Which structures are included in the lymphatic system?

Which structures are included in the lymphatic system?

• A. Heart, arteries, capillaries
• B. Lymph nodes, lymph, tonsils, thymus, spleen
• C. Kidneys, ureters, bladder
• D. Pancreas, liver, gallbladder, bile duct

Answer: (B)

The lymphatic system includes structures that transport and filter fluid and support immune responses, such as lymph, lymphatic vessels, lymph nodes, and lymphoid organs like tonsils, thymus, and spleen. Lymphatic vessels carry lymph, a fluid that collects excess tissue fluid and immune cells; lymph nodes act as filters where immune cells can encounter pathogens; tonsils are immune tissues at the throat; the thymus is where certain immune cells (T cells) mature; and the spleen helps filter blood and coordinate immune responses. The other options belong to different body systems—cardiovascular (heart, arteries, capillaries), urinary (kidneys, ureters, bladder), and digestive (pancreas, liver, gallbladder, bile duct)—so they don’t fit as components of the lymphatic system.

The lymphatic system includes structures that transport and filter fluid and support immune responses, such as lymph, lymphatic vessels, lymph nodes, and lymphoid organs like tonsils, thymus, and spleen. Lymphatic vessels carry lymph, a fluid that collects excess tissue fluid and immune cells; lymph nodes act as filters where immune cells can encounter pathogens; tonsils are immune tissues at the throat; the thymus is where certain immune cells (T cells) mature; and the spleen helps filter blood and coordinate immune responses. The other options belong to different body systems—cardiovascular (heart, arteries, capillaries), urinary (kidneys, ureters, bladder), and digestive (pancreas, liver, gallbladder, bile duct)—so they don’t fit as components of the lymphatic system.