The respiratory system regulates oxygen flow, and provides regulation for oxygen blood content. Circulatory system plays a roll in providing enough oxygenated blood to the body
Explanation:
Fear is a barrier as people fear being judged for things as there might be a stigma attached to it. When people are judged their problem isn't solved and instead worsened and they will feel compelled to keep their problems to themselves.
Lets consider the water drop as being part of the water in a lake. The water droplet evaporates and changes from a liquid state to a vapor state by gaining energy and travels up to the upper atmosphere. In the atmosphere the water droplet once again condenses in the clouds and is stored until it can be precipitated on to the land again in the form of rain or other forms of precipitation.