Musculoskeletal Pathophysiology bones
2023-2024 A+
- Bone turnover
o 5-7% recycled weekly
o 0.5g enter/leave the adult skeleton each day
- deposition
... [Show More] organic matrix
- mineral resorption release of minerals blood
o osteoblasts: build bone hydroxyapatite crystals (calcium +phosphate)
o Osteoclasts: degrade (corrode) bone
- Calcium homeostasis: depends on a balance between dietary intake,
urinary andfecal losses, and exchanges between osseous bone tissue
o Regulated by 3 hormones: calcitriol, calcitonin, and parathyroid hormone
- Vitamin D is important for the absorption of calcium: produced by the
sequentialaction of the skin, liver, and kidneys. Behaves as a hormone
o Binds
newosteoclasts
Osteomalacia
Metabolic bone disease
o A deficiency of vitamin D lowers the absorption of calcium from the intestines
o Inadequate or delayed mineralization
o Bone formation progresses to the osteoid formation by calcification doesn’t occur
o Soft rather than rigid bone
o Symptoms are a pain when weight is put on the affected bone
▪ Also bone fractures, vertebral collapse, bone malformation
Rickets
Similar pathology to Osteomalacia but usually in children
o A bone-softening disease that causes severe bowing of the legs, and
deformities tothe pelvis, skull, and rib cage are common
o Poor growth and sometimes muscle pain and weakness
o Surgery often required
o The deformity can improve with the normalization of bone metabolism
- Exercise increases bone strength
Signs and symptoms of fractures
o Impaired function
o Unnatural alignment (deformity)
o Swelling
o Possible muscle spasm
o Tenderness and pain
o Bruising or discoloration around the break
o Impaired sensation
o X-ray evidence of a break
Fractures
o Open fracture: breakthrough intact skin, and bone marrow exposed to the
externalenvironment. Risk of infection and osteomyelitis
o Pathologic fracture: occurs in the bone that is weakened by
disease Egosteoporosis, bone metastasis, primary bone cancer
o Comminuted fracture: more than 2 parts of bone, harder to heal with
callusformation
o Impacted fracture: pressure/weight that causes the break. Impacts or
crushes therest of the bone
Callus formation.
- The bone is broken, causing
damage to surrounding tissue and
periosteum
□ bleeding due to
damage to blood
vessels inthecortex and
marrow. Formation
of hematoma
organized into the
fibrous network (bone
needs to be immobile
for thisto occur due to
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