Anatomy of the Shoulder Region

Question 1

What makes up the pectoral girdle?

Answer 1

The clavicle and scapula

Question 2

What is the bicipital groove also known as?

Answer 2

Intertubercular sulcus

Question 3

Where is the lesser tubercle located with respect to the greater tubercle?

Answer 3

Lesser tubercle is medial to the greater tubercle

Question 4

What are the ligaments of the shoulder region?

Answer 4

• Coracoclavicular (major stabilising ligament and has 2 parts)
• Acromioclavicular
• Coracoacromial (supports the humeral head and prevents superior dislocation)
• Glenohumeral (superior, middle and inferior)

Question 5

What type of joint is the glenohumeral joint?

Answer 5

Ball and socket joint

Question 6

What movements does the glenohumeral joint allow for?

Answer 6

• Abduction / Adduction
• Flexion / Extension
• Lateral and Medial rotation
• Circumduction

Question 7

What is the origin, insertion and innervation of the deltoid muscle?

Answer 7

Origin: Spine of scapula + acromion + clavicle

Insertion: Deltoid tuberosity \

Innervation: Axillary nerve

Question 8

What are the fibres of the deltoid muscle and what is their function?

Answer 8

Anterior fibres: Flexion and medial rotation

Posterior fibres: Extension and lateral rotation

Question 9

What muscles allow for the adduction of the arm?

Answer 9

Latissimus dorsi and pectorals major

Question 10

Which muscles are able to flex the arm?

Answer 10

• Biceps (long and short head)
• Coracobrachialis
• Anterior fibres of the deltoid
• Brachialis

Question 11

Which muscles are able to extend the arm?

Answer 11

• Triceps (long, lateral and medial head)
• Latissimus dorsi
• Posterior fibres of the deltoid

Question 12

What factors increase the stability of the shoulder?

Answer 12

• Coracoacromial arch
• Glenohumeral ligaments
• Long head of biceps (above) and triceps (below)
• Deepening of the glenoid fossa by the glenoid labrum
• Rotator cuff muscles

Question 13

What makes up the coracoacromial arch?

Answer 13

Acromion and coracoacromial arch

Question 14

What is the origin of the long head of the biceps and triceps?

Answer 14

Long head of biceps = Supraglenoid tubercle

Long head of triceps = Infraglenoid tubercle

Question 15

What are the 4 rotator cuff muscles?

Answer 15

• Supraspinatus
• Infraspinatus
• Subscapularis
• Teres minor

Question 16

What is the quadrangular space?

Answer 16

An inter muscular space through which the axillary nerve, posterior circumflex artery and humeral artery pass through?

Question 17

What are the borders of the quadrangular space?

Answer 17

Superior = Teres major

Inferior = Teres minor

Medial = Long head of triceps

Lateral = Surgical neck of humerus

Question 18

Where is the anatomical neck of the humerus located with respect to the surgical neck of the humerus?

Answer 18

Superiorly

Question 19

Which rotator cuff muscles insert onto the greater tubercle of the humerus?

Answer 19

Supraspinatus
Infraspinatus
Teres minor

Question 20

Which rotator cuff muscles inserts onto the lesser tubercle?

Answer 20

Subscapularis

Question 21

What is the function of each of the rotator cuff muscles?

Answer 21

Supraspinatus: Initiates abduction

Infraspinatius: Lateral rotation

Teres minor: Lateral rotation

Subscapularis: Medial rotation

Question 22

What movement does the teres major allow for?

Answer 22

Medial rotation

Question 23

What three nerves arise from the posterior cord of the brachial plexus?

Answer 23

• Upper and Lower subscapular nerves (innervate subscapularis and teres major)
• Thoracodorsal nerve (innervates latissimus dorsi)

Question 24

Which nerve innervates the triceps brachii?

Answer 24

Radial nerve

Question 25

Which nerve innervates the deltoid and teres minor?

Answer 25

Axillary nerve

Question 26

Which cord does the musculocutaneous nerve arise from and what type of muscles does it innervate?

Answer 26

Arises from the lateral cord

Innervates the arm flexors

Question 27

Which cord does the lateral pectoral nerve arise from and which muscle does it innervate?

Answer 27

Lateral cord

Pectoralis major

Question 28

Which cord does the medial pectoral nerve arise from and which muscles does it innervate?

Answer 28

Medial cord

Pectoralis major and minor