Joints

Question 1

What are the three types of joint classification?

Answer 1

Synarthroses - Immovable (serves to protect vital organs e.g the joints between the bones of the skull)

Amphiarthroses - Slightly movable ( e.g Invertebral discs

Diarthroses - Freely movable (Either uniaxial, biaxial or multiaxial)

Question 2

What are the three structural classifications of joints?

Answer 2

1. Fibrous: Dense Connective Tissue
2. Cartilaginous Joints
3. Synovial Joints

Question 3

What are the types of fibrous (dense CT) joints?

Answer 3

a) Sutures; fibrous joints that permits no movement
eg. skull sutures
b) Gomphosis; fibrous joint where peg fits in socket and is held in place by a fibrous bond or ligament
eg. roots of teeth
c) Syndesmosis; fibrous joint united by a larger amount of fibrous tissue, by a ligament or an interosseus membrane
eg. interosseus membrane btw radius and ulna

Question 4

What is a cartilaginous joint and what are the two types?

Answer 4

A joint entirely joined by cartilage, either fibrocartilage or hyaline cartilage.

a) Synchondroses - bones united by a single layer of hyaline cartilage

b) Symphysis - articulating surfaces of bones are covered in hyaline cartilage but also have a pad of fibrocartilage between them. This allows for small, controlled movement
eg. between vertebrae

Question 5

What is a synovial joint?

Answer 5

• A synovial joint is a freely moveable joint surrounded by a joint capsule. Movement is only limited by the joint capsule and ligaments or muscles crossing the joint
• Articular hyaline cartilage covers the articular surfaces of the bones (it is hard and smooth and minimizes friction)
• Fibrous joint capsule is lined by a synovial membrane that secretes synovial fluid into the joint cavity
• Fluid nourishes and lubricates the articular cartilage