As an animal develops, the ectoderm becomes the muscle tissue skin and nervous system tissue that lines the body cavity heart

What initially causes a nerve impulse? release of enzymes out of the neuron movement of chemicals into the dendrites of the neuron pathogens attacking the dendrites of the neuron red blood cells bathing the neuron

The fascicles of the deltoid are ; the fascicles of the pectoralis parallel; bipennate fusiform; unipennate multipennate; triangular bipennate; fusiform

Why does the earth spin slowly, not faster? is it possible to prove it scientifically? can you prove it with math?