Search results
Results from the WOW.Com Content Network
The cell body varies in size from 5–20 micrometers in diameter and contain 40–60 cell processes per cell, [4] with a cell to cell distance between 20–30 micrometers. [3] A mature osteocyte contains a single nucleus that is located toward the vascular side and has one or two nucleoli and a membrane. [ 5 ]
In osteology, the osteon or haversian system (/ h ə ˈ v ɜːr. ʒ ən /; named for Clopton Havers) is the fundamental functional unit of much compact bone. Osteons are roughly cylindrical structures that are typically between 0.25 mm and 0.35 mm in diameter . [ 1 ]
The radiating processes of the osteocytes (called filopodia) project into these canals. These cytoplasmic processes are joined together by gap junctions. Osteocytes do not entirely fill up the canaliculi. The remaining space is known as the periosteocytic space, which is filled with periosteocytic fluid. This fluid contains substances too large ...
Osteoblasts are mononucleate bone-forming cells. They are located on the surface of osteon seams and make a protein mixture known as osteoid, which mineralizes to become bone. [23] The osteoid seam is a narrow region of a newly formed organic matrix, not yet mineralized, located on the surface of a bone. Osteoid is primarily composed of Type I ...
In an ordinary microscopic section, viewed by transmitted light, they appear as fusiform opaque spots. Each lacuna is occupied during life by a branched cell, termed an osteocyte, bone-cell or bone-corpuscle. Lacunae are connected to one another by small canals called canaliculi. A lacuna never contains more than one osteocyte.
However, in the process of bone formation, osteoblasts function in groups of connected cells. Individual cells cannot make bone. A group of organized osteoblasts together with the bone made by a unit of cells is usually called the osteon. Osteoblasts are specialized, terminally differentiated products of mesenchymal stem cells. [1]
In developing bones, ossification commences within the primary ossification center located in the center of the diaphysis (bone shaft), [5] where the following changes occur: The perichondrium surrounding the cartilage model transforms into the periosteum. During this transformation, special cells within the perichondrium switch gears.
Osteoblasts are cells that group together to form units, called osteons, to produce bone. Runx2 (which may also be known as Cbfa1), and Osx (a zinc finger containing transcription factor) are necessary for osteochondroprogenitor cells to differentiate into the osteoblast cell lineage.