Answer:
Nervous and endocrine
Explanation:
The nervous system triggers the endocrine system to produce hormones that cause fight or flight
The circulatory system<span> is the transport </span>system<span> for </span>endocrine<span> information. While the nervous </span>system<span> uses neurons, the </span>endocrine<span> chemicals and hormones must circulate through the body via blood vessels. Many glands in your body secrete hormones into the blood.</span>
The two ions are SODIUM AND CALCIUM IONS. Polarization refers to loss of polarization, that is, loss of the difference in charge between the inside and the outside of the plasma membrane of a muscle due to a change in permeability and migration of ion. When a heart muscle is depolarize, sodium ion and calcium ion channels open and they migrate into the cell from the outside.
The average size of a cell in the human body is 100 µm, or 100 micrometers.