Nervous System:

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The nervous system includes two main subsystems: the central nervous system (CNS) including the brain (and the eyes) and spinal cord, and the peripheral nervous system (PNS) including the rest of the body. PNS also has two subsystems: autonomic nervous system connecting our brains to most of our internal organs, and the somatic nervous system controlling voluntary movements and receiving sensory information from the skin, muscles, and tendons—and is responsible for conscious perception of the environment and voluntary responses. The somatic nervous system also includes: 

• Vestibular system is located in the inner ear and is responsible for detecting head movements and maintaining balance. It provides information about the body’s position and orientation in space. 
• Specialized sensory systems controls information, including sound, smell, taste, touch (vision is part of the CNS).
• Balance: Balance is a complex process integrating sensory information from the vestibular system, visual system, and proprioceptive system (the body’s sense of where it is in space). The brain processes this information and sends signals to the muscles to maintain balance.