It is easy and. inexpensive to test for coliform bacteria. If testing detects coliform bacteria in a water sample, water systems search for the source of contamination and restore safe drinking water.
The osteon, or Haversian system, is the fundamental functional unit of much compact bone. Osteons, roughly cylindrical structures that are typically several millimeters long and around 0.2 mm in diameter. Each osteon consists of concentric layers, or lamellae, of compact bone tissue that surround a central canal, the Haversian canal. The Haversian canal contains the boneâs nerve and blood supplies. Osteoblasts form the lamellae sequentially, from the most external inward toward the Haversian canal.
2.2 The Structure of Spongy Bone Spongy Bone does not include osteons (the basic unit/s of Compact Bone-see above). Instead, spongy bone consists of an irregular lattice of thin columns of bone called trabeculae (literally little beams), which contain lamellae, osteocytes, lacunae and canaliculi.he basic unit of Compact Bone is an  osteon , which is also known as a  Haversian System . Each Haversian System (unit) has a cylindrical structure that consists of four parts: 1  A central tube called a Haversian Canal, which contains blood vessels and nerves. 2  The Haversian Canal is surrounded by alternate layers of: