10. Principles of Articulation

Question 1

Structural classification of joints

Answer 1

Presence or absence of a synovial cavity and the type of connective tissue.

• fibrous
• cartilaginous
• synovial

Question 2

Functional classification of joints

Answer 2

Based on the degree of movement permitted

• Synarthrosis (immovable)
• Amphiarthrosis (partially moveable)
• Diarthrosis (freely moveable)

Question 3

Fibrous joints (3 types)

Answer 3

• No synovial cavity
• Held together by a fibrous connective tissue
• Permits little or no movement (synarthrosis/amphiarthrosis)

Three types of fibrous joint:

• Suture
• Syndesmosis
• Interosseous membrane

Question 4

What is a suture joint?

Answer 4

Type of fibrous joint between sutures

Thin layer of dense connective tissue

Irregular shape–interlocks–Synarthrosis

• Ossification of a suture forms a synostosis
  e. g. left and right sides of frontal bone fuse ~6 years of age

Question 5

What is a syndesmosis joint?

Answer 5

Type of fibrous joint

More connective tissue than suture joint

Connective tissue arranged in bundles

Amphiarthosis (slight movement)

Question 6

Cartilaginous joints

What are the 2 types of cartilaginous joint?

Answer 6

• Non-synovial
• Held together by a fibrocartilage or hyaline cartilage
• Permits little or no movement (synarthrosis/amphiarthrosis)
• Synchrondosis
• Symphysis

Question 7

Synchrondosis cartiliaginous joints

Answer 7

• The connective tissue is hyaline cartilage
• Synarthrosis
• Example: epiphyseal plate (growth plate)

Question 8

Symphysis cartiliaginous joints

Answer 8

• Connective tissue is fibrocartilage

- Amphiarthrosis

Question 9

Glenohumeral joint

Answer 9

Synovial ball and socket joint

between the proximal humerus and the scapula (glenoid fossa

most mobile joint due to shallow glenoid cavity

glenoid labrum- deepens glenoid

stabilised by

• glenohumeral
• coracohumeral
• transverse humeral

Question 10

Name the 4 rotator cuff muscles

Answer 10

supraspinatus
infraspinatus
teres minor
subscapularis

Question 11

Acromioclavicular joint

Answer 11

-Synovial planar joint that acts like a pivot

Stabilised by three ligaments:

• acromioclavicular
• coracoacromial
• coracolclavicular (conoid and trapezoid)

-Allows the movement of the scapula, permitting greater arm rotation (above the head)

Question 12

Sternoclavicular joint

Answer 12

Synovial saddle joint

Fibrocartilagenous articular disc divides the joint into two synovial cavities

Reinforced by interclavicular, anterior, and posterior sternoclavicular ligaments

Triaxial movement