Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Msk > The Shoulder Joint > Flashcards

The Shoulder Joint Flashcards

1
Q

Describe the shoulder joint

A 
Shoulder Joint (Gleno humeral joint)
Synovial joint
Ball & socket  type
Most mobile joint:  Wide range of movements in multiple planes
Least stable: most commonly dislocated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are he articular surfaces of the shoulder joint

A

Glenoid fossa - in the living state the glenohumeral fossa would be covered with articular cartilage

and head of humerus - also covered with articular cartilage

There is a 4:1 disproportion in area of articular surfaces (had bigger) - glenoid cavity deepened by glenoid fossa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why is the glenohumeral joint unstable?

A 
SJ  inherently unstable
– Glenoid fossa shallow
– Disproportion of articular surfaces
– Multiplanar movements
– Lax capsule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is the glenohumeral joint made more stable?

A 
Stability is achieved by
– Muscles of the rotator cuff  (most important)
– Other muscles
– Ligaments
– Capsule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the capsule

A 
Capsule
Attached to
– Glenoid labrum & margins of glenoid fossa
– anatomical neck of humerus
– dips down medially to surgical neck
(laxity for full abduction) 
– bridges intertubular groove
Tough but lax to allow movement
Small opening anteriorly
– synovial membrane of SJ communicates with subscapular bursa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the role of synovial membrane?

A

Synovial Membrane
Lines:
1. Capsule
2. Intra capsular bone, up to edge of articular cartilage
3. Tendon of long head of the biceps within joint cavity
The tendon acquires a tubular sleeve of synovium as it enters joint, which surrounds it up to its insertion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the intra capsular ligaments

A

Intra capsular Ligaments
• 3 Gleno-humeral ligaments (superior, middle, inferior)
• 3 fibrous bands
• extend from glenoid labrum to humerus
• Part of the fibrous capsule
• Reinforces capsule anteriorly
• Can only be seen from inside the capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the extracapsular ligaments?

A
  1. Coracoacromial ligament (CAL)
    Between Acromion & coracoid process (important – more later)
  2. Coracohumeral ligament
    From base of coracoid process to anterior part of greater tubercle
  3. Transverse humeral ligament
    holds the tendon of long head of biceps in place during shoulder movement)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the coraco acromial arch?

A

Formed by Coracoacromial ligament + Acromion + Coracoid process
– a strong structure of bone & ligament (osseoligamentous structure )
– overlies the humeral head;
– prevents upper displacement of humerus
– Clinically important in the `painful arc’ syndrome (more later)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the rotator cuff

A 
A collective name given to 4 short muscles closely associated with the joint The most important factor giving stability to the joint
1. Supraspinatus, 
2. Infraspinatus, 
3. Teres minor 
4. Subscapularis 
mnemonic = ‘sits’
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where to the rotator cuff muscles arise and insert?

A

3 arise on dorsal aspect of Scapula
Supraspinatus
Infraspinatus
Teres minor
All 3 muscles inserted into Greater tubercle of humerus
Supraspinatus tendon passes under Coraco-acromial arch
Teres minor arises from ?? Inserts at?

1 from ventral aspect of Scapula
Subscapularis
Subscapularis muscle inserted into lesser tubercle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the role of the rotator cuff muscles?

A

Rotator Cuff Muscles
• The tendons blend to form a cuff
• Cuff fuses with capsule and strengthens it
• Tone in the muscles holds the head close to glenoid cavity
• Supraspinatus tendon is separated from Coraco acromial arch (CAA) by the bursa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the actions of the rotator cuff muscles?

A

ACT to stabilise the Shoulder joint, holding the head of the humerus in the glenoid cavity.

Also:
Supraspinatus – initiation & first 150 of abduction.
n – suprascapular C5,6

Infraspinatus – lateral (external) rotation of the arm
n – suprascapular C5,6

Teres Minor – lateral rotation of the arm weak adductor
n – axillary C5,6

Subscapularis - medial (internal) rotation of the arm
n – upper & lower subscapular nerves C5,6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What other muscles stabilise the shoulder joint?

A 
Other muscles stabilising SJ
1. Deltoid
2. Long head of biceps
(attached to Supra glenoid tubercle)
3. Long head of triceps
(attached to Infra glenoid tubercle)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the static and dynamics stability of the shoulder joint provided by?

A
  1. Tendons of the rotator cuff (Dynamic) (anteriorly, posteriorly, superiorly)
  2. Coraco acromial arch (superiorly)
  3. Gleno -humeral (Intra capsular) ligaments (anteriorly, inferiorly) 4. Coraco-humeral ligament (superiorly)
  4. Deepening glenoid cavity by labrum (circumferentially) 6. Splinting effect of: the long head of the biceps (Dynamic) (superiorly) & the long head of the triceps (Dynamic) (inferiorly)
  5. Other muscles (Dynamic) – Deltoid (anteriorly, posteriorly, superiorly) Pectoralis major (anteriorly), Coracobrachialis (anteriorly)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the subacromial bursa?

A

Facilitates movement of supraspinatus tendon under the Coraco acromial arch & Deltoid

17
Q

What is the subscapular bursa?

A
  • Facilitates movement of subscapularis tendon over scapula

* communicates with the joint cavity

18
Q

What is in the space between the acrimony and head of the humerus

A

Space between acromion & head of humerus about 1- 1.5cm
Interposed in this space are the:
1. Subacromial Bursa
2. Supraspinatus tendon
3. Capsule
4. Tendon of Long head of Biceps
During abduction, risk of soft tissue impingement between Head of humerus & Acromion

19
Q

Describe the blood supply to the shoulder joint

A
  • Anterior circumflex humeral artery
  • posterior circumflex humeral artery
  • Suprascapular artery
20
Q

Describe the nerve supply to the shoulder joint

A

Nerve supply:
•Axillary nerve
•Suprascapular
•Lateral Pectoral nerves from the brachial plexus (C5,6);

21
Q

Where do the movements of the shoulder joint occur?

A

Occur at Glenohumeral joint & Scapulothoracic joint. (Scapula moves over thorax as if there was a joint)

22
Q

Describe the abduction of the shoulder joint

A

First 900 abduction - Glenohumeral joint
• 00 – 150 Supraspinatus - suprascapular nerve
• 15- 900 Deltoid (central fibres) – axillary nerve
Above 900 By rotation of scapula at Scapulothoracic joint
Trapezius (upper fibres) & Serratus anterior

23
Q

What is the role of the trapezius

A

Trapezius – n Accessory nerve
• Superior fibres of trapezius rotate scapula upwards on chest wall
Attached to spinous processes and nuchal ligament

24
Q

What is the role of the serrated anterior?

A

Serratus anterior n - long thoracic nerve
• protracts and stabilises scapula
on chest wall;
• assists in upward rotation

25
Q

What extends the shoulder joint?

A

Extension of the shoulder joint

• Posterior fibres of Deltoid
n-Axillary nerve

• Latissimus dorsi
n-thoraco dorsal nerve

• Teres major
n- Lower subscapular

26
Q

What flexes the shoulder joint?

A

Flexion of the shoulder joint

  1. Clavicular head of Pectoralis major – (medial & lateral pectoral nerves)
  2. Anterior fibres of Deltoid – (axillary nerve)
  3. Coracobrachialis - (musculocutaneous nerve)
  4. Biceps brachii - (musculocutaneous nerve)
27
Q

What adducts the shoulder joint?

A

Adduction of the shoulder joint
• Pectoralis major (medial & lateral pectoral nerves)
• Latissimus dorsi (long thoracic nerve)
• Teres major (lower subscapular)

28
Q

What internally rotates the shoulder joint?

A

Internal (Medial) rotation

  1. Sternal head of pectoralis major (n –Medial & Lateral Pectoral nerves)
  2. Subscapularis (n- upper and lower subscapular nerves)
  3. Teres major (n - lower subscapular)
  4. Latissimus dorsi (n – Thoraco dorsal)
29
Q

What externally rotates the shoulder joint?

A

Lateral (external) rotation

• Infraspinatus (n – suprascapular) • Teres minor (n-axillary)

Msk (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions