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
Explorers of the Human Body Explorers of the Human Body Explorers of the Human Body (Hangul: 인체탐험대; Hanja: 人體探險隊) was one of the three shows of the newly revamped "Good Sunday", a lineup of variety shows that airs every Sunday evening at 5:30 pm KST on SBS. The show's aim was to answer curious questions about the human body, where the Super Junior members perform the answers by doing experiments with their own bodies. The show succeeded in attracting a wide audience due to its comedic and educational content. After previous popular shows "X-Man" and "Reverse Drama" ended, SBS's "Good Sunday" decided to air a