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
Catholic theology of the body communicate with him. The human body is the lower element of the human person. Through the body, man experiences his temporal existence. But Gregory also admired human beauty and the bodily abilities to dream, sleep and memorize. The body can be both a friend and enemy of a person, according to Gregory. The final goal is a unity of the soul with God, which is possible with Grace and the assistance of the Holy Spirit according to Gregory. Gregory of Nyssa (335-394) was a bishop who wrote, among others, about the creation of the human body. Unlike Irenaeus, Gregory states,