Osteon

You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.

Osteon
Transverse section of body of human fibula, decalcified. X 250.
Gray's	subject #18 89
Dorlands/Elsevier	o_08/12601039

Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [1] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.

Overview

Osteons (also called Haversian system in honor of Clopton Havers) are predominant structures found in some lamellar or compact bone. Osteons are found in many of the bones of many mammals, birds, reptiles, and amphibians running in a meandering way but generally parallel to the long axis of bones. It is this section of compact bone that is called matrix.

In the center of the osteon is a central canal, called the Haversian canal.

The central canal is surrounded by concentric layers of matrix called lamellae. These lamellae are laid down one after the other over time, each successive one inside the preceding one. Collagen fibers in a lamella run parallel to each other but the orientation of collagen fibers across separate lamellae is oblique. The fiber density is also lower at the border between adjacent lamellae, which accounts for the distinctive appearance of an osteon.

Osteocytes are found between concentric lamellae and connected to each other and the central canal by cytoplasmic processes through the canals called canaliculi. This network permits the exchange of nutrients and metabolic waste.

Osteons are separated from each other by cement lines. Collagen fibers and canaliculi do not cross cement lines.

The space between separate osteons is occupied by interstitial lamellae, which were formed by pre-existing osteons that have since been reabsorbed.

Osteons are connected to each other and the periosteum by oblique channels called Volkmann's canals.

Use in archaeology and forensics

Osteons carry their history so that given the right conditions they can be used to "read" the sex, age, health history, motor history and apparently something of the diet of an individual's bone. Osteons and their arrangement also vary according to taxon, so that genus and sometimes species can be differentiated using a bone fragment not otherwise identifiable. This is of use in archaeology, paleontology and forensics.

See also

• Haversian canals

Literature

• Martiniaková, Monika 2006 Differences in Bone Microstructure of Mammalian Skeletons. Faculty of Natural Sciences, Constantine the Philosopher University in Nitra: Nitra, Slovakia.
• Pfeiffer, Susan; Crowder, Christian; Harrington, Lesley; and Brown, Brown 2006 "Secondary Osteon and Haversian Canal Dimensions as Behavioral Indicators," American Journal of Physical Anthropology, 131 (4): 460 - 468.
• Cooper, Reginald R.; Milgram, James W.; and Robinson, Robert A. 1966 "Morphology of the Osteon: An Electron Microscopic Study," Journal of Bone and Joint Surgery, 48:1239-1271.

External links

• SLIBS Bone Website: http://www.trinity.edu/rblyston/bone/intro2.htm
• MeSH Haversian+System
• Bioweb at UWLAX Bone model

v • d • e Musculoskeletal system, connective tissue: bone and cartilage
Cartilage	perichondrium, fibrocartilage callus, metaphysis cells (chondroblast, chondrocyte) types (hyaline, elastic, fibrous)
Bone	ossification (intramembranous, endochondral, epiphyseal plate) cycle (osteoblast, osteoid, osteocyte, osteoclast) types (cancellous, cortical) regions (epiphysis, metaphysis, diaphysis) structure (osteon/Haversian system, Haversian canals, Volkmann's canals, endosteum, periosteum, Sharpey's fibres, enthesis, lacunae, canaliculi, trabeculae, medullary cavity, bone marrow) shapes (long, short, flat, irregular, sesamoid)

de:Osteon

WikiDoc Help Menu Quick Start.. Get Started Here! How to Login How to Search Pages How to Start a New Page How to Edit a Page Cheat Sheet Editing basics Learning Basic Formatting How to make Links in WikiDoc & to External Sites How to Make Lists How to Ignoring Formatting Adding References or Footnotes to Articles Tracking Changes You Have Made How to Put an Article Into a Category When Multiple Topics Should Go To The Same Page (MI, Acute MI, AMI) Using Redirection Advanced editing How to Make Tables How to Insert Images and Other Media How to Add Video Help:How to Make Columns Web Colors How To Make Templates How to Move Pages Inserting Dynamic Dates and Times Inserting WikiDoc Statistics Editing the Table of Contents Communicating your edits Let others know what you changed: The importance of Edit Summaries Minor Edits Edit Conflicts Help Videos You Can Watch Getting Started Video

Acknowledgement and Attribution Regarding Sources of Content

Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .