Step-by-step explanation:
most vital organs of circulatory system and respiratory system are protected by the PNS, and epithelial cells that hold organs in its proper cavity.
PNS= Peripheral nervous system, are autonomic systems. unlike the muscles of the body, this system is responsible for breathing, heart beat, and fight or flight response. dont have to think about breathing..it automatically happens, along with heart function.
epithelial cells is the outside lining of circulatory and organ system. allows movement for digestion, breathing, and increased muscle movement,without organs or veins displacing themselves during movement...