The lymphatic system is best described as?

• A. A network of nerves and ganglia
• B. Composed of a network of vessels, ducts, nodes, and organs. Provides defense against infection.
• C. Endocrine glands that secrete hormones
• D. Part of the respiratory system

Answer: (B)

Think of the lymphatic system as a network of vessels, ducts, nodes, and organs that transports lymph and defends the body against infection. Lymphatic vessels carry interstitial fluid called lymph back toward the bloodstream, helping maintain fluid balance. As lymph flows through lymph nodes, immune cells inspect it for pathogens and trigger responses if needed. Lymphoid organs such as the spleen, thymus, and tonsils support immune cell development and provide filtering and defense. This system is distinct from the nervous, endocrine, and respiratory systems, yet it plays a central role in immune protection and fluid management.