Long+Bone

(Image courtesy of: [|http://www.web-books.com/eLibrary/Medicine/Physiology/Skeletal/long_bone.jpg)]

Bones provide protection, support and shape, and movement to the body. Bones protect the body’s vital organs from outside pressure and blows. Bones offer support to the body as well as gives the body its shape. Movement occurs because bones provide levers for muscles and ligaments to act upon. Long bones provide all these things as well as make up the majority of a persons height. Long bones are longer than they are wide. Long bones grow in length as a result of the epiphysis pushing away from the diaphysis during endochondral ossification at the epiphyseal plate. This process forms new bone tissue and pushes the epiphysis away from the diaphysis. Appositional growth also occurs on long bones. Appositional growth results in a growth of thickness rather than length. Long bones have a two epiphysis ends, a diaphysis shaft, a medullary cavity, and bone marrow within. A layer of periosteum covers the outer layer of compact bone. Endosteum covers the inside of the medullary cavity. Long bones consist of spongy bone as well as compact bone. However, compact bone forms the majority of long bones. Long bones are found throughout the body. Limbs of the body usually are comprised of long bones. The long bones of the body include the femurs, tibias, fibulas, humeri, radii, ulnas, and the phalanges of the toes and fingers.

(Image courtesy of [|http://www.anatomyatlases.org/MicroscopicAnatomy/Images/Plate45.jpg)] FETAL[| LONG BONE] =__The Fractures and breaks of the long bone__:= The most common type of ailment for long bones are when they break, or fracture. Closed fractures are those in which the skin is intact, while open (compound) fractures involve wounds that communicate with the fracture and may expose bone to contamination. Open injuries carry an elevated risk of [|infection]; they require [|antibiotic] treatment and usually urgent surgical treatment (debridement). This involves removal of all dirt, contamination, and dead tissue. These factors if left untreated or ignored can create harsh consequences, such as permenant bone damage, infection by foeign material or debri in the open wound, and severe to mild amounts of blood loss, the bone will heal itself but the blood produceing capabilities of the red marrow will be restricted. =__Bone Dieases__:= Osteoporosis is a common disease of old age, which results in a decrease in the amount of bone in the skeleton, as well as a deterioration in the bone structure. These changes result in a weakening of the skeleton, leading to an increased chance of breaking a bone; a fracture. The most common sites of fracture are the bones of the spine, the hip and the wrist. However other bones are commonly affected, including the shoulder (proximal humerus), ribs and the pelvis. Osteoporosis is most common in women after menopause but elderly men are also commonly affected. [|Osteomalacia] is the adult counterpart of rickets in children. Both of these conditions are caused by a defect in vitamin D availability or metabolism. Osteomalacia is characterised by poor bone formation, resulting in weakened bone. Paget's disease, otherwise known as osteitis deformans, is a chronic disorder that typically results in enlarged and deformed bones. It is named after [|Sir James Paget], the British surgeon who first described this disease. The excessive breakdown and formation of bone tissue that occurs with Paget's disease can cause bone to weaken, resulting in bone pain, arthritis, deformities, and fractures. Paget's disease may be caused by a slow virus infection, present for many years before symptoms appear. There is also a hereditary factor since the disease may appear in more than one family member. These only acount for 3 of the many dozens of other bone diseases.