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