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
Human Tissue Authority March 2018 by Nicola Blackwood. Its objectives are to: It also acts as the UK competent authority under the EU Tissue and Cells Directives. The Human Tissue Act 2004 repeals and replaces the Human Tissue Act 1961, the Anatomy Act 1984 and the Human Organ Transplants Act 1989 as they relate to England and Wales, and the corresponding Orders in Northern Ireland. The ULTRA (UK agency) and the post of HM Inspector of Anatomy were abolished and their functions transferred to the Authority. The Act makes "consent" the fundamental principle underpinning the lawful storage and use of body parts, organs