THE NERVOUS SYSTEM
The structures and functions of the body's Nervous System
Levels of Orginization - Cells and Tissue
Levels of organization - organs and organ systems
Levels of organization - organism
The nervous system allows you to act and react, so it allows your body to make certain actions and reactions depending on the temperature around you. For example, if you are cold, the nervous system will send an electrical message to your muscles to wrap your arms around your chest.
If the nervous system fails to get information outside the body, there can't be electrical messages sent to muscles to react. An example is when someone is paralyzed from breaking their neck. If the neck breaks, the spinal chord can't send messages to your arms or legs.
Stroke, Parkinson's disease, and other diseases or body problems like sclerosis can affect memory and keep the body from performing certain activities we as humans do daily.