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Diagram of a typical long bone showing both cortical (compact) and cancellous (spongy) bone. Haversian canals [i] (sometimes canals of Havers, osteonic canals or central canals) are a series of microscopic tubes in the outermost region of bone called cortical bone. They allow blood vessels and nerves to travel through them to supply the osteocytes.
All bones possess larger or smaller foramina (openings) for the entrance of blood-vessels; these are known as the nutrient foramina, and are particularly large in the shafts of the larger long bones, where they lead into a nutrient canal, which extends into the medullary cavity. The nutrient canal (foramen) is directed away from the growing end ...
The nutrient artery (arteria nutricia, or central artery), usually accompanied by one or two nutrient veins, enters the bone through the nutrient foramen, runs obliquely through the cortex, sends branches upward and downward to the bone marrow, which ramify in the endosteum–the vascular membrane lining the medullary cavity–and give twigs to the adjoining canals.
The Haversian canal contains the bone's blood supplies. The boundary of an osteon is the cement line. Each Haversian canal is surrounded by varying number (5-20) of concentrically arranged lamellae of bone matrix. Near the surface of the compact bone, the lamellae are arranged parallel to the surface; these are called circumferential lamellae.
They usually run at obtuse angles to the Haversian canals (which run the length of the bone) and contain anastomosing vessels between haversian capillaries. They were named after German physiologist Alfred Volkmann (1800–1878). The perforating canals, with the blood vessels, provide energy and nourishing elements for osteons.
The long bones of the human leg comprise nearly half of adult height. The other primary skeletal component of height are the vertebrae and skull. The outside of the bone consists of a layer of connective tissue called the periosteum. Additionally, the outer shell of the long bone is compact bone, then a deeper layer of cancellous bone (spongy ...
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A short bone is one that is cube-like in shape, being approximately equal in length, width, and thickness. The only short bones in the human skeleton are in the carpals of the wrists and the tarsals of the ankles. Short bones provide stability and support as well as some limited motion. [1]