Structural and Functional Classifications

Question 1

Define Arthroses/articulations/joints

Answer 1

• an articulation is the place where 2 elements of the skeleton meet (bone, cartilage, teeth)

Question 2

List the 3 functions of articulations

Answer 2

1. transmit forces
2. enable or restrict movement
3. accommodate growth

Question 3

List the 4 types of articulation

Answer 3

1. Bony
2. Fibrous
3. Cartilaginous
4. Synovial

Question 4

Describe BONY articulations

Answer 4

• bone is connected to bone by bone
• no movement
• called synostosis
• epiphyseal line: remnant after epiphyseal growth plate closure

Question 5

Describe FIBROUS articulations

Answer 5

• connected by dense regular connective tissue proper
• no or minimal movement
  e. g.
• suture = no movement
• syndesmosis = interosseous membranes, inferior tibiofibular joint= some movement
• gomphosis = tooth in alveolar socket = no movement

Question 6

Describe CARTILAGE articulations

Answer 6

• connected by cartilage
  e. g.
  1. Hyaline cartilage: synchondrosis, no movement (epiphyseal plate, costochondral joints)
  2. Fibrocartilage: pad between hyaline cartilage covered bones, some movement (intervertebral disc joints, pubic symphysis)

Question 7

Describe SYNOVIAL articulations

Answer 7

• space between the bones

- designed for mobility

Question 8

Describe the 4 features of synovial joints

Answer 8

1. Joint cavity
2. Contact is between the articular cartilage covering bones
3. Double layered articular capsule
   - Outer layer: fibrous (DICTP)
   - Inner layer: synovial membrane
4. Viscous synovial fluid

Question 9

Describe what the amount and direction of movement is determined by in synovial joints

Answer 9

• shape of the articular surfaces

- associated joint structures

Question 10

List the 7 structures of synovial joints

Answer 10

1. Plane/gliding
2. Hinge
3. Pivot
4. Bicondylar
5. Ellipsoid (e.g. condylar)
6. Saddle
7. Ball and socket

Question 11

Describe Plane/gliding joints in more detail

Answer 11

• flat articular surfaces
• uniaxial
  e. g. intercarpal joints, intertarsal joints

Question 12

Describe Hinge joints in more detail

Answer 12

• 1 convex and 1 concave articulating surfaces
• uniaxial
  e. g. humeroulna joint, interphalangeal joint

Question 13

Describe Pivot joint in more detail

Answer 13

• bont pivot in an osteolligamentous ring
• bone rotates around longitudinal axis
• uniaxial
  e. g. median atlanto-axial joints, proximal radio ulna joint

Question 14

Describe Bicondylar joint in more detail

Answer 14

• 2 convex condyles articulate with concave or flat surfaces
• predominantly uniaxial
  e. g. tibiofemoral joints, atlanto-occipital joints

Question 15

Describe ellipsoid joints in more detail

Answer 15

• 1 oval convex and 1 oval concave articulating surface
• biaxial
  e. g. metacarpophalangeal (MCP), radoiocarpal joint (RCJ)

Question 16

Describe Saddle joints in more detail

Answer 16

• 2 concavo-convex surfaces
• biaxial
  e. g. 1st carpometacarpal joint

Question 17

Describe Ball and socket joints in more detail

Answer 17

• spherical head articulates with a cup-shaped socket
• multiaxial
  e. g. coxal (hip) joints, glenohumeral joint

Question 18

Define synarthroses, amphiarthroses and diarthroses

Answer 18

Synarthroses: no movement
Amphiarthroses: limited movement
Diarthroses: freely mobile