Florida Basic Recruit Training Program High Liability (First Aid) Practice Exam

Which of the following systems protects the body from harmful organisms?

1. Endocrine system

2. Digestive system

3. Skin

4. Circulatory system

The correct answer is: Skin

The skin serves as the body's first line of defense against harmful organisms, such as bacteria, viruses, and fungi. It acts as a physical barrier that prevents the entry of pathogens into the body. The outermost layer of the skin, known as the epidermis, contains tightly packed cells that create a protective layer. Additionally, the skin produces antimicrobial substances and simulates an immune response when it detects pathogens. While the endocrine and digestive systems play crucial roles in overall health and bodily functions, they are not primarily responsible for protecting the body from harmful organisms. The circulatory system is essential for transporting blood, nutrients, and immune cells throughout the body, but it does not provide direct protection against pathogens like the skin does. Therefore, the correct answer highlights the unique protective function of the skin in safeguarding the body from infections.