Which system is primarily responsible for the body's defense against diseases?

The immune system is primarily responsible for the body's defense against diseases. It comprises a complex network of cells, tissues, and organs that work together to protect the body from infections, pathogens, and various diseases. The immune system identifies and neutralizes harmful invaders, such as bacteria, viruses, and parasites, through a variety of mechanisms including the production of antibodies and the activation of immune cells like lymphocytes.

Understanding this system is critical for estheticians, as treatments and products may impact clients with compromised immune systems or influence how well the skin can heal and fend off infections. Recognizing the importance of the immune system further allows estheticians to tailor their services to support skin health effectively, considering the overall health influences.

In contrast, while the endocrine system regulates bodily functions through hormones, the circulatory system is responsible for transporting nutrients and waste, and the respiratory system facilitates gas exchange. These systems have vital roles, but they do not primarily focus on defending the body against diseases as the immune system does.