composed of 1. cells (osteocytes) and 2. extracellular matrix (osteoid) that is impregnated with calcium phosphate salts.

a living structure where the metabolism of both 1. calcium and 2. phosphorus are extremely important

1. Achondroplasia

2. Osteogenesis imperfecta

3. osteopetrosis 

a defect in the production of Collagen 1

leads to thin fragile bones, thin skin, defective dental enamel and defective heart values 

marble bone disease

genetic defect in the osteoclasts, which does not allow them to remove bone matrix in remodeling.

bone becomes thick and brittle

no room for bone marrow and patient becomes ANEMIC.

successful treatment is marrow transplantation 

bones get blood supply from a Nutrient Artery and this is often the source of infection (hematogenous) 

bones are resistant to infections and if are infected, it is very difficult to treat

can be result of trauma, and a rare consequence of steroid medicine.

can occur in sickle cell disease and air emboli

absolute reduction in bone mass. can be divided in primary and secondary

bone losses structure and becomes soft and brittle

loss of organic bone matrix (osteoid) and minerals

may be multifactorial includes initial bone mass, diet and life style, hormones and age-related changes in metabolism 

affects women more than men

this is greatest in the vertebral bodies where crush fractures occur and the PaTient is shorter and bends foward

associated with hormonal disturbances, dietary insufficiency, immobilization and certain drugs

the long bones are involved with weakening of the neck of the femur 

lack of phosphorus, seen in hyperparathyroidism as the parathyroid hormone prevents reabsorption of phosphorous 

aluminum in anti-acids can bind to phosphorus 

when the kidney cannot excrete phosphorus, it rises and there is a compensatory decrease in calcium 

stimulates the parathyroid gland

osteitis deforman, irregular restructuring of bone where it becomes thickened. 

etiology not known and may effect skull and long bones

necessary for rapid reunion.

once the fracture heals, then rehabilitation exercises may be needed to complete return to normal 

1. hematoma then

2. influx of inflammatory cells and eventually granulation tissue then

3. bony formation (callus) then

4. remodeling 

rare and less than 1%

either benign or malignant

tumor on the cartilage called chondrosarcoma and a rare tumor call Ewing's sarcoma

often in young ages 

sarcomas in general metastasize via blood-lungs 

degenerative joint disease (DID), wear and tear with the articular cartilage to be primary site of injury

why young people get this as athletics get older

reason why gymnastics and tackle football should not be carried out by really young kids

very common when getting older especially in fingers

get new bony growth of the distal interphalangeal joints called herberden's nodules

anti-inflammatory drugs

examination of joint fluid not usually directly diagnostic 

chronic symmetric inflammation of joints

systemic disease with low-grade fever, anemia formation and rheumatoid nodules present in the skin, can develop fibrosis of lungs and pleural effusions and pericarditis

the neutrophils die and release enzymes that destory the joint and surrounding tissue. 

a disease of remissions and exacerbation, sort of like MS

can develop severe deformities of joints

in RA, we get this in the joint space

complement activated and neutrophils enter into the joint

typical organisms are Staphy and strep, GC, and TB

deposition of uric acid crystals, uric acid is end product of purine metabolism

classified as primary or secondary

uric acid crystals may be deposited in subcutaneous tissue, joints and kidney