Haversian System http://webs.ashlandctc.org/mflath/KEY%20SKELETAL%20I%20OBJECTIVES.htm

Clopton Harvers Born in 1655 in England Studied at Cambridge Both a Physician and an Anatomist Practiced medicine in London for most of his life Credited for his in-depth studies of the bones that ultimately led to the discovery of the 'Haversian canals' in them Died in 1702

What exactly is a Harversian System? Compact bone contains many cylinder-shaped structural units called osteons (Haversian systems) Each osteon runs lengthwise through the bone These Haversian systems makeup the structural framework of compact bone The unique composition of the osteons allows for the delivery of nutrients and the removal of certain waste products produced from metabolically active bone cells

Composition of the Haversian System Four types of structures make up each osteon (haversian system) 1. Lamellae 2. Lacunae 3. Canaliculi 4. Haversian Canal

Lamellae (la-MEL-ay) Concentric, cylinder-shaped layers of calcified matrix http://faculty.une.edu/com/abell/histo/Histolab4e.htm

Lacunae (la-KYOO-nay) Latin for “little lakes” Small spaces containing tissue fluid in which bone cells lie imprisoned between the hard layers of the lamellae http://faculty.une.edu/com/abell/histo/Histolab4e.htm

Canaliculi (CAN-uh-LIK-you-lye) Very tiny canals radiating in all directions from the lacunae and connecting them to each other and into the Haversian canal http://faculty.une.edu/com/abell/histo/Histolab4e.htm

Haversian Canal Extends lengthwise through the center of each osteon Contains blood vessels, lymphatic vessels, and nerves from the Haversian canal Nutrients and oxygen move through canalculi to the lacunae and their bone cells Each Haversian canal is connected by tansverse Volkmann’s canals (contain nerves and vessels that carry blood and lymph to the osteons) http://newscenter.lbl.gov/feature-stories/2008/08/06/the-toughness-of-bone/