230 OLIVE OILS AND HEALTH - alveolar bone The alveolar bone is the portion of the maxillary bones (upper maxilla and mandible) that forms and supports the tooth sockets (alveoli), in which the roots of the teeth are anchored. - bone resorption Bones support body weight, external loads, and sudden movements, such as jumping. Fortunately, they are continuously renewed throughout life through a process known as bone remodelling. In this process, old bone is broken down by the action of osteoclasts, releasing minerals from the bone matrix into the bloodstream. At the same time, osteoblasts are responsible for forming new bone tissue. Although other factors are involved, osteoclasts and osteoblasts are the key players in this process. Bone remodelling is regulated by hormones (such as parathyroid hormone, calcitonin, vitamin D, growth hormone), and proteins acting as growth factors produced in the bone marrow. This regulation allows the body to maintain a balanced rate of bone formation and resorption, in line with its physiological needs. Bone resorption is therefore a normal and necessary process that also plays a role in repairing damaged bone (as osteoclasts remove damaged tissue to be replaced by healthy bone through the activity of osteoblasts), and in regulating mineral metabolism, especially calcium. This helps maintain appropriate blood calcium levels, which are essential for many bodily functions, such as muscle contraction. - deoxypyridinoline Pyridinoline and deoxypyridinoline are non-reducible cross-linking amino acids that stabilise mature collagen fibres in human bone and cartilage. They are found within the extracellular matrix of these tissues. These compounds are clinically useful as markers of bone resorption and are employed in the monitoring of postmenopausal women undergoing oestrogen therapy. - diaphyseal It refers to the tubular (or shaft) portion of a long bone located between its two ends, known as epiphyses. - metaphyseal It refers to the metaphysis, the part of a long bone located between the diaphysis (shaft) and each epiphysis (located at both ends of the bone). The metaphysis plays a crucial role during childhood and adolescence, as it contains the growth plate (epiphyseal cartilage), a layer of cartilage whose cells divide and progressively transform into bone at the upper and lower edges. This process causes the diaphysis to lengthen, the epiphyses to move apart, and the individual to grow in height. During puberty, an increase in hormone levels accelerates this process, leading to a point where bone formation exceeds cartilage generation, until the cartilage is fully replaced by bone. At that stage, longitudinal growth stops and bones can only grow in thickness. The metaphysis then becomes simply a transitional zone between the epiphysis and the diaphysis. structure of a long bone Epiphysis Metaphysis Diaphysis Metaphysis Epiphysis
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