Lecture 4: Bones and Joints of the Pectoral Girdle

Question 1

What does the pectoral girdle refer to?

Answer 1

The scapula and clavicle

Question 2

What is the structure of the clavicle?

Answer 2

S-shaped bone that connects the upper limb to the trunk
Medial half of the bone is convex anteriorly
Lateral half of the bone is concave anteriorly

Question 3

Where does the clavicle articulate medially and laterally?

Answer 3

Medially: with the manubrium of the sternum
Laterally: with the acromion of the scapula

Question 4

What is the texture of the clavicle?

Answer 4

Superior: smooth
Inferior: rough due to bone markings from ligaments and muscles

Question 5

What is the structure of the scapula?

Answer 5

Triangular shaped-bone that lies on the posterior aspect of the rib cage

Question 6

What does the humerus articulate with?

Answer 6

The glenoid fossa/cavity

Question 7

What does the scapula provide for muscles?

Answer 7

Attachment sites

Question 8

What is the humerus?

Answer 8

A long bone found in the arm

Question 9

What does the proximal humerus have?

Answer 9

2 necks, 2 tubercles and an intertubercular sulcus (bicipital groove)

Question 10

What does the intertubercular sulcus have?

Answer 10

A medial lip, a lateral lip and a floor

Question 11

What are intrinsic ligaments?

Answer 11

Thickenings of the joint capsule

Question 12

What are extrinsic ligaments?

Answer 12

Provide support to a joint but are located some distance away from the joint capsule

Question 13

What type of joint is the sternoclavicular joint?

Answer 13

Structurally, classified as a saddle joint

Functionally, acts like a ball and socket joint

Question 14

What are the ligaments of the sternoclavicular joint?

Answer 14

intrinsic:
- anterior sternoclavicular ligament
- posterior sternoclavicular ligament
Extrinsic
- interclavicular ligament
- costoclavicular ligament

Question 15

What moves during abduction of the arm?

Answer 15

The clavicle elevates to an angle of around 60 degrees

Question 16

What moves during the protraction and retraction of the scapula?

Answer 16

The lateral end of the clavicle swings anteriorly and posteriorly

Question 17

What moves during flexion of the arm?

Answer 17

The clavicle rotates on its own longitudinal axis

Question 18

Does the sternoclavicular joint dislocate?

Answer 18

It’s so strong that it rarely dislocates

Instead, the clavicle is a commonly fractured bone

Question 19

What joint is the acromioclavicular joint?

Answer 19

A plane joint

Question 20

What are the ligaments of the acromioclavicular joint?

Answer 20

Intrinsic ligament:
- acromioclavicular ligament
Extrinsic ligaments:
- Coracoclavicular ligament
     - conoid ligament
     - trapezoid ligament

Question 21

What is the dislocation of the AC joint known as?

Answer 21

Shoulder separation

Question 22

What joint is the glenohumeral joint?

Answer 22

Ball and socket

Question 23

What is the glenoid cavity deepened by?

Answer 23

the glenoid labrum (lip)

Question 24

_____ passes through the capsule to each the ______.

Answer 24

Tendon of long head of biceps brachii passes through the capcule to reach the supraglenoid tubercle

Question 25

What assists in maintaining shoulder joint stability?

Answer 25

Rotator cuff muscles

Question 26

What allows for full abduction of the arm?

Answer 26

Inferior aspect of the joint capsule is loose and weak

Question 27

What are the ligaments of the glenohumeral joint?

Answer 27

Intrinsic:
- Glenohumeral ligament (superior, middle, inferior)
- Coracohumeral ligament
- transverse humeral ligament
Extrinsic:
- coracoacromial ligament

Question 28

What forms the coracoacromial arch?

Answer 28

Coracoid process
Coracoacromial ligament
Acromion

Question 29

What is the dislocation of the glenohumeral joint known as ?

Answer 29

Shoulder dislocation

Question 30

What joint is the scapulothoracic joint?

Answer 30

Physiological joint (not real)

Question 31

What does movement of the scapula allow?

Answer 31

movement of the humerus in extreme flexion and abduction

Question 32

For every 3 degrees of rotation, __ degrees comes from ________ and __ degrees comes from _______.

Answer 32

2 degrees comes from glenohumeral joint

1 degree comes from scapulothoracic joint