Shoulder region muscles - PowerPoint Presentation

Slide1

Shoulder region musclesSlide2

Coracobrachialis

Adduction of the

shoulder & flexion.Slide3

Pectoralis

Major

The first action is flexion of the

humerus

,

Secondly

, it adducts the

humerus

.

Thirdly, it rotates the

humerus

medially.

Finally it aids in deep inspirationSlide4

Subscapularis

Internal rotation of the shoulderSlide5

Deltoid

Abduction of shoulderSlide6

Infraspinatus

External rotationSlide7

Teres Major

Adduction of scapulaSlide8

Teres

Minor

The

infraspinatus

and

teres

minor attach to head of the

humerus

; as part of the rotator

cuff they

help hold the humeral head in the

glenoid

cavity of the scapula. They work in tandem with the posterior deltoid to externally (laterally) rotate the

humerus

, as well as perform transverse abduction, extension and transverse extension.Slide9

Supraspinatus

Abduction of the shoulderSlide10

Coracobrachialis

Pect. Major

Subscapularis

DeltoidSlide11

Supraspinatus

Teres Major

Infraspinatus

Teres MinorSlide12

Practice

List the muscles that do

flexion

of the shoulder

CoracobrachialisPectoralis major (upper to part)Anterior

Deltoid

Biceps

List the muscles that do

extension

of the shoulder

Latissimus dorsi

Teres major

Posterior deltoid

Pectoralis major (lower fibers to neutral)Slide13

Practice

List the muscles that do

adduction

of the shoulder

Pectoralis major (lower and upper below 90°)CoracobrachialisLatissimus dorsiTeres major

List the muscles that do

abduction

of the shoulder

Deltoid (all sections)

Supraspinatus

Pectoralis major (upper past 90°)Slide14

Practice

List the muscles that do

internal rotation

of the shoulder

SubscapularisLatissimus dorsiTeres majorAnterior deltoidPect. major

List the muscles that do

external rotation

of the shoulder

Infraspinatus

Teres minor

Posterior deltoidSlide15

Questions

What muscle works closely with the anterior deltoid?

Pectoralis major

What muscle is involved in any lifting movements?

DeltoidWhat is the major (strongest) extensor muscle?

Latissimus Dorsi

Name the four rotator cuff muscles.

Subscapularis, Supraspinatus, Infraspinatus, and Teres minor

.

What muscle works closely with the infraspinatus?

Teres minorSlide16

Axillary regionSlide17

The

axilla

, or armpit, is a pyramidshaped space between the upper part of the arm and the side of the chest.

Realize that the upper end, or apex, is directed into the root of the neck and is bounded anteriorly by the clavicle, posteriorly by the upper border of the scapula, and medially by the outer border of the first rib. The lower end, or base, is bounded anteriorly by the anterior axillary fold (formed by the lower border of the pectoralis major muscle), behind by the posterior axillary fold (formed by the tend of latissimus dorsi and the teres major muscle), and medially by the chest wall.

Slide18
Slide19
Slide20

Walls of the Axilla

.

Identify the structures forming the walls of the axilla:Slide21

Anterior wall

.

This is formed by the

pectoralis major,

pectoralis minor, clavipectoral fascia, and

subclavius

muscleSlide22
Slide23
Slide24

Posterior wall

.

From above downward this wall is formed by the

subscapularis,

latissimus dorsi, and the

teres

major muscles.Slide25
Slide26

Medial wall

.

This is formed by the upper four or five ribs and the intercostal spaces covered by the serratus anterior muscle.Slide27
Slide28

Lateral wall

.

This is formed by the coracobrachialis and biceps muscles in the bicipital groove of the humerus.Slide29
Slide30

Axillary

Sheath

.

The

axillary artery (but not the vein) and the brachial plexus are enclosed in a fascial sheath derived from the

prevertebral

layer of deep cervical fascia in the neck. Slide31

Axillary Artery

.

This commences at the outer border of the first rib as a continuation of the subclavian artery. Having passed through the axilla, it becomes the brachial artery at the lower border of the teres major muscle. It is

arbitrarily divided into three parts by the pectoralis minor muscle that crosses it anteriorly. Slide32
Slide33

Brachial Plexus

. Slide34

Brachial

plexus

The brachial plexus is divided into Roots, Trunks, Divisions, Cords, and Branches. There are five "terminal" branches and numerous other "pre-terminal" or "collateral" branches that leave the plexus at various points along its length.

The five 

roots

 are the five 

anterior

rami

 of the 

spinal nerves

, after they have given off their segmental supply to the muscles of the 

neck

.

These roots merge to form three 

trunks

:

"superior" or "upper" (

C5

-

C6

)

"middle" (

C7

)

"inferior" or "lower" (

C8

-

T1

)Slide35

Brachial plexus

Each trunk then splits in two, to form six 

divisions

:anterior divisions of the upper, middle, and lower trunksposterior divisions of the upper, middle, and lower trunks

These six divisions will regroup to become the three cords. The cords are named by their position with respect to the axillary

artery

.

The 

posterior cord

 is formed from the three posterior divisions of the trunks (C5-T1)

The 

lateral cord

 is the anterior divisions from the upper and middle trunks (C5-C7)

The 

medial cord

 is simply a continuation of the anterior division of the lower trunk (C8-T1)

The 

branches

are shown in the following diagramSlide36
Slide37
Slide38
Slide39

Thank You