BIOS251 WK 6 CASE STUDY
Introduction Recap:
Osteoporosis is intricately connected to disruptions in normal bone physiology. Understanding
the pathophysiology of osteoporosis requires examining the delicate balance of bone
remodeling, a dynamic process governed by bone-forming osteoblasts and bone-resorbing
osteoclasts.
Normal Bone Physiology:
 Bone Remodeling:
o Osteoblasts: are specialized cells responsible for bone formation. They produce
and mineralize the bone matrix, synthesizing collagen and other proteins.
o Osteoclasts: are multinucleated cells that break down bone tissue through
resorption, releasing minerals back into the bloodstream.
 Osteocytes:“mature” bone cells: When osteoblasts become surrounded by matrix, they
are referred to as OSTEOCYTES. These guys were osteoblasts but had trapped
themselves in the matrix they had created. Osteocytes are mature osteoblasts that
become trapped in the bone matrix.
 Bone matrix: The bone matrix is a dynamic structure composed of organic components,
primarily collagen, and inorganic minerals such as calcium and phosphate. This matrix
provides strength, flexibility, and support to the skeletal system.
 Bone Density Maintenance: Homeostasis is maintained through a delicate balance
between bone formation and resorption, ensuring proper bone density and strength.
Osteoporosis Discussion:
 Osteoporosis is a metabolic disease characterized by bone demineralization, with loss of
calcium and phosphorus salts leading to fragile bones and the subsequent risk for
fractures. Osteoporosis is marked by loss of trabecular and cortical bone mass which
leads to bone weakness and increased susceptibility to fractures. Bone resorption
accelerates as bone formation slows. Osteoporosis occurs most commonly in the wrist,
hip, and vertebral column. Osteoporosis is the most common type of bone disease
affecting many older Americans. Osteoporosis occurs because of an imbalance in the
bone remodeling process. Bone resorption by osteoclasts is favored over bone
formation by -osteoblasts, resulting in loss of bone mass. The etiology of osteoporosis
results from an imbalance in the activity of osteoblasts and osteoclasts. More
specifically, reduced osteoblastic activity or increased osteoclastic activity leads to a net
loss of bone mass.