BI 231 - Anatomy and Physiology 1 Muscle List Muscles of the Head and Neck Muscle frontalis (frontal belly of occipitofrontalis) orbicularis oculi

Origin(s) epicranial aponeurosis medial margin of orbit

Insertion(s) skin of eyebrow, bridge of nose skin around eyelid

Action(s) raises eyebrows, wrinkles forehead closes eye

zygomaticus

zygomatic bone

corner of mouth

orbicularis oris

maxillary bone & mandible

lips

buccinator

orbicularis oris

masseter

alveolar processes of maxilla & mandible zygomatic arch

temporalis

temporal bone

platysma

fascia of chest (upper thorax) & neck

mandible (coronoid process) mandible & skin of cheek

retracts and elevates corner of mouth (smiling) compresses, purses lips (kissing) compresses cheeks (whistling) elevates mandible & closes jaw (primary muscle of mastication) elevates mandible

sternocleidomastoid

sternum (manubrium) & clavicle mandible & temporal bone (mastoid process) temporal bone (styloid process) mandible (mylohyoid line)

temporal bone (mastoid process) hyoid

sternum (manubrium) & clavicle sternum (manubrium) & 1st costal cartiage

hyoid thyroid cartilage of larynx

depresses hyoid bone & larynx

transverse and costal processes of cervical vertebrae

superior surfaces of first two ribs

elevate ribs or flex neck

digastric stylohyoid mylohyoid

sternohyoid sternothyroid

scalenes

lateral surface of mandibular ramus

hyoid hyoid

tenses skin of neck & depresses lower lip / mandible (frowning) flexes neck & rotates head depresses mandible & elevates larynx elevates larynx elevates floor of mouth and hyoid bone; depresses mandible depresses hyoid & larynx

Muscles of the Shoulder and Anterior Thorax Muscle serratus anterior

Origin(s) upper ribs (1-9)

Insertion(s) scapula

pectoralis major pectoralis minor

clavicle, sternum (body), & ribs (2-6) upper ribs (3-5)

humerus (greater tubercle & intertubercular groove) scapula (coracoid process)

deltoid

clavicle & scapula

humerus (deltoid tuberosity)

Action(s) protracts shoulder; upward rotation of scapula flexes, adducts, & medially rotates humerus depresses and protracs shoulder; downward rotation of scapula; elevates ribs abducts humerus; (ant.) flexes and medially rotates humerus or (post.) extends and laterally rotates humerus 1

latissimus dorsi

teres major

spinous processes of inferior thoracic and all lumbar vertebrae, ribs (812) & lumbodorsal fascia scapula (inferior angle)

teres minor

scapula (lateral border)

subscapularis

subscapular fossa of scapula

humerus (intertubercular groove)

extends, adducts, & medially rotates humerus

humerus (intertubercular groove) humerus (greater tubercle)

extends, adducts, & medially rotates humerus laterally rotates humerus

lesser tubercle of humerus

medial rotation of shoulder

Muscles of the Posterior Thorax Muscle levator scapulae

Origin(s) transverse processes of cervical vertebrae (1-4)

Insertion(s) scapula

Action(s) elevates scapula

infraspinatus

infraspinous fossa of scapula

greater tubercle of humerus

lateral rotation at shoulder

supraspinatus

supraspinous fossa of scapula

greater tubercle of humerus

abduction at the shoulder

rhomboid major

spinous processes of upper thoracic vertebrae spinous processes of vertebrae C7 to T1 occipital bone, ligamentum nuchae, and spinous processes of all thoracic vertebrae iliac crest, vertebrae, and ribs 3-6

scapula

adducts scapula & downward rotation adducts scapula & downward rotation elevates, retracts, depresses, or rotates scapula; elevates clavicle; extends neck extends vertebral column and/or neck; lateral flexion of vertebral column

rhomboid minor trapezius

erector spinae (really 3 groups of muscles)

scapula clavicle & scapula

ribs and vertebrae above the origin

Muscles of the Body Wall Muscle rectus abdominus

pubis

external oblique

ribs 5-12

internal oblique

ilium (iliac crest) and lumbodorsal fascia

Inferior ribs, xiphoid process & linea alba

transversus abdominus

ilium (iliac crest), lower ribs (6-12), and lumbodorsal fascia inferior border of each rib

linea alba & pubis

compresses abdomen, depresses ribs & flexes spine compresses abdomen, depresses ribs & flexes spine compresses abdomen

superior border of rib below

elevates ribs during inspiration

external intercostals

Origin(s)

Insertion(s) costal cartilage of ribs 5-7 & sternum (xiphoid process) ilium (iliac crest) & linea alba

Action(s) depresses ribs, flexes vertebral column

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internal intercostals

superior border of each rib

inferior border of rib above

depresses ribs during expiration

quadratus lumborum

iliac crest and iliolumbar ligament

last rib and transverse processes of lumbar vertebrae

together, depress ribs; alone flexes vertebral column laterally

diaphragm

xiphoid process, cartilages of ribs 4-10, anterior surfaces of lumbar vertebrae

central tendonous sheet

contraction expands thoracic cavity, compresses abdominopelvic cavity

Muscles of the Arm Muscle biceps brachii

Origin(s) scapula (coracoid process)

Insertion(s) radius (tuberosity)

brachialis

humerus (anterior distal surface) humerus (ridge superior to lateral epicondyle) scapula & humerus

ulna

Action(s) flexes elbow & supinates forearm (turns corkscrew & pulls cork) flexes elbow

radius (styloid process)

flexes elbow

ulna (olecranon process)

extends elbow

brachioradialis triceps brachii

Muscles of the Forearm Muscle supinator pronator teres

flexor carpi radialis flexor carpi ulnaris extensor carpi radialis longus extensor carpi ulnaris flexor digitorum superficialis extensor digitorum

Origin(s) humerus (lateral epicondyle) and ulna humerus (medial epicondyle) & ulna (coronoid process) humerus (medial epicondyle) humerus (medial epicondyle) & ulna humerus humerus (lateral epicondyle) & ulna humerus (medial epicondyle) & anterior of ulna and radius humerus (lateral epicondyle)

radius

Insertion(s)

Action(s) supinates forearm

radius

pronates forearm

base of 2nd & 3rd metacarpals pisiform, hamate, & base of 5th metacarpal base of 2nd metacarpal

flexes & abducts wrist

base of 5th metacarpal

extends & adducts wrist

midlateral surface of phalanges 2-5

flexes digits 2-5 and wrist

posterior surface of phalanges 2-5

extends digits 2-5 and wrist

flexes & adducts wrist extends & abducts wrist

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Muscles of the Hip Muscle iliopsoas (= iliacus + psoas major) gluteus maximus

Insertion(s) femur (lesser trochanter)

Action(s) flexes hip

femur & iliotibial tract

gluteus medius

Origin(s) vertebrae (T12-L5) & ilium (iliac fossa) ilium (iliac crest), sacrum, & coccyx ilium (anterior iliac crest)

gluteus minimus

ilium

femur (greater trochanter)

tensor fasciae latae

ilium (iliac crest & anterior superior iliac spine)

iliotibial tract

adductor longus

pubis (inferior ramus)

femur (linea aspera)

adductor brevis

pubis (inferior ramus)

femur (linea aspera)

adductor magnus

pubis (inferior ramus) & ischium (ischial tuberosity)

femur (linea aspera)

extends & laterally rotates thigh abducts & medially rotates thigh abducts & medially rotates thigh flexes and medially rotates thigh; tenses fascia lata which laterally supports the knee adducts, flexes, & medially rotates thigh adducts, flexes, & medially rotates thigh adducts, & medially rotates thigh

femur (greater trochanter)

Muscles of the Thigh Muscle rectus femoris

Insertion(s) tibia (tibial tuberosity) via patellar tendon

Action(s) extends knee & flexes thigh at the hip extends knee

semimembranosus

femur (proximal half of linea aspera) femur (distal half of linea aspera) ischium (ischial tuberosity) & femur (linea aspera) ischium (ischial tuberosity)

tibia (tibial tuberosity) via patellar tendon tibia (tibial tuberosity) via patellar tendon tibia (tibial tuberosity) via patellar tendon tibia (lateral condyle) & fibula (head) tibia (medial condyle)

semitendinosus

ischium (ischial tuberosity)

tibia

gracilis

pubis (inferior ramus)

tibia

sartorius

ilium (anterior superior spine)

tibia (medial surface near tibial tuberosity)

vastus medialis vastus lateralis vastus intermedius biceps femoris

Origin(s) ilium (anterior inferior spine) & rim of acetabulum femur (entire linea aspera)

extends knee extends knee flexes knee, extends & laterally rotates thigh flexes knee, medially rotates leg, & extends hip flexes knee, medially rotates leg, & extends hip flexes leg, adducts & medially rotates thigh flexes knee, flexes & laterally rotates thigh (“tailors muscle”)

Muscles of the Leg Muscle gastrocnemius

Origin(s) femur (condyles)

soleus

tibia & fibula (head)

popliteus

lateral condyle of femur

Insertion(s) calcaneous via calcaneal tendon calcaneous via calcaneal tendon

Action(s) plantar flexes foot, inverts foot, and flexes knee plantar flexes foot

posterior surface of proximal tibial shaft

medial rotation of tibia; flexion at knee

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peroneus (fibularis) longus

lateral condyle of tibia & fibula

base of 1st metatarsal & medial cuneiform bone

peroneus (fibularis) brevis tibialis anterior

fibula tibia (lateral condyle)

tibialis posterior

tibia and fibula

base of 5th metatarsal base of 1st metatarsal & medial cuneiform bone tarsals and metatarsals

flexor digitorum longus

tibia

extensor digitorum longus

tibia (lateral condyle) & fibula

inferior surface of phalanges 2-5 superior surface of phalanges 2-5

plantar flexes & everts foot; supports longitudinal arch plantar flexes & everts foot dorsiflexes & inverts foot adducts, inverts, and plantar flexes foot flexes toes 2-5 extends toes 2-5

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