Anatomy & Physiology (LAB 6) - Muscles PT.2: Muscles of the Extremeties

muscles from spring 2024 muscle addendum *** = deep muscle

Supraspinatus

initiates abduction of arm; innervated by subscapular nerve

o- supraspinous

i- greater tubercle of humerus

Infraspinatus

rotates arm laterally; innervated by subscapular nerve

O- supraspinous fossa

I- greater tubercle of humerus

Teres Minor

same actions as teres major; innervated by axillary nerve

O- lateral border

I- greater tubercle of humerus

Teres Major

extends, medially rotates, & adducts arm; innervated by lower subscapular nerve

o- posterior scapula

i- greater tubercle of scapula

Subscapularis

rotates arm medially; innervated by subscapular nerves

o- subscapular fossa

i- lesser tubercle of humerus

Biceps Brachii

flexes & supinates forearm; innervated by musculocutaneous nerve

o- superior part of humerus

i- radial tuberosity

Brachialis

forearm flexor; innervated by musculocutaneous nerve

o- distal humerus

i- coronoid process of ulna

Brachioradialis

helps to flex forearm; innervated by radial nerve

Coracobrachialis

flexes & adducts arm; innervated by musculocutaneous nerve

Triceps Brachii

forearm extensor; innervated by radial nerve

Pronator Teres

pronates arm; innervated by median nerve

Flexor Carpi Radialis

powerful flexor of hand; innervated by median nerve

Palmaris Longus

tenses skin & fascia of palm during hand movements; innervated by median nerve

Flexor Carpi Ulnaris

powerful flexor & adductor of hand; innervated by ulnar nerve

Flexor digitorum superficialis

flexes hand & middle phalanges of 2nd-5th fingers; innervated by median nerve

Flexor digitorum profundus***

flexes distal interphalangeal joints; innervated by ulnar & median nerves

Flexor pollicis longus***

flexes distal phalanx of thumb; innervated by median nerve

medial epicondyle of the humerus

ORIGIN OF ANTERIOR FOREARM MUSCLES

Golfer’s Elbow

medial epicondylitis

Anterior forearm muscles are…

flexors & pronators (wrist/finger movement)

Extensor Carpi Radialis Longus & Brevis

extends & abducts hand; innervated by radial nerve

Extensor digitorum

prime mover of finger extension; innervated by posterior interosseous nerve

Extensor Carpi ulnaris

extends & adducts hand; innervated by posterior interosseous nerve

Supinator***

assists biceps brachii for forcibly supinate forearm; innervated by posterior interosseous nerve

Abductor pollicis longus***

abducts & extends thumb; innervated by posterior interosseous nerve

extensor pollicis***

extends thumb; innervated by posterior interosseous nerve

Extensor retinacula

wrist band

lateral epicondyle of the humerus

ORIGIN OF POSTERIOR FOREARM MUSCLES

Tennis elbow

lateral epicondylitis

extensors & supinators

the posterior forearm muscles are…

Carpal tunnel syndrome

caused by damage of median nerve

Flexor pollicis brevis***

abducts thumb; innervated by median nerve

Abductor digiti minimi

abducts little finger; innervated by ulnar nerve

Flexor digiti minimi brevis***

flexes little finger; innervated by ulnar nerve

Opponens digiti minimi

helps in opposition; innervated by ulnar nerve

Opponens pollicis***

opposition; innervated by median nerve

Adductor pollicis

adducts & helps to oppose thumb; innervated by ulnar nerve

Palmar interossei***

adducts fingers; innervated by ulnar nerve

Dorsal intersossei

abduct fingers; innervated by ulnar nerve

Iliopsoas***

includes iliacus & psoas major;

Iliacus

prime mover for flexing thigh, or for flexing trunk on thigh; innervated by femoral nerve

Psoas Major

also flexes vertebral column laterally; innervated by ventral rami

Sartorius

flexes, abducts, & laterally rotates thigh; innervated by femoral nerve

Gluteus maximus

major extensor of thigh; innervated by inferior gluteal nerve

Gluteus medius***

abducts & medially rotates thigh; innervated by superior gluteal nerve

Gluteus minimus***

same functions as gluteus medius; innervated by superior gluteal nerve

Piriformis***

rotates extended thigh laterally; innervated by S1

Buttocks site

Intramuscular site of injections is…

Pectineus***

adducts, flexes, & medially rotates thigh; innervated by femoral nerve

Adductor longus***

adducts, flexes, & medially rotates thigh; innervated by obturator nerve

Adductor brevis***

adducts, flexes, & medially rotates thigh; innervated by obturator nerve

Adductor magnus***

adducts, flexes, & medially rotates thigh; innervated by obturator & sciatic nerve

Gracilis

adducts, flexes, & medially rotates thigh; obturator nerve

Obturator nerve

All adductors in the medial compartment of the thigh are innervated by the….

Rectus femoris

extends leg & flexes thigh at hip; innervated by femoral nerve

Vastus lateralis

site of intramuscular injections; extends leg & stabilizes knee; innervated by femoral nerve

Vastus medialis

extends leg; innervated by femoral nerve

Vastus intermedius***

extends leg; innervated by femoral nerve

femoral nerve

quadriceps innervated by the

patellar ligament & tendon

connects the bottom of the kneecap (patella) to the top of the shinbone (tibia)

Biceps femoris

extends thigh & flexes leg; innervated by sciatic nerve

Semitendinosus

extends thigh & flexes leg; innervated by sciatic nerve

Semimembranosus

extends thigh & flexes leg; innervated by sciatic nerve

Tensor fascia latae

steadies leg & trunk on thigh by tightening iliotibial tract; innervated by superior gluteal nerve

Iliotibial band

extends as a tendinous band from iliac crest to knee

Tibialis anterior

prime mover of dorsiflexion; innervated by deep fibular nerve

Extensor digitorum longus

prime mover of toe extension; innervated by deep fibular nerve

Peroneus/fibularis

dorsiflexes & everts foot; innervated by deep fibular nerve

Extensor hallucis longus***

extends great toe; innervated by deep fibular nerve

Tibialis posterior***

prime mover of foot inversion; innervated by tibial nerve

Flexor digitorum

planter flexes & inverts foot; innervated by tibial nerve

Flexor hallucis longus***

flexes great toe at all joints; innervated by tibial nerve

Flexor hallucis brevis (fibularis brevis)

plantar flexes & everts foot

Triceps surae

includes gastronemius & soleus

Gastronemius

plantar flexes foot; innervated by tibial nerve

Soleus***

plantar flexes foot; innervated by tibial nerve

Achilles/Calcaneal tendon

tendon at back of leg right above ankle

Retinacula (ankle brackets)

thickenings of deep fascia in region of joints, to keep tendons in place as they cross the joints

Dorsal interossei***

abduct toes

Plantar interossei***

adduct toes