Body systems part 2

The nervous system controls both voluntary actions (like conscious movement) and involuntary actions (like breathing), and sends signals to different parts of the body. The body’s muscular system consists of about 650 muscles that aid in movement, blood flow and other bodily functions. The reproductive system allows humans to reproduce. Our bodies are supported by the skeletal system, which consists of 206 bones that are connected by tendons, ligaments and cartilage. The skeleton helps support our body for movement. The respiratory system allows us to take in vital oxygen and expel carbon dioxide in a process we call breathing. The urinary system helps eliminate a waste product called urea from the body, which is produced when certain foods are broken down. The skin system is the body’s largest organ. It protects us from the outside world, and is our first defense against bacteria, viruses and other pathogens. Our skin also helps regulate body temperature and eliminate waste through perspiration.

Question:

1. What do our cells need to function?
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2. What causes people to become overweight?
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3. How many amino acids make up proteins and how do they become three-dimensional shapes?
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