Week 4: Tuesday, Sept 19th_Short answer

The two main components of bone composition are the extracellular matrix and the cells.

The two types of bone marrow are red and yellow bone marrow.

Cortical bone makes up 75-80% of the skeletal mass, while trabecular bone makes up 20-25%.

Physical activity level and nutrient intake (Protein, Ca2+, VitD, Mg2+)

Physical inactivity, smoking, high alcohol intake, inadequate nutrient intake

Sex-hormone decline, decreased production of sex hormones, decreased insulin-like growth factor and growth hormone, increased cytokines, decreased VitD and Ca2+ absorption, impaired osteoblast production from osteogenic stem cells, decreased ability for cells to sense and respond to mechanical forces

Abnormal curvature of the spine, height decrease, fragility/spontaneous fracture, back pain from compression fractures in the spine

Age, Genetics, Inflammation, Overuse / Disuse, Overweight: increased mechanical loading stress, Obesity: pro-inflammatory state

Pain with movement and weight bearing, Swelling, Limited ROM (stiffness), Crepitus may be heard, Deformity

Articular cartilage: Structural damage and erosion due to mechanical stress, inflammation, Proteolytic enzymes are released from chondrocytes which further degrades cartilage, Bone becomes exposed and damaged (cracks form), Cysts and osteophytes develop, Pieces of osteophytes and damaged cartilage break off and float around in synovial cavity, Degeneration of articular cartilage leads to friction, damage, inflammation, and pain

Low impact exercise, Flexibility, Strength, Aerobic, Emphasize importance of muscle strengthening exercises, 3 x per week is ideal for experiencing quick effective pain relief, Analgesic benefits seen in just a few weeks, even in >75YO