Which system is responsible for protecting the body from the external environment?

• A. Nervous System
• B. Integumentary System
• C. Reproductive System
• D. Cardiovascular System

Answer: (B)

The integumentary system is primarily responsible for protecting the body from the external environment. This system includes the skin, hair, nails, and various glands. The skin acts as a physical barrier that prevents pathogens, chemicals, and physical damage from entering the body. It also helps to regulate temperature and prevents dehydration by controlling the loss of water.

In addition to acting as a barrier, the integumentary system is equipped with sensory receptors that detect changes in the environment, informing the body of potential threats such as temperature changes and pain. This feedback loop allows the body to respond appropriately, enhancing overall protection.

Other systems, while crucial for various body functions, do not primarily focus on protection from external factors. For example, the nervous system is responsible for transmitting signals throughout the body and processing information but does not serve as a barrier. The reproductive system is focused on the production of offspring, and the cardiovascular system is involved in the circulation of blood and nutrients. Thus, the integumentary system stands out as the main line of defense against external environmental threats.