Joints

Question 1

Name components of a joint?

Answer 1

• Bone
• Fat; packing+insulating.
• Fibrous tissue; collagen fibres.
• Ligaments; join bone to bone.
• Tendons; attach muscle to bone.
• Cartilage; cells+fibres organised for strength, elasticity.
• Hyaline cartilage; at articular surfaces, absorb shock.
• Fibrocartilage; within vertebral discs,less elasticity.

Question 2

What is a joint?

Answer 2

• A joint is where 2 or more articulating bones meet.
• 3 main categories;
• —- Fibrous
• —- Cartilaginous
• —- Synovial

Question 3

Describe fibrous joints?

Answer 3

• Bone surfaces held by dense fibrous tissue.
• Minimal movement.
• Sutures = small gaps between bones.
• Syndesmoses = bones joined by tissue called an interosseous ligament.
• Gomphosis = binds teeth to sockets with ligament.

Question 4

Describe cartilaginous joints?

Answer 4

• Articulating bone surfaces held by cartilage.

- Limited movement, more than fibrous, not much movement in individual joints.

Question 5

Describe synovial joints?

Answer 5

• Movable joints!!
• Ends of long bone, within articular capsules, lined with a synovial membrane which secretes synovial fluid (lubricates joint).
• Nerves and vessels supply.
• Intracapsular; tendons, ligaments, fat.
• Cartilage = cushion joint.
• Fat pads = protect articular cartilages.
• Ligaments = support + strengthen joint.
• Tendons attach to muscles around joint.
• Bursae = pockets of synovial fluid, cushion areas.

Question 6

Name all the function movements in the joints?

Answer 6

• Flexion + extension
• Abduction + adduction
• Circumduction
• Plantarflexion + dorsiflexion
• Lateral + Medial rotation
• Lateral flexion
• Supination + Pronation
• Elevation + Depression
• Retraction + Protraction
• Inversion + Eversion

Question 7

Describe uniaxial synovial joints?

Answer 7

• Movement through one plane.
• Hinge joints = flexion + extension (elbow).
• Pivot joints = rotation only.
• Gliding joints = small gliding movements (carpal bones)

Question 8

Describe biaxial synovial joints?

Answer 8

• Movement through 2 planes.
• Ellipsoid joints = flexion + extension and abduction + adduction (MCP’s).
• Saddles joints = Flex+exte, abd+add (CMC in thumb)

Question 9

Describe the multiaxial synovial joints?

Answer 9

• Movement through three planes.
• Ball and socket joints =
  
  • F+E, A+A, MR+LR, C.
  • Joint cannot be mobile and strong, weak but good mobility.

Question 10

How to describe a joint?

Answer 10

• Type of joint
• Articular surfaces
• Ligaments
• Functions
• Movement within it