior, lateral tibia (shin) to big toe - Action – extension of big toe
POSTERIOR & LATERAL
Gastrocnemius - Location – posterior, superficial, two-headed muscle attached to Achilles tendon - Action – plantar flexion with knee straight
Soleus
- Location – posterior, deep to gastrocnemius, also attached to Achilles tendon - Action – plantar flexion with knee bent
Peroneus (fibularis) longus
- Location – lateral, superficial muscle attached to lateral foot - Action – eversion, synergist in plantar flexion
Gastrocnemius