A chemical is released by the brain at the start of your REM cycle to paralyze your body. This process is necessary so you do not “act out” your dreams. The sudden jump you experience right before hitting the bottom is your body's response to try and fight the chemical designed to paralyze your body.
REM cycles are extremely important. It allows you to sort out the events of your week, reproduce cells, and restore your body. Another common dream is where your teeth fall out, or they are somehow “knocked” out of your body. The interpretation for this is simple. You have said something that you instantly regret and have hurt someone's feeling unconsciously.
For more dream interpretations, visit
dreammoods.com.