API Notes Home Page

Muscular Anatomy: Muscles of the Shoulder & Arm

I). Movements of the Scapula----Muscles of the External Thorax

A).  Anterior:  Protracts

1). Pectoralis minor

Location

 

Function

 

O:  rib cage

 

I:  scapula

named for regional location and relative size

2). Serratus anterior

Location

 

Function

O:  rib cage

 

I:  scapula

named for serrated shape (like a saw) and direction (anterior)

serratus anterior

B).  Posterior Thorax: Retracts

1). Trapezius

Location

 

Function

O:  occipital bone & vertebrae

 

I: scapula

named for shape 4-sided diamond shape called a trapezoid

trapeizius
2). Rhomboids

Location

 

Function

 

O: vertebrae

 

I: scapula

named for 4 sided shape with parallel sides-rhomboid

rhomboids

II).  Crossing the Shoulder Joint

A). Pectoralis Major

Location

 

Function

O:  sternum

I:  humerus

named for regional location and relative size

pectoralis major
 

B). Latissimus Dorsi

Location

 

Function

O: vertebrae

 

I: humerus

named for latis means 'broad' dorsi means 'back'--broad muscle of the back.

latissimus dorsi
C). Deltoid

 

O:  clavicle and scapula

 

I:  humerus

named for shape Greek letter delta-triangle

deltoid
D). Infraspinatus

Location

 

Function

O: scapula

 

I: humerus

named for location in relation to scapular spine.

infraspinatus
E). Supraspinatus

Location

Function

O: scapula

 

I: humerus

named for location in relation to scapular spine.

supraspinatus
F). Teres Major

 

Location

Function

O: scapula

 

I: humerus

named teres means rounded and it it larger then the teres minor so it is larger round muscle.

G). Teres Minor

Location

Function

O: scapula

 

I: humerus

named teres means rounded and it is smalled then the teres major

H). Coracobrachialis

Location

 

Function

O: scapula

I: medial humerus

named for origin coracoid process and insertion brachial region.

coracobrachialis

III). Crossing the Elbow Joint

A). Anterior:  Flexors

1). Biceps Brachii

Location

 

Function

O: scapula & humerus

 

I:  radius

named for 2 origins (bicep) and region.

bicep brachi
2). Brachialis

Location

 

Function

O: humerus

I:  ulna

named for regional location

brachiallis
3). Brachioradialis

Location

 

Function

O:  humerus (distal)

 

I:   radius (distal)

named for origin and insertion

brachioradialis

B). Posterior: Extenders

 
1). Triceps Brachii

Location

Function

O:   scapula & medial and proximal humerus

 

I:  radius

named for 3 origins and location

tricep brachii

IV). Forearm:  Movement of the wrist

A.  Anterior

1). Pronator Teres

Location

 

Function

O: humerus

 

I:  radius

named for function and round shape

pronator teres
2).  Pronator quadratus

Location

 

Function

O:  ulna

 

I:  radius

named for function and square shape

pronator quadratus
 3). Palmaris Longus

Location

 

Function

O: humerus

 

I:  palm

named for its insertion and length

 

palmaris longus
4). Flexor Carpi Radialis

Location

 

Function

O:  humerus

I:   carpals along radius

named for function, insertion and local bone.

flexor carpi radialis
5). Flexor Carpi Ulnaris

Location

 

Function

O:  humerus

I:   carpals along ulna

named for function, insertion and local bone

flexor carpi ulnaris

B). Posterior

1). Supinator

Location

 

Function

O:  humerus & ulna

 

I:  medial radius

named for function

 

supinator

2). Extensor Carpi Radialis

(Longus & Brevis)

Location

 

Function

O:  humerus

 

I:  carpals along radius

named for function, insertion and local bone

extensor carpi radialis
3). Extensor Carpi Ulnaris

Location

 

Function

O:  humerus & ulna

I: carpals along ulna

named for function, insertion and local bone

 

extensor carpi ulnaris

V).  Movements of the Fingers

A).  Anterior:  Flexors

Flexor Digitorum Superficialis

Location

 

Function

O:  ulna

 

I:  phalanges

named for function and insertion

flexor digitorum

B) Posterior:  Extenders  
Extensor Digitorum

Location

 

Function

O:  humerus

 

I:  phalanges

named for function and insertion

 

extensor digitorum

 

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