Shoulder region

Question 1

What is the function of the shoulder region?

Answer 1

It serves as the proximal end and attachment site of the upper limb.

Question 2

What 3 body regions does the shoulder overlap with?

Answer 2

Thorax
Upper back
Lower lateral neck

Question 3

What are the three main anatomical divisions of the shoulder region?

Answer 3

Anterior – Pectoral region
Lateral – Deltoid region
Posterior – Scapular region

Question 4

What are the 4 bones of the pectoral girdle?

Answer 4

1) Manubrium sterni
2) Clavicle (collarbone)
3) Scapula (shoulder blade)
4) Humerus

Question 5

What are the 4 joints of the pectoral girdle?

Answer 5

A) Sterno-clavicular (SC) joint
B) Acromio-clavicular (AC) joint
C) Scapulo-thoracic “joint”
D) Gleno-humeral joint

Question 6

What are the 5 key anatomical features of the clavicle?

Answer 6

1) Sternal facet
2) Acromial facet
3) Trapezoid line
4) Conoid tubercle
5) Subclavian groove

Question 7

What is unique about the structure of the clavicle?

Answer 7

It has no medullary cavity and consists of trabecular (spongy) bone surrounded by a compact shell.

Question 8

What is unique about the ossification of the clavicle?

Answer 8

First bone to begin ossification in the embryo.

Last bone to complete ossification (males: 18-20 years, females: 21-25 years).

Question 9

How does the shape of the clavicle vary?

Answer 9

There is great variation in shape based on laterality (left/right) and sex.

Question 10

What are the 7 key anatomical features of the scapula?

Answer 10

Glenoid cavity
Subscapular fossa
Supraspinous fossa
Infraspinous fossa
Spine
Acromion process
Coracoid process

Question 11

What is Os Acromiale?

Answer 11

A non-union between the acromion and the neck of the scapula, occurring in 1-15% of people.

Question 12

what does akros mean in greek

Answer 12

top

Question 13

what does omos mean in greek

Answer 13

shoulder

Question 14

what does corax mean in greek

Answer 14

crow/ raven

Question 15

What type of joint is the sternoclavicular (SC) joint?

Answer 15

It is a synovial joint.

Question 16

What is the shape of the SC joint, and how does it function?

Answer 16

It is saddle-shaped, but functionally acts as a ball-and-socket joint.

Question 17

Why is the SC joint important?

Answer 17

It is the only articulation between the axial skeleton and the pectoral girdle/upper limb.

Question 18

What structures provide stability to the SC joint?

Answer 18

Articular disc
Interclavicular ligament
Costoclavicular ligament
Anterior SC ligament

Question 19

What bones articulate at the SC joint?

Answer 19

Clavicle (clavicular notch of sternum)
Manubrium of the sternum
First costal cartilage

Question 20

What type of joint is the acromioclavicular (AC) joint?

Answer 20

It is a synovial joint.

Question 21

What is unique about the articular disc in the AC joint?

Answer 21

it is incomplete.

Question 22

What is the primary function of the AC joint?

Answer 22

It allows scapular movement relative to the clavicle, contributing to full shoulder mobility.

Question 23

What 2 ligaments stabilize the AC joint?

Answer 23

cromioclavicular ligament

Coracoclavicular ligament (includes trapezoid and conoid ligaments)

Question 24

What is the coracoclavicular ligament composed of?

Answer 24

Trapezoid ligament
Conoid ligament

Question 25

why is the AC joint structurally weak?

Answer 25

There are no muscles bridging the joint, making it reliant on ligaments for stability.

Question 26

What injury is associated with the AC joint?

Answer 26

AC joint injury = separated shoulder (caused by ligament disruption).

Question 27

Answer 27

Question 28

Answer 28

Question 29

Answer 29

Question 30

Answer 30

Question 31

Answer 31

Question 32

Answer 32

Question 33

What type of joint is the glenohumeral joint?

Answer 33

It is a synovial joint.

Question 34

What is the structural classification of the glenohumeral joint?

Answer 34

It is a ball-and-socket joint.

Question 35

What is the primary function of the glenohumeral joint?

Answer 35

It allows a wide range of motion, making it the most mobile joint in the body.

Question 36

Answer 36

Question 37

What are the 5 key ligaments of the glenohumeral joint?

Answer 37

Acromioclavicular ligament Coracoclavicular ligament Coracoacromial ligament Coracohumeral ligament Glenohumeral ligaments (superior, middle, inferior)

Question 38

Where do most glenohumeral dislocations occur?

Answer 38

Anteriorly

Question 39

What nerves are at risk of injury in an anterior glenohumeral dislocation?

Answer 39

Axillary nerve Radial nerve

Question 40

What are the 3 main functions of the pectoralis major muscle?

Answer 40

Flexes the arm at the glenohumeral joint Adducts the arm Medially rotates the arm

Question 41

What are the three parts of the pectoralis major?

Answer 41

Clavicular head Sternocostal head Abdominal part

Question 42

What congenital condition is associated with pectoral muscle hypoplasia?

Answer 42

Poland’s syndrome

Question 43

What is the function of the subclavius muscle?

Answer 43

Pulls the tip of the shoulder down Protracts the scapula

Question 44

What are the 3 function of the subclavius muscle?

Answer 44

Pulls the tip of the shoulder down Stabilizes the sternoclavicular (SC) joint May cushion blood vessels and nerves passing through the axillary inlet

Question 45

What are the 4 deep posterior axio-appendicular muscles?

Answer 45

Levator scapulae Rhomboid minor Rhomboid major Serratus anterior

Question 46

What is the function of the levator scapulae, rhomboid minor, and rhomboid major?

Answer 46

They elevate, retract, and rotate the scapula.

Question 47

What is the function of the serratus anterior?

Answer 47

It protracts the scapula and is also called the ‘big swing muscle’.

Question 48

What are the 2 superficial posterior axio-appendicular muscles?

Answer 48

Trapezius Latissimus dorsi

Question 49

What are the 3 fibres of the trapezius muscle and the 3 functions?

Answer 49

Superior fibers → Elevate scapula Middle fibers → Retract scapula Inferior fibers → Depress scapula

Question 50

What are the 3 functions of the latissimus dorsi muscle?

Answer 50

Extends the arm Adducts the arm Medially rotates the arm at the glenohumeral joint

Question 51

What is the main function of the deltoid muscle?

Answer 51

It abducts the arm at the glenohumeral joint.

Question 52

What additional movements does the deltoid muscle assist with?

Answer 52

It also assists in flexing and extending the arm.

Question 53

Which muscle initiates the first 10-15 degrees of arm abduction before the deltoid takes over?

Answer 53

The supraspinatus muscle.

Question 54

What are the 5 deep intrinsic shoulder muscles?

Answer 54

Supraspinatus Infraspinatus Teres minor Teres major Subscapularis

Question 55

What is the function of the supraspinatus muscle?

Answer 55

It initiates abduction of the arm at the glenohumeral joint.

Question 56

What is the function of the infraspinatus muscle?

Answer 56

It laterally rotates the arm.

Question 57

What is the function of the teres minor muscle

Answer 57

It laterally rotates the arm.

Question 58

What is the function of the teres major muscle?

Answer 58

It medially rotates the arm.

Question 59

What is the function of the subscapularis muscle?

Answer 59

It medially rotates the arm.

Question 60

What are the 4 rotator cuff muscles?

Answer 60

Supraspinatus Infraspinatus Teres minor Subscapularis

Question 61

What are the 4 common rotator cuff injuries, typical in sports injuries?

Answer 61

Tears Tendinosis Inflammation Fibrosis

Question 62

diagram of the humerus

Answer 62

Question 63

What are the origins of the biceps brachii?

Answer 63

Long head: Supraglenoid tubercle Short head: Coracoid process

Question 64

What are the insertions of the biceps brachii?

Answer 64

Radial tuberosity Bicipital aponeurosis

Question 65

What is the primary function of the biceps brachii?

Answer 65

Supination of the forearm Flexion of the forearm at the elbow joint

Question 66

How does the function of the biceps brachii change with forearm position

Answer 66

Forearm pronated → Biceps acts as a supinator Forearm supinated at 90 degrees → Biceps acts as a flexor

Question 67

What is a common anatomical variation of the biceps brachii?

Answer 67

In 10% of people, a third head originates from the superomedial part of the brachialis.

Question 68

What is the origin of the coracobrachialis muscle?

Answer 68

Coracoid process of the scapula

Question 69

What are the 3 functions of the coracobrachialis muscle?

Answer 69

Adducts the arm at the shoulder joint Flexes the arm at the shoulder joint Stabilizes the shoulder

Question 70

What is the main function of the brachialis muscle?

Answer 70

It is the main flexor ("workhorse") of the forearm at the elbow joint.

Question 71

What is the insertion point of the brachialis muscle?

Answer 71

The coronoid process and ulnar tuberosity.

Question 72

What is the primary function of the triceps brachii?

Answer 72

It is the main extensor of the forearm at the elbow joint.

Question 73

What additional function does the long head of the triceps brachii perform?

Answer 73

The long head adducts and extends the arm at the shoulder joint.

Question 74

Where does the long head of the triceps brachii originate?

Answer 74

Infraglenoid tubercle of the scapula.

Question 75

What is the primary function of the anconeus muscle?

Answer 75

Assists the triceps brachii as an extensor of the forearm.

Question 76

What role does the anconeus play in the elbow joint?

Answer 76

It tenses the capsule of the elbow joint.

Question 77

How does the anconeus contribute to forearm movement?

Answer 77

It may abduct the ulna during pronation of the forearm.

Question 78

What anatomical variation is present in less than 25% of the population?

Answer 78

The anconeus epitrochlearis/sextus, which is replaced by the Osborne ligament.

Question 79

there is a prosection worksheet on keats for this topic