anatomy of the shoulder

Question 1

which ligaments stabilize the pectoral gurdle?

Answer 1

• corococlavicular
• acromioclavicular
• glenohumeral- superior, middle and inferior

Question 2

what does the coracoacromial ligament do?

Answer 2

forms an arch whcih supports the head of the humerus

also prevents superior disclocation

Question 3

what movements can you have at glenohumeral joint?

Answer 3

• adduction and abduction
• flexion and extention
• lateral and medial rotation
• circumduction

Question 4

what is the action preformed by the deltoid?

Answer 4

• abduction of arm

Posterior fibres:

• Extension + lateral rotation

Anterior fibres:

• Flexion + medial rotation

Question 5

what are the origins and insertions of deltoid?

Answer 5

Origin: Spine of scapula + acromion + clavicle

Insert: Deltoid tuberosity

Question 6

what muscles are important for abduction of the arm?

Answer 6

• deltoid
• latissimus dorsi
• pectoralis major

Question 7

how is the glenohumeral joint aften disslocated?

Answer 7

anterior dislocation

Question 8

what 5 factors increase the stability of the glenohumeral joint?

Answer 8

1. coracoacromial arch
2. , glenohumeral ligaments
3. deepening of glenoid fossa by glenoid labrum
4. long head of biceps above and triceps below
5. tendons of the rotator cuff muscles

Question 9

what does the coracoacromial ligament prevent?

Answer 9

superior dislocation

Question 10

what do the glenohumeral ligaments prevent?

Answer 10

superior medial and inferor glenoid ligaments support the anterior of the joint

Question 11

what is the function of thr glenoid labrum?

Answer 11

deepens the glenoid fossa for articulation

Question 12

how is the glenohumeral joint splinted?

Answer 12

• origin of the long head of the biceps is supraglenoid tubercle
• origin of the long head of triceps is the infraglenoid tubercle
• both together splint the joint

Question 13

which 4 muscles fuse with the joint capsule to make the rotator cuff muscles?

Answer 13

• supraspinatous
• infraspinatous
• teres minor

and subscapularis

Question 14

which rotator cuff muscles are posterior?

Answer 14

• supraspinatous
• infraspinatous
• teres minor

Question 15

which rotator cuff mucles are anterior?

Answer 15

subscapularis

Question 16

what are the functions of the rotator cuff muscles?

Answer 16

supraspinatous-initiate abduction

infraspinatous- lateral rotation

teres minor- lateral rotation

subscapularis- medial roation

Question 17

what is the orifin and insertion of teres major?

Answer 17

origin- inferior angle of scapula

insertion- medial lip of bicipital groove

Question 18

what are the functions of teres major?

Answer 18

• medial rotation
• stabilisation of shoulder during abduction (eccentric cintraction)

Question 19

what is a common rotator cuff injury?

Answer 19

• supraspinatous- due to repeated overhead activities
• happenes because limited space for tendon under the corocoacromial arch

Question 20

what is the blood supply to the rotator cuffs?

Answer 20

• scapular anastamosis of the subclavian and axillary arteries

Question 21

what is the nerve supply to the rotator cuff muscles?

Answer 21

suprascapular nerve- branch from superior trunk goes to supraspinatous and infraspinatous

shoulder region is also supplies by the posterior cord;

Question 22

what do the different branches of the posterior cord innervate?

Answer 22

deltoid and teres minor- axillary

triceps brachii- radial

upper and lower subscapular nerves- subscapularis and teres major

thoracodorsal nerve- latisimus dorsi

Question 23

what are the borders of the quadrangular space?

Answer 23

superior- teres minor

inferior- teres major

lateral- humerus

medial- long head of triceps

Question 24

what structures are found in the quadrangular space?

Answer 24

• axillary nerve
• axillary artery

Question 25

what is the clinical significance of the quadrangualr space?

Answer 25

if you fracture the surgical neck of the humerus it can dammage the nerve and vessle

Question 26

what does the axillary nerve supply?

Answer 26

deltoid, teres minor and sensory to the badge area

Question 27

what is the nerve supply of pec major?

Answer 27

lateral pectoral nerve from the lateral cord of the brachial plexus

Question 28

what is the nerve supply to pec minor?

Answer 28

medail pectoral nerve from the medial cord