American Academy of Professional Coders (AAPC) Practice Exam

What type of cell is responsible for bone formation?

1. Osteoclast

2. Osteoblast

3. Chondrocyte

4. Fibroblast

The correct answer is: Osteoblast

Osteoblasts are the specialized cells responsible for bone formation. These cells are essential in the process of ossification, where they synthesize and secrete the bone matrix, primarily composed of collagen and other proteins, which eventually mineralizes to form hard bone tissue. Osteoblasts are active during both the growth of bones in children and the remodeling process in adults, highlighting their crucial role in maintaining healthy skeletal structure and function. In contrast, osteoclasts have a different function related to bone health; they are involved in bone resorption, breaking down bone tissue, which aids in the process of remodeling and maintaining calcium homeostasis in the body. Chondrocytes are found in cartilage and are crucial for the development and maintenance of cartilage tissue, while fibroblasts primarily produce collagen and other fibers in connective tissue, rather than participating in bone formation. Thus, osteoblasts are the definitive answer to the question of which cells are responsible for bone formation.