MEDS 7/2 - Joints

1. Recognise and apply anatomical terminology relating to joints. 2. Define a joint. 3. Classify a joint as fibrous, cartilaginous, or synovial. 4. Identify key features of different joint classifications including key structural feature and range of motion available. 5. Assess clinical implications of joint pathologies (e.g. rheumatoid arthritis, disc degeneration).

What is an articulation?

There is an articulation between two bones

What are joints?

An articulation between two or more bones.

What are the functions of joints?

• Movement

• Mechanical support

• Binding

What are the three classifications for joints?

• Fibrous

• Cartilaginous

• Synovial

What are the composition and mobility of fibrous joints?

• Made up of dense fibrous connective tissue.

• Little to no movement

What are (3) examples of fibrous joints?

• Skull sutures

• Interosseous membranes

• Inferior tibiofibular joint

What are the composition and mobility of cartilaginous joints?

• Cartilage - hyaline or fibrocartilage.

• Slightly movable

What are the two classifications of cartilaginous joints?

• Primary - synchondrosis

• Secondary - symphasis

What are Synchondrosis (Primary) Cartilaginous joints?

• Made up of hyaline cartilage

• No movement

• Eg epiphyseal growth plates.

What are Symphasis (Secondary) Cartilaginous joints?

• Made up of hyaline cartilage over bone with a fibrocartilage plate in between.

• Assist force transmission/shock absorption

• Eg. Intervertebral disc

What makes up a Synovial joint (5)?

• Joint capsule

• Synovial membrane

• Joint cavity

• Articular cartilage

• Synovial fluid

What else may be found in a Synovial joint (4)?

• Bursa

• Fat pads

• Ligaments

• Articular discs

What is the mobility (+ example) of a synovial joint?

• Move freely

• Knee joint

What is the role of Articular Cartilage (hyaline) in synovial joints?

• Minimise friction during mobility

What is the role of Joint Capsules (fibrous) in synovial joints?

Attaches the joints together.

What is the role of Ligaments in synovial joints?

Strengthens Joint Capsule

What is the role of the Synovial Membrane in synovial joints?

Produces synovial fluid.

What is the role of Synovial Fluid in synovial joints?

Lubricate and nourish cartilage.

What is the role of an Articular Disc in a synovial joint?

Improves how well joints fit together and shock absorption.

What is the role of Fat Pads in synovial joints?

Fill spaces

What are the 3 classifications of Synovial Joints?

• Uniaxial

• Biaxial

• Multiaxial

What are Uniaxial Synovial Joints?

• Movement in one plane

• Hinge joint - flexion/extension

• pivot joint - rotation

What are examples of Uniaxial Synovial Joints?

• Elbow joint (hinge)

• Proximal Radioulnar joint (pivot)

What are Biaxial Joints?

• Movement in two planes

• Condyloid and Saddle

How do Condyloid Biaxial joints move + example?

• flexion/extension + abduction/adduction

• Wrist

How do Saddle Biaxial joints move + example?

• flexion/extension + abduction/adduction + opposition

• Thumb

What are Multiaxial Joints?

• Movement in more than 2 planes

• Ball and socket joints

• Plane joints

How do Ball and Socket Multiaxial joints move + example?

• flexion/extension + abduction/adduction + internal/external rotation

• Shoulder joint

How do Plane Multiaxial joints move + example?

• Gliding movements - no distinguished direction

• Intercarpal joints

What is craniosynostosis?

• When the gaps between the skull bones (fontanelles) fuse before they are supposed to in babies.

• The brain begins to push out in the other areas and the head becomes deformed.

What causes scoliosis?

Degeneration of the spinal discs leads to unequal loading on one side and then curvatures.

What is Rheumatoid Arthritis?

Inflammation of the synovial joint which causes friction, damage to bone, limited movement and pain.

What is Osteoarthritis?

Disease of the bone and the whole joint.