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
Sociology of the body such as anorexia and bulimia, and on the other end, there is a growing epidemic of obesity, especially in the US. Both ideals have increased widely over the last few decades due in part to growing mass media coverage in which there are norms within society and the always growing pressure to either look and feel a certain way. Sociology of the body Sociology of the body is a branch of sociology studying the representations and social uses of the human body in modern societies. According to Thomas Laqueur, prior to the eighteenth century the predominant model for a social