What are the functions of pyrophosphate and how is it regulated
- It is a natural inhibitor of hydroxyapatite crystal formation
it is regulated by:
-Alkaline phosphate
-ANKH protein
-NPP1
Describe the process of bone mineralization.
- Osteoblasts release matrix vesicles that contain enzymes
- Enzymes in the vesicles hydrolaze phosphate containing compunds
- Then hydroxyapatite crystals grow and minealize
What are the hormones involbed in the process of bone mineralization
- Growth Hormones
-Parathyoid Horomone - Sex hormones
What is the role of calcium and vitamin D deficiency in the pathogenesis of osteoporosis
-Calcium is a major component of the bone
-Vitamin D helps the body absorb calcium
-deficiency leads ro decreased bone mineral density
What are the types of primary osteoporosis
- Type 1
- Type 2
What are the normal concentrations of calcium and phosphate
How are they regulated
Calcium- 8.5 -10.2
Phosphate- 2.5 - 4.5
- By Parathyroid hormone
How common is osteoporosis and who is at the highest risk
- Affects over 200 million people
- Women are at the highest risk due to lower estrogen levels
What tests are used to diagnose Osteoporosis
- Bone Mineral Density Test:
= DEXA
What is the Fracture Risk Assessment Tool
- A tool developed by the World health Organization
- To estimate an individuals 10 year probability of having major fractures
What causes secondary Osteoporosis
-It is caused by medical conditions that affect bone metabolism such as
What factors affect bone mass and bone strength
- Genetics
-Hormone levels
-Nutrition
-smoking and drinking
What is the role of Aging in the pathogenesis of Osteoporosis
- Bone remodelling slows down, leading to loss of bone mass and stength
What are stable and unstable vertebral fractures
- Stable vertebral fractures:
- Fractures that dont cause significant spinal deformity
Unstable vertebral fractures
- Fractures that can lead to spianl deformity
What is the most common type of Vertebral fracture
- Vertebral compression fracture
What are the most common locations of major osteoporotic fractires
Hip, spine and wrist fractures
What common spine curvature disorders are common in oatients with Oteoporosis
- Kyphosis: Outward curbature of the spine
- Lordosis:inward curvurture
Describe the process of ostroclast activation
- starts with RANKL and RANK interaction
- M-CSF( Macrophages colony stimulating factor ) which binds to receptors osteoclasts
- Activated osteoclasts create an acidic envirnment by releasing hydrogen ions
What is the pathogenesis (how it develops )of Osteoporosis
- By an imbalance between bone resorption and bone formation
What is the function of Osteoblast
- Bone forming cells
= SYnthesize and secret the bone matrix
What is the function of osteocytes
-Maintain bone tissue by regulating the mineral content
What are the functions of osteoclasts
-Responsible for bone resorption
