1) Rigor mortis occurs after a person dies because muscle cells are no longer supplied with ATP. This causes the muscles to become rigid and stuck in position. Based on your knowledge of muscle contraction, why would muscles become rigid, rather than limp, after death?

2) The term fibrillation refers to an irregular, ineffective heartbeat. Do you think ventricular fibrillation is more or less serious than atrial fibrillation in a human? Explain your reasoning.

1.) Rigor mortis, the stiffening of a body several hours after death, arises from a combination of two of the oldest definitions of death - cessation of the heartbeat and cessation of breathing. Once either of these essential functions stops, the cells of the body lose their oxygen supply and can no longer perform aerobic respiration.

Immediately after death, the muscles of the body contract in the same manner as they do when the person is alive. Muscle is formed of bundles of long and narrow cells that can span the entire muscle's length.

In the resting state, these cells build up the electric potential across their membrane by actively pumping out calcium ions. Upon receiving a signal from a neuron, the muscle cells open the calcium channels in their cell membrane, and the calcium ions rush in due to the voltage difference between the inside and outside of the cell.

2.) I think VFib (ventricular fibrillation) is more serious due to the fact that AFib is not normally life threatening and not nearly as much as VFib and the ventricles pour out all to blood to the body making it extremely vital