2- physiology of joints

Question 1

what are 3 types of joints?

Answer 1

1. synovial
2. fibrous
3. cartilaginous

Question 2

what produces and reabsorbs synovial fluid?

Answer 2

synovial cells (fibroblasts) in synovial membrane

Question 3

what are articular surfaces of bone covered with in synovial joints?

Answer 3

articular cartilage

Question 4

what are the 2 classifications of synovial joints?

Answer 4

1. simple = 1 pair of articular surfaces
2. compound = more than 1 pair of articular surfaces like elbow

Question 5

what are some extra articular compounds of synovial joint?

Answer 5

ligament, tendon, bursae

Question 6

what is function of synovial fluid?

Answer 6

= to lubricate joint, reduce friction, minimise wear & tear , helps in nutrition of articular cartilage (cartilage avascular so nutrition & waste products removed etc with synovial fluid) so supplies chondrocytes with oxygen & nutrients and removes CO2 and waste

Question 7

what type of movement means synovial fluid less viscous and more elastic?

Answer 7

rapid movement (makes sense logically) - just get idea that synovial fluid varies a bit with movement and this can become defective in diseases

Question 8

what is normal appearance of synovial fluid? what does it look like if infection? or trauma?

Answer 8

synovial fluid = normally clear & colourless
inflammatory = gets more yellowy the more WBCs there are
turns red if traumatic synovial tap or haemorrhagic arthritis

Question 9

what are the zones of articular bone?

Answer 9

articular surface then superficial zone, middle zone, deep zone, calcified bone and then subchondral bone

Question 10

what makes up extracellular matrix of articular cartilage?

Answer 10

• made mostly of water (70%) and a bit of collagen, mainly type II (20%) and a bit of proteoglycans (10%)(less important →collagen provides stiffness&strength, proteoglycan provides compressive properties, water provides nutrition & lubrication)