Bone Remodelling

Question 1

Healthy bone tissue

Answer 1

Bone formation (osteoblastogenesis) is coupled with bone resorption (osteoclastogenesis)

Question 2

What is bone remodelling influenced by

Answer 2

Growth, mechanical stresses, hormonal - calcium homeostasis, immunological

Question 3

What are the diseases characterised by

Answer 3

Unbalanced osteoclastogenic activity

Question 4

What are osteoclasts

Answer 4

Large multi-nucleate cells of phagocytic lineage

Question 5

Parathyroid hormone

Answer 5

Stimulates osteoclastogenesis to release calcium in times of need.

Question 6

Precursor

Answer 6

Hormone calcitriol is the active form of vitamin D made in kidney. Required for taking up calcium from diet

Question 7

Inflammatory diseases affect

Answer 7

Disrupt balance of bone formation and bone resorption leading to increased osteoclastogenesis = increased bone loss

Question 8

Periodontitis

Answer 8

Destructive Inflammatory disease. Loss of periodontal ligament and alveolar bone. Chronic immune response to oral bacteria (bystander damage). Chemicals in inflammatory tissues cause monocytes to fuse and differentiate into osteoclasts. Uncoupling of bone remodelling

Question 9

Types of arthritis

Answer 9

Joints bathed in synovial fluid.
Osteoarthritis - initially affects smooth cartilage in joint, cartilage lining roughens and thins out meaning tendons and ligaments work much harder. Bone on bone
Rheumatoid arthritis - autoimmune disease. Pain and swelling. Synovial affected then further swelling. Monocytes differentiate into osteoclasts

Question 10

Rickets in children

Answer 10

Osteomalacia

Question 11

Describe osteomalacia

Answer 11

Failure of osteoid to mineralise adequately due to lack of vitamin c/calcium/phosphate. Bones are weakened and can cause enamel hypoplasia and delayed tooth eruption

Question 12

What material covers 95 percent of the enamel

Answer 12

Hydroxyapatite