Bones & Joints

1. Bones & Joints Access Human Biology. Clare Hargreaves-Norris

2. Introduction • Bones are connected to each other by connective tissue. • A joint is where two or more bones meet together. • Without joints the skeleton would not be able to move or have very limited movement. Clare Hargreaves-Norris

3. Cancellous (spongy) bone. Clare Hargreaves-Norris

4. Types of Joints. • There are three main types of joints. • Immovable joints (fibrous or fixed): Fibrous connective tissue is used for immovable joints such is the cranium (sutures). • Semi-movable joints (cartilaginous or slightly movable): Cartilage is used for semi-moveable joints such as the vertebrae. • Synovial joints are the most common types of joints. • Synovial joints are freely moveable joints that are held together by ligaments. Clare Hargreaves-Norris

5. Synovial joints • Synovial joints have a fibrous capsule that is lined with the synovial membrane. • The synovial membrane secretes synovial fluid. • Synovial fluid; • Lubricates the joint. • Provides nutrients to joint. • Helps to maintain stability of joint. • Helps to keep ends of bones in line. • Articular cartilage coats the ends of the bones to protect against wear and tear by reducing friction at the joint. • Extra ligaments may surround the outside of the joint to provide extra strength and some also contain discs of cartilage to maintain stability. • The main support to the joints is provided by muscles. Clare Hargreaves-Norris

6. Synovial Joints. • Synovial joints are subdivided according to movements possible. Clare Hargreaves-Norris

7. Clare Hargreaves-Norris

8. The Three Planes of Movement. • Flexion (forwards and backwards). • Extension (straightening). • Abduction (away from body). • Adduction (towards the body). • Rotation (around). • Circumduction (combination). Clare Hargreaves-Norris

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13. Clare Hargreaves-Norris