Systole heart beats—is cued by messages from the brain, reflecting the brain's responses to conditions of the body, such as pain, emotional stress, level of activity, and to ambient conditions including external temperature, time of day, etc. Electrical systole opens voltage-gated sodium, potassium and calcium channels in cells of myocardium tissue. Subsequently, a rise in intracellular calcium triggers the interaction of actin and myosin in the presence of ATP which generates mechanical force in the cells in the form of muscular contraction, or mechanical systole. The contractions generate intra-ventricular pressure, which is increased until it exceeds the external, residual pressures in
Adipose tissue more easily than a person of the same weight with more muscular tissue, since muscular tissue has a density of 1.06 g/ml. A body fat meter is a widely available tool used to measure the percentage of fat in the human body. Different meters use various methods to determine the body fat to weight ratio. They tend to under-read body fat percentage. In contrast with clinical tools, one relatively inexpensive type of body fat meter uses the principle of bioelectrical impedance analysis (BIA) in order to determine an individual's body fat percentage. To achieve this, the meter passes a small,