What are the 4 main cells of bone tissue?
Bone is composed of four different cell types; osteoblasts, osteocytes, osteoclasts and bone lining cells. Osteoblasts, bone lining cells and osteoclasts are present on bone surfaces and are derived from local mesenchymal cells called progenitor cells.
What are the 4 main cells of bone tissue and what do they do?
The osteoblast, osteoclast, osteocyte, and osteoprogenitor bone cells are responsible for the growing, shaping, and maintenance of bones.
What are the 4 structures of bone?
Bones consist of different types of tissue, including compact bone, spongy bone, bone marrow, and periosteum. All of these tissue types are shown in Figure below. Compact bone makes up the dense outer layer of bone. Its functional unit is the osteon.
What are osteoblasts osteoclasts and osteocytes?
Osteoblasts are bone-forming cell, osteoclasts resorb or break down bone, and osteocytes are mature bone cells. An equilibrium between osteoblasts and osteoclasts maintains bone tissue.
What are the 5 bone cells?
Bone tissue consists of five major cell types: Bone lining cells, osteoblasts, osteocytes, osteoclasts and osteogenic cells.
What are types of bone tissue?
There are 3 types of bone tissue, including the following:
- Compact tissue. The harder, outer tissue of bones.
- Cancellous tissue. The sponge-like tissue inside bones.
- Subchondral tissue. The smooth tissue at the ends of bones, which is covered with another type of tissue called cartilage.
What are osteoclast cells?
Osteoclasts are the cells that degrade bone to initiate normal bone remodeling and mediate bone loss in pathologic conditions by increasing their resorptive activity. They are derived from precursors in the myeloid/monocyte lineage that circulate in the blood after their formation in the bone marrow.
What is a bone cell called?
Bone tissue is maintained by bone-forming cells called osteoblasts and cells that break down bone called osteoclasts. Bones also contain blood vessels, nerves, proteins, vitamins, and minerals. Also called osseous tissue.
What does an osteocyte look like?
A mature osteocyte is defined as a cell surrounded by mineralized bone, and is described as a stellate or star-shaped cell with a large number of slender, cytoplasmic processes radiating in all directions, but generally perpendicular to the bone surface.
What do osteocytes look like?
Osteocytes have a stellate shape, approximately 7 micrometers deep and wide by 15 micrometers in length. The cell body varies in size from 5-20 micrometers in diameter and contain 40-60 cell processes per cell, with a cell to cell distance between 20-30 micrometers.
What are osteoblast cells?
Osteoblasts are specialized mesenchymal cells that synthesize bone matrix and coordinate the mineralization of the skeleton. These cells work in harmony with osteoclasts, which resorb bone, in a continuous cycle that occurs throughout life.
What do osteoblasts look like?
Superficially, osteoblasts appear similar to plasma cells, but they are larger and have less-condensed nuclear chromatin. Osteoblast nuclei are round to oval in shape, have reticular chromatin, and may have one or two nucleoli.
What do osteoclasts look like?
In bone, osteoclasts are found in pits in the bone surface which are called resorption bays, or Howship’s lacunae. Osteoclasts are characterized by a cytoplasm with a homogeneous, “foamy” appearance. This appearance is due to a high concentration of vesicles and vacuoles.