What type of bone cell breakes down and what event causes them to form more bones?

Osteoclasts are the bone cells that break down bone tissue. This process is known as bone resorption. Osteoclasts are activated when the body needs calcium and phosphorus, or when old or damaged bone tissue needs to be replaced.

Osteoblasts are bone cells that help the bone to grow and repair itself. They do this by building new bone tissue and laying down collagen fibres. When osteoblasts are activated, they form a structure known as an osteon, which is a cylinder-shaped unit of bone tissue.

The balance between bone resorption and bone formation is essential for maintaining healthy bones. When the balance is disrupted, it can lead to bone diseases such as osteoporosis, which is characterised by weak and brittle bones.