KINESIOL 3U03 Lecture Notes - Lecture 3: Dual-Energy X-Ray Absorptiometry, Myocyte, Myogenesis
12 May 2016
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Document Summary
Focus will be on skeletal muscle: very difficult to do in children because they are invasive, less invasive mri in canada, not many and always full. Fetal stage small fibres, not many and separated by ecm. At birth fibres still small, increased in number and packed a little more closely. Adult larger diameter fibres and more tightly packed: alterations in chemical composition occurs overtime (chart in slide. With growth : decrease in extracellular ions (na and cl, increase in intracellular components (k and p, % water decreases, extracellular component decreases as fibre number and size increase. Total muscle nitrogen increases from prenatal to adulthood. Fibrillar protein increases because of physical demand and anabolic hormones. Extracellular protein % increases to max at birth and decreases as we get older (as muscle fibres get bigger, there is less space for extracellular material: can be noted on body composition assessment. Pluripotent cells myoblasts myotubes mature muscle.
