The figure below shows the two main families of acetylcholine receptors: muscarinic and nicotinic. In structural terms, muscarinic receptors are G-coupled protein receptors, while nicotinic receptors are ligand-gated ion channels. They can be found on both sides of the synaptic cleft (presynaptic and postsynaptic).
After the pressure drops below 40 psi, the electrical switch turns on the pump and the pressure in the tank increases. Any failure in any component or loss of electricity can cause a well to suddenly stop producing water when a faucet is turned on.
A. No. Sewage pumps are designed for short periods of operation. Running a sewage pump for too long can cause the pump to overheat. It is also oil-filled. If fish waste attacks the pump seals, or it overheats, that oil can be discharged into your water feature. That will kill the fish and plants. When it cools, it will draw water up inside the pump motor which will kill the pump.