Cytokines are molecules that primarily do what in health and disease?

• A. Mediates communication between the nervous system and immune system
• B. Break down pathogens
• C. Transport oxygen in the blood
• D. Store energy

Answer: (A)

Cytokines are signaling proteins that coordinate how immune cells communicate, shaping inflammation, cell growth, and responses to infections. They also form a bridge to the nervous system, influencing fever, sleep, and other CNS responses—this neuroimmune communication is a key aspect of how the body coordinates defense and repair across systems. That bridging function is Why this option fits best: cytokines mediate communication between the nervous system and immune system, rather than directly breaking down pathogens, transporting oxygen, or storing energy. Direct pathogen destruction comes from other immune mechanisms, not cytokines themselves.