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Bone Development

Submitted by asalamon on Fri, 09/20/2019 - 12:37

Why are humans, as a species vunderable to osteoporosis? Why are women even more susceptable to the illness?  These questions can be answered through evolutionary medicine.  Bones begin as cartilage with centers of ossification that allow for the growth of the bone over time.  Eventually, the centers for ossificaiton fuse and the bone stops growing.  Besides infancy, the fastest time for growth occures during adolesence.  The growth rate is direclty related to the amount of IGF released by the pititary gland of the individual.  During pubery for females, the bone density is rapidly being packed onto the bones.  Once puberty ends, females have a significalty higher bone density and mass than males.  This is important for reproduction as the calcium and nutrients of the bones is essential to pregancy and breastfeeding.  During menopause, women have a serious decrease in the amount of estrogen they produce. As a result there is a sudden drop in bone density.  As opposed to men who see a steady decrease in bone density over time, women see a sudden drop in bone density then continue to deterioate at a steady rate from there.  Because of the sudden drop during menopause, women are at a greater risk for osteoporosis than men.  This is an example of antagonistic pleiotrophy.  While levels of estrogen in women during puberty are essential to successful reproduce, they result in deterious consequences later in life.