Bone Cells

What are the four types of bone cell and their primary functions?

• Osteogenic cells: Unspecialized stem cells that give rise to osteoblasts.

• Osteoblasts: Bone-building cells

• Osteocytes: Mature bone cells

• Osteoclasts: Bone-resorbing cells that break down bone

How do osteoblasts function in bone formation?

Osteoblasts secrete bone matrix, trapping themselves in lacunae (spaces) where they become osteocytes. They also take calcium from the blood to form bone.

Osteoblasts are stimulated by

Stimulated by: Calcitonin, estrogen, and other hormones.

What is the role of osteocytes in bone maintenance?

Osteocytes are mature bone cells that maintain bone tissue by:

• Stimulating the formation of new bone or the break down of existing bone.

• Communicating with other osteocytes through long extensions (canaliculi).

What is the role of osteoclasts in bone resorption?

Osteoclasts break down bone tissue (bone resorption) to release calcium into the blood, increasing blood calcium levels.

Stimulated by: Parathyroid hormone (PTH).

What are osteoclasts stimulated by

Stimulated by: Parathyroid hormone (PTH).

What is the relationship between osteoblasts and osteoclasts?

Osteoblasts and osteoclasts have an antagonistic relationship:

• Osteoblasts build bone.

• Osteoclasts break down bone.

Which hormones regulate osteoblasts and osteoclasts, and what are their effects?

• Calcitonin: Stimulates osteoblast activity (bone building).

• Parathyroid hormone (PTH): Stimulates osteoclast activity (bone resorption).

These hormones have an antagonistic relationship in regulating bone metabolism.