UNIT 2 SECOND ORDER

Pectoralis major function

• agonist of arm flexion

• adducts arm

• medially rotates arm

• clavicular head = flexion

• sternal coastal head = extension of humerus

Pectoralis major innervation

medial & lateral pectoral N

Pectoralis major origin

• clavicle

• ribs

• sternum

Pectoralis major insertion

humerus

Coracobrachialis function

flexes & adducts arm

Coracobrachialis innervation

musculocutaneous N

Coracobrachialis origin

scapula

Coracobrachialis insertion

humerus

Biceps brachii function

• flexes arm (weakly)

• supinates forearm when elbow is flexed

Biceps brachii (long head) innervation

musculocutaneous N

Biceps brachii origin

scapula

Biceps brachii (long head) insertion

radial tuberosity

Triceps brachii (long head) function

• extends arm

• adducts arm

Triceps brachii (long head) innervation

radial N

Triceps brachii (long head) origin

scapula

Triceps brachii (long head) insertion

ulna

Brachioradialis function

flexes forearm in midposition

Brachioradialis innervation

radial N

Brachioradialis origin

humerus

Brachioradialis insertion

radius

Rectus femoris function

• flexes thigh

• extends leg at knee joint

*crosses hip joint

Rectus femoris innervation

femoral N

Rectus femoris origin

iliac spine

Rectus femoris insertion

• quadriceps tendon to patella

• patellar ligament to tibial tuberosity

Adductor longus function

adducts & flexes thigh

Adductor longus innervation

obturator N

Adductor longus origin

pubis near pubic symphysis

Adductor longus insertion

femur

Tibialis anterior function

• dorsiflexes foot

• inverts foot

Tibialis anterior innervation

deep fibular N

Tibialis anterior origin

tibia

Tibialis anterior insertion

metatarsal 1

Semitendinosus function

• extends thigh & flexes leg at the knee joint

• medially rotates leg when flexed at knee

Semitendinosus innervation

sciatic N

Semitendinosus origin

ischial tuberosity

Semitendinosus insertion

tibia

Gastrocnemius function

• flexes leg at the knee joint

• plantar flexes foot

Gastrocnemius innervation

tibial N

Gastrocnemius origin

femur

Gastrocnemius insertion

calcaneus

Lumbricals (foot) function

flexes MP joints and extends PIP and DIP joints for toes 2-5

Lumbricals innervation

medial & lateral plantar N

Lumbricals (foot) origin

tendons of flexor digitorum longus

Lumbricals (foot) insertion

tendons of extensor digitorum longus

Flexor digitorum superficials function

• flexes hand at the wrist

• flexes MP joints

• flexes PIP joints of fingers 2-5

Flexor digitorum superficials innervation

median nerve

Flexor digitorum superficials insertion

middle phalanges of fingers 2-5

Flexor digitorum profundus function

• flexes hand at the wrist

• flexes MP and PIP joints

• flexes DIP joints of fingers 2-5

Flexor digitorum profundus innervation

• median nerve (lateral one half)

• ulnar nerve (medial one half)

Flexor digitorum profundus insertion

distal phalanges of fingers 2-5

Fibularis longus function

• everts foot

• weak plantar flexor of foot

Fibularis longus innervation

superficial fibular nerve

Fibularis longus insertion

• base of metatarsal I

• medial cuniform bone

Brachialis function

flexes forearm

Brachialis innervation

musculocutaneous N

Brachialis origin

humerus

Brachialis insertion

ulna

Pronator teres function

pronates forearm

Pronator teres innervation

median N

Pronator teres origin

humerus

Pronator teres insertion

radius

Opponens pollicis function

opposition of thumb

Opponens pollicis innervation

median N

Opponens pollicis origin

trapezium

Opponens pollicis insertion

lateral side of metacarpal 1

Abductor digiti minimi function

abducts finger 5

Abductor digiti minimi innervation

ulnar N

Abductor digiti minimi origin

pisiform bone

Abductor digiti minimi insertion

proximal phalanx of finger 5

Vastus medialis function

extends leg

Vastus medialis innervation

femoral N

Vastus medialis origin

femur

Vastus medialis insertion

quadriceps tendon to patella, patellar ligament to tibial tuberosity

Fibularis brevis function

• everts foot

• plantar flexes foot

Fibularis brevis innervation

superficial fibular N

Fibularis brevis origin

fibula

Fibularis brevis insertion

base of metatarsal 5

Tibialis posterior function

• plantar flexes foot

• inverts foot

Tibialis posterior innervation

tibial N

Tibialis posterior origin

tibia

Tibialis posterior insertion

metatarsals 2-4

Abductor hallucis function

abducts great toe

Abductor hallucis innervation

medial plantar N

Abductor hallucis origin

calcaneus

Abductor hallucis insertion

medial side of proximal phalanx of great toe

Flexor digiti minimi brevis function

flexes MP joint of toe 5

Flexor digiti minimi brevis innervation

lateral plantar N

Flexor digiti minimi brevis origin

metatarsal 5

Flexor digiti minimi brevis insertion

proximal phalanx of toe 5