Itt írjon a(z) BloodGlucoseBone-ról/ről
The effect of blood glucose on bone health
Glucose is the foundation of energy for most organisms on the planet. It makes sense that glucose will have an effect on normal bone development because it is the most essential energy biomolecule for organisms capable of respiration. As we know, bones have a powerful role in blood formation. Hence, bones will have a large capillary network for nutrients and products to leave/enter. Glucose’s main mode of transport is indeed the blood so the bones will have direct contact with fresh blood with glucose present. Our results concluded that diseases, such as diabetes mellitus, can cause fluctuation in blood glucose levels and hence bone health. Type 1 diabetes highlighted a result of lower bone mineral density (BMD) leading to a higher risk of osteoporosis. Whereas, type 2 diabetes causes increased BMD. However, the increased calcification is irregular and similarly to type 1, bone fractures were also a considerably high risk. This study revealed evidence to prove blood glucose has a role in bone metabolism.
Contents
==1 - Introduction == The skeleton is often seen as an inert entity. However, old bone fragments are broken down and replaced with new skeleton tissue continuously. In fact, the skeleton replaces itself within ten years. New studies reveal a close connection between bone cells and blood glucose levels. This assignment aims to investigate bone health and how the effects of differing blood glucose levels can change the make-up of bones in the body.
2 - Normal Bone Development
During the early stages of embryonic development, the embryo’s skeleton consists of hyaline cartilage and a fibrous membrane. By the seventh week of embryonic life, the process of bone development, ossification (osteogenesis) starts. There are two different osteogenic pathways, intramembranous ossification and endochondral ossification. Bone is the same, regardless of what pathway produces it.
a.''Cartilage Templates''
Bone is a replaceable tissue, it uses a model tissue to lay down its mineral matrix. For skeletal development the most common template is cartilage. During foetal development a structure is laid down that determines where the bones will eventually form. This structure is a semi-solid matrix which is flexible and produced by chondroblasts, it contains water, collagen fibres, hyaluronic acid and chondroitin sulphate. Cartilage is avascular, therefore it does not have blood vessels that can supply nutrients and remove any waste product. These functions are carried out through diffusion through the matrix. This is why damaged cartilage does not repair itself as easily as other tissues. Through foetal and childhood growth and development, bone will form on this cartilaginous matrix. When the foetus is born the majority of the cartilage will be replaced with bone. The additional cartilage will be replaced with bone throughout childhood development and some remnants of cartilage will remain. The two stages of bone development through foetal development is Intramembranous ossification and Endochondral ossification. The four general categories of bones are long bones, short bones, flat bones, and irregular bones. Long bones include the clavicles, humeri, radii, ulnae, metacarpals, femurs, tibiae, fibulae, metatarsals, and phalanges. Short bones include the carpal and tarsal bones, patellae, and sesamoid bones. Flat bones include the skull, mandible, scapulae, sternum, and ribs. Irregular bones include the vertebrae, sacrum, coccyx, and hyoid bone. Flat bones form by membranous bone formation, whereas long bones are formed by a combination of endochondral and membranous bone formation. (Clarke, B., 2008.) Bone undergoes longitudinal and radial growth, modelling, and remodelling during life. Longitudinal and radial growth during growth and development occurs during childhood and adolescence. Longitudinal growth occurs at the growth plates, where cartilage proliferates in the epiphyseal and metaphyseal areas of long bones, before subsequently undergoing mineralization to form primary new bone. (Clarke, B., 2008.)
b.''Endochondral ossification''
Endochondral ossification is the type of bone ossification where bone tissue is created directly over the cartilage.
