Lecture 4 - Bones and Joints of the Pectoral Girdle

Question 1

TRUE OR FALSE:

Pectoral girdle is part of the axial skeleton

Answer 1

FALSE

Pectoral girdle is part of the appendicular skeleton

Question 2

What does the pectoral girdle refer to

Answer 2

scapula and clavicle

Question 3

Describe the shape of the clavicle

Answer 3

S-shaped bone

Question 4

The clavicle connects what parts of the body

Answer 4

connects the upper limb to the trunk

Question 5

The medial half of the clavicle is _____ anteriorly and the lateral half of the clavicle is _____ anteriorly

Answer 5

medial half: convex anteriorly

lateral half: concave anteriorly

Question 6

List the articulations for the clavicle

Answer 6

medially: articulates with the manubrium of the sternum
laterally: articulates with the acromion of the scapula

Question 7

How is the superior surface different from the inferior surface in the clavicle

Answer 7

superior surface: smooth

inferior surface: rough due to bone markings from ligaments and muscles

Question 8

Describe the shape of the scapula

Answer 8

triangular shaped bone

Question 9

where is the scapula located

Answer 9

posterior to the rib cage

Question 10

_____ articulates with the head of the humerus

Answer 10

glenoid fossa/cavity

Question 11

What does “fossa” mean?

Answer 11

shallow depression

Question 12

Where does the head of the humerus articulate?

Answer 12

articulates with the glenoid fossa of the scapula

Question 13

What are the landmarks of the proximal humerus?

Answer 13

• 2 necks
• 2 tubercles
• 1 intertubercular sulcus (bicipital groove)

Question 14

What are the different part of the bicipital sulcus?

Answer 14

• lateral lip
• floor
• medial lip

Question 15

What are intrinsic ligaments?

Answer 15

thickenings of portions of the joint capsule

Question 16

What are extrinsic ligaments?

Answer 16

• located some distance away from the joint

- provide support to a joint

Question 17

What is the sternoclavicular joint?

Answer 17

Where the sternal end of the clavicle articulates with the manubrium of the sternum

Question 18

The SC joint is classified as what type of joint?

Answer 18

structurally: saddle joint
functionally: ball and socket joint (more mobile)

Question 19

What are the ligaments of the SC joint?

Answer 19

intrinsic ligaments:

• anterior SC ligament
• posterior SC ligament

extrinsic ligaments:

• Costoclavicular ligament
• interclavicular ligament

Question 20

What is within the joint capsule of the SC joint?

Answer 20

articular disc

Question 21

TRUE OR FALSE:

The SC joint is very strong but not very mobile

Answer 21

FALSE:

The SC joint is both very strong and very mobile

Question 22

What happens to the clavicle during abduction of the arm?

Answer 22

elevates to 60 degrees

Question 23

What happens to the clavicle when the scapula is protracted and retracted?

Answer 23

the lateral ends of the clavicle swings anteriorly and posteriorly

Question 24

What happens to the clavicle during arm flexion?

Answer 24

rotates on its own longitudinal axis

Question 25

What is the acromioclavicular joint? (AC joint)

Answer 25

when the acromial end of the clavicle articulates with the acromion of the scapula

Question 26

The AC joint is classified as what type of joint?

Answer 26

plane joint

Question 27

TRUE OR FALSE:

Both the SC and AC joint are likely to dislocate in an accident

Answer 27

FALSE:

The AC joint is much more likely to dislocate; shoulder seperation

Question 28

Name the ligaments of the AC joint

Answer 28

Intrinsic ligament:
- AC ligament

Extrinsic ligament:
- coracoclavicular ligament (conoid ligament and trapezoid ligament)

Question 29

How can the AC joint get dislocated?

Answer 29

by falling on an outstretched upper limb or by a direct blow to the shoulder

Question 30

What is the glenohumeral joint?

Answer 30

The head of the humerus articulates with the glenoid fossa of the scapula

Question 31

What type of joint does the glenohumeral joint classify as?

Answer 31

ball and socket (synovial) joint

Question 32

What causes the glenoid cavity to be deepened?

Answer 32

the glenoid labrum

Question 33

What passes through the capsule of the glenohumeral joint?

Answer 33

the tendon of the long head of biceps brachii passes through the capsule to reach the supraglenoid tubercle

Question 34

What muscles assist in maintaining shoulder joint stability?

Answer 34

rotator cuff muscles

Question 35

What does the weak and loose aspect of the inferior aspect of the glenohumeral joint allow for?

Answer 35

full abduction of the arm

Question 36

What are the ligaments of the glenohumeral joint?

Answer 36

intrinsic ligaments:

• glenohumeral ligaments (superior, middle, inferior)
• coracohumeral ligament
• transverse humeral ligament

extrinsic ligament:
coracoacromial ligament

Question 37

What forms the coracoacromial arch?

Answer 37

coracoid process, coracoacromial ligament, acromion

Question 38

What is the glenohumeral dislocation usually refered to as?

Answer 38

shoulder dislocation

Question 39

Where do dislocations tend to happen in the glenohumeral joint?

Answer 39

inferiorly as the superior aspect is protected by the coracoacromial arch

Question 40

TRUE OR FALSE:

The scapula has no direct attachment to the rib cage

Answer 40

TRUE

Question 41

What is the scapulothoracic joint described as?

Answer 41

physiological joint (function, not structure)

Question 42

What does the movement of the scapula permit in terms of the the humerus?

Answer 42

allows for movement of the humerus in extreme flexion and abduction

Question 43

true or false:

for every 3 degrees of rotation, 2 degrees come from the scapulothoracic joint and 1 deg comes from the glenohumeral joint

Answer 43

FALSE:

2 deg from glenohumeral joint
1 deg from scapulothoracic joint