Intro to muscles, upper limb muscle anatomy

Muscles attach to bones or other structures via

tendons

attachment point on bone/structure that is more stable, normally most proximal or medial attachment

Origin

attachment point to bone/structure that is more movable, normally most distal

or lateral attachment

Insertion

the primary muscle performing a specific action

Agonist

the muscle(s) performing the opposite action

Antagonist

muscles that aid, adjust, and/or stabilize the action of the agonist

Synergists

muscle fibers arranged in rin

Circular

muscle fibers have broad origin that converge to single insertion poin

Convergent

expanded muscle belly that tapers at ends

Fusiform

fibers run parallel, creating strap-like muscles

Parallel

fibers meet tendon at an angle

Pennate

a muscle that crosses on the anterior side of a joint produces

flexion

a muscle that crosses on the ______ side of a joint produces flexion

anterior

a muscle that crosses on the posterior side of a joint produces

extension

a muscle that crosses on the ______ side of a joint produces extension

posterior side

a muscle that crosses on the lateral side of a joint produces

abduction

a muscle that crosses on the ____ side of a joint produces abduction

a muscle that crosses on the medial side of a joint produces

adduction

a muscle that crosses on the ____ side of a joint produces adduction

connective tissue membrane that bundles structures together in the body

fascia

muscles are grouped together enveloped in

fascial compartments

what is this

trapezius

what is this

levator scapulae

what is this

teres major

what is this

rhomboid minor

what is this

rhomboid major

what is this

latissimus dorsi

trapezius action

elevates, depresses, and retracts scapula

latissimus dorsi action

extends, adducts, and medially rotates arm at shoulder

teres major action

extends, adducts, and medially rotates arm at shoulder

rhomboids major and minor action

retracts scapula and rotates it downward

levator scapulae action

elevates scapula and rotates it downward

pectoralis major action

flexes, adducts, and medially rotates arm at shoulder

pectoralis minor action

depresses scapula, holds scapula against rib cage

serratus anterior function

protracts scapula and rotates it upward

deltoid action

abduction, flexion, extension, medial rotation, and lateral rotation of shoulder

supraspinatus origin

supraspinous fossa

supraspinatus insertion

greater tubercle of humerus

supraspinatus action

abduction of arm at shoulder

infraspinatus origin

infraspinous fossa

infraspinatus insertion

greater tubercle of humerus

infraspinatus action

lateral rotation of arm at shoulder

teres minor origin

lateral border of scapula

teres minor insertion

greater tubercle of humerus

teres minor action

lateral rotation of arm at shoulder

subscapularis origin

subscapular fossa

subscapularis insertion

lesser tubercle of humerus

subscapularis action

medial rotation of arm at shoulder

shoulder abduction is carried out by

trapezius, serratus ansterior, deltoid, and supraspinatus

coracobrachialis origin

coracoid process

coracobrachialis insertion

shaft of humerus

coracobrachialis function

flexion of arm at shoulder

biceps brachii origin

scapula

biceps brachii insertion

radial tuberosity

biceps brachii function

flexion of forearm at elbow, flexion of arm at shoulder, supination of forearm

brachialis origin

shaft of humerus

brachialis insertion

ulnar tuberosity

brachialis function

flexion of forearm at elbow

triceps brachii origin

scapula and humerus

triceps brachii insertion

olecranon process of ulna

triceps brachii function

extension of forearm at elbow, extension of arm at shoulder (long head only)

anterior compartment of forearm layers

superficial- 4 muscles, intermediate- 1 muscle, deep- 3 muscles

flexes wrist

flexor carpi radialis

pronates forearm

pronator teres

tenses skin of palm

palmaris longus

flexes wrist

flexor carpi ulnaris

flexes digits #2-5 at proximal interphalangeal join

Flexor digitorum superficialis

pronates forearm

pronator quadratus

flexes thumb

flexor pollicis longus

flexes digits 2-5 at distal interphalangeal joint

flexor digitorum profundus

posterior compartment of forearm layers

mobile wad- 3 muscles, superficial layer- 3 muscles. deep layer- 5 muscles

what is this

flexor carpi ulnaris

what is this

mobile wad

extends wrist

extensor carpi radialis brevis

flexes forearm at elbow when forearm is in neutral position

brachioradialis

extends wrist

extensor carpi radialis longus

extends 5th digit

extensor digiti minimi

extends wrist

extensor carpi ulnaris

extends digits 2-5

extensor digitorum

what is this

extensor digiti minimi

what is this

flexor carpi ulnaris

extends thumb

extensor pollicis longus

abducts thumb

abductor pollicis longus

supinates forearm

supinator

extends thumb

extensor pollicis brevis

extends 2nd digit

extensor indicis

Flexor carpi radialis + flexor carpi ulnaris =

wrist flexion

Extensor carpi radialis (longus and brevis) + extensor carpi ulnaris =

wrist extension

Flexor carpi radialis + extensor carpi radialis (longus and brevis) =

wrist abduction

Flexor carpi ulnaris + extensor carpi ulnaris =

wrist adduction

what is this?

flexor digitorum superficalis tendons

palmar interossei (3) adduct digits, dorsal interossei (4) abduct digits “PAD DAB”

Interossei muscles

flexes, abducts, and opposes thumb

thenar muscle group

flexes, abducts, and opposes 5th digit

hypothenar muscle group