What Is The Differences between Osteoblast and Osteoclast?

So, what is the main difference between osteoblast and osteoclast? The former is responsible for the formation of bones and the latter for the breakdown of bones. 

Osteoblast and osteoclast are crucial types of bone cells that consist of bone tissues or osseous tissues. These types of bone cells play an essential role during metabolic activities. The coordination of action between these two bone cells helps in the formation and breakdown of bones. According to science, bone remodeling is the coordination action of osteoblast and osteoclast.

The bone remodeling process helps to enhance bone maintenance and regulation of vital minerals. Calcium and phosphorus are among the most important minerals for the bones.  This article provides a comprehensive explanation of the differences between osteoblast and osteoclast.  Take the time to read through it and also get to know their similarities. 

Subscribe To My Channel, Please

Differences between Osteoblast and Osteoclast (With Table)

Basic Terms




Bone cells responsible for bone formation.

Bone cells responsible for the breakdown of bones.

Cell Size

Comparatively smaller.

Comparatively larger.

Cell Type



Cell Organelles

Relatively lesser number.

Relatively larger number.


Make protein-osteoid.

Do not make protein osteoid.

Cells Appearance

Cells do not possess sealing zones and ruffled borders.

Cells possess sealing zones and ruffled borders.

Hormones Produced


No hormone produced.

Parathyroid Hormone Receptors



Cell Production

Produce a large amount of alkaline phosphatase enzyme.

Produce a large amount of tartrate-resistant acid phosphatase enzyme.

Derived from

Pluripotent mesenchymal stem cells.

Hematopoietic cells of the granulocyte

Phagocytic-like Mechanism



End Result

Osteoblasts become osteocytes at the end of the bone formation.

Osteoclasts do not become osteocytes.


Formation and mineralization of bones

Bone breakdown and bone resorption

What is Osteoblast?

Osteoblasts are specialized cells crucial to the process of bone formation and maintenance within the skeletal system. These cells are responsible for synthesizing and secreting the organic components of the bone matrix, including collagen and various proteins. As bone-forming cells, osteoblasts play a pivotal role in the initial stages of bone development, contributing to the creation of new bone tissue.

Once osteoblasts deposit the organic matrix, minerals such as calcium and phosphate adhere to it, leading to the mineralization of the bone. This process results in the formation of a dense and durable structure that provides support and strength to the skeletal framework.

Osteoblasts are typically found on the surfaces of developing or repairing bone, and their activity is tightly regulated by various signaling pathways and hormones. As bone-forming cells, osteoblasts work in conjunction with other cell types, such as osteocytes, to maintain the delicate balance of bone remodeling.

While osteoblasts are critical for bone formation, their counterpart, osteoclasts, plays a vital role in bone resorption. The dynamic interplay between osteoblasts and osteoclasts ensures the continuous renewal and adaptation of bone tissue to meet the mechanical and metabolic demands placed on the skeletal system throughout an individual’s life.

In summary, osteoblasts are specialized cells responsible for the synthesis and deposition of the organic components of the bone matrix, contributing significantly to bone formation and the maintenance of skeletal integrity.

What is Osteoclast?

Osteoclasts are specialized cells that play a crucial role in the dynamic process of bone remodeling within the skeletal system. Unlike osteoblasts, which are involved in bone formation, osteoclasts are bone-resorbing cells responsible for breaking down and resorbing existing bone tissue.

Osteoclasts possess a unique ability to secrete enzymes and acids, creating an acidic microenvironment that dissolves the mineralized matrix of bone. This enzymatic activity, particularly involving acid secretion and the release of proteolytic enzymes, allows osteoclasts to break down the inorganic and organic components of bone, such as calcium and collagen, respectively. This process releases minerals back into the bloodstream, contributing to calcium homeostasis in the body.

The activity of osteoclasts is tightly regulated by various signaling pathways, hormones, and interactions with other cells, including osteoblasts. The balance between the bone-forming activity of osteoblasts and the bone-resorbing activity of osteoclasts is essential for maintaining skeletal health and structural integrity. An imbalance in this process can lead to conditions such as osteoporosis, where bone resorption exceeds bone formation.

Osteoclasts are typically found on bone surfaces and create small cavities or pits known as Howship’s lacunae during the resorption process. Their role in bone remodeling is essential for repairing microdamage, adapting bone to mechanical stresses, and maintaining overall bone density.

In summary, osteoclasts are specialized cells vital for the breakdown and resorption of bone tissue, contributing to the continuous remodeling and adaptation of the skeletal system throughout an individual’s life.

Main Differences Between Osteoblast and Osteoclast

  1. The osteoblast entails the formation and mineralization of bones while the osteoclast involves bone breakdown and resorption.
  2. Osteoblasts are single cells that operate in groups while osteoclasts are multinucleated cells that comprise about 200 nuclei per cell.
  3. Osteoblasts are formed from the osteogenic cells whereas osteoclasts are developed from bone marrow, macrophages, and monocytes.
  4. Osteoblasts are derived from the mesenchymal osteoprogenitor cells that promote the bone remodeling process while osteoclasts are derived from hematopoietic cells responsible for bone resorption.
  5. Osteoclast cells are comparatively larger when compared to osteoblast cells.
  6. Osteoclast cells have a larger amount of organelles such as mitochondria, vacuoles, and lysosomes as compared to osteoblast.
  7. Osteoblast cells tend to make protein osteoid while osteoclast cells do make any proteins.
  8. Osteoblast cells contain a large amount of alkaline and phosphatase enzyme while osteoclast contains acid, tartrate-resistant, and phosphatase enzyme.
  9. Osteoclast cells are equipped with the phagocytic-like mechanism while osteoblast cells are not equipped.
  10. The end result of osteoblast cell is osteocytes while osteoclast does not have any end result.

 Similarities Between Osteoblast and Osteoclast

  1. Both are bone cells
  2. Both get involved in the bone remodeling process
  3. Both promote bone repair
  4. Both the cells have a nucleus
  5. Both are connective tissues
  6. Both are found in the bone
  7. Both are metabolically active cells

Frequently Asked Question

  • How Do Osteoblasts Differ from Osteoclasts?

Osteoblasts are large cells that dissolve in the bone and they are mainly found on the surface of the bone next to the dissolving one. Osteoclasts are bones that form new bones. They are found in the bone marrow and are related to structural cells. 

  • What Type of Cells Divides and Differentiate into Osteoblast or Osteoclast?

Osteogenic cells. They are bone cells that divide and differentiate to form new bones. They secrete a collagen matrix and calcium salts. 

  • What Stimulates Osteoblast Activity?

Parathyroid hormone. It is a protein made by the parathyroid gland under the control of serum calcium activity.

  • What are the Two Types of Bone Cells?

The main types of bone cells are osteoblastsosteoclastsosteocytes, and osteoprogenitors. They are unique in function and they are found in different parts of the body. 

  • What Activates Osteoblasts?

Primary murine osteoblasts and the osteoblast cell line MC3T3 will be activated with osteotropic agents (LPS, PTH, IL-1, etc.) or antibodies to specific cell surface determinants.

You May Also Like:


Osteoblasts and osteoclasts are two distinct types of cells involved in the dynamic process of bone remodeling. Osteoblasts and osteoclasts play complementary roles in maintaining bone structure and density.

Osteoblasts are bone-forming cells responsible for the synthesis and secretion of the bone matrix, which includes collagen and other proteins. They actively participate in bone mineralization, helping to build and repair bone tissue. Osteoblasts are essential during the early stages of bone formation and contribute to the production of new bone.

In contrast, osteoclasts are bone-resorbing cells responsible for breaking down and resorbing bone tissue. They secrete enzymes and acids that dissolve the mineralized matrix and break down the organic components, releasing minerals like calcium back into the bloodstream. Osteoclasts play a crucial role in bone remodeling by removing damaged or old bone and maintaining calcium homeostasis in the body.

The balance between osteoblast and osteoclast activity is vital for maintaining healthy bone density and structure. Imbalances in this process can lead to conditions such as osteoporosis, where bone resorption exceeds bone formation.

In summary, osteoblasts and osteoclasts are integral to the dynamic process of bone remodeling. Osteoblasts contribute to bone formation by synthesizing and depositing new bone matrix, while osteoclasts are involved in the breakdown and resorption of bone tissue. The coordinated activity of these cells is crucial for maintaining skeletal health and functionality.

More Sources and References

  1. Cell Types in Bones. Biology LibreText

  2. Osteoblast. Wikipedia 

  3. Osteocyte. Britannica 

Leave a Comment