What keeps equilibrium with in the human body?

Question

also, what is responsible for linear acceleration and gravity?

Answer 1

Equilibrium is maintained by the lungs, kidneys, and skin.

When discussing equilibrium, the two main concerns are pH and temperature.  WHY?  Both pH and temperature must be kept within a range that allows enzymes to work.  The chemical activity of life are too slow to keep an organism alive.  So, the main function of a cell is to produce enzymes which are chemicals that speed up the chemical reactions of life.  Without enzymes, there is no life.

However, enzymes are very sensitive to pH and temperature.  Therefore, our lungs and skin help to regulate temperature.  The kidneys help to regulate the pH of the internal environment to keep it in a very small range.  

Post your other two questions on the physics board.