Which of the following is/are classified as an accessory organ of the urinary system?

A. Fluid balance and waste removal: The lymphatic system helps return excess interstitial fluid to the bloodstream, which contributes to fluid balance. However, the removal of metabolic waste products such as urea or carbon dioxide is primarily handled by the kidneys, liver, and lungs.

B. Fluid balance and immunity: The lymphatic system maintains fluid homeostasis by collecting excess tissue fluid and returning it to the circulatory system, preventing edema. It also plays a critical role in immunity: lymph nodes filter pathogens, and lymphocytes and other immune cells respond to infections. These two functions are considered its most essential roles in maintaining overall health.

C. Immunity and waste removal: While the lymphatic system is central to immune surveillance and defense against pathogens, it does not serve as a primary pathway for removing metabolic or cellular waste. Relying on lymphatic vessels for waste elimination would be ineffective, as the system is specialized for fluid transport and immune cell trafficking rather than excretion.

D. Waste removal and gas exchange: Gas exchange occurs in the alveoli of the lungs, and metabolic waste is removed mainly by the kidneys, liver, and lungs. The lymphatic system does not participate in oxygen or carbon dioxide transport, and its role in waste management is limited to transporting interstitial fluid rather than systemic excretory function.

A. Cardiac: Cardiac tissue is a specific type of muscle tissue found in the heart. While it is important for heart function, it is not classified as one of the four principal tissue types of the body. It is a subset of muscle tissue rather than a principal category.

B. Epithelial: Epithelial tissue covers body surfaces, lines cavities, and forms glands. It serves protective, absorptive, secretory, and sensory functions and is one of the four primary tissue types.

C. Nervous: Nervous tissue is composed of neurons and supporting cells. It is responsible for transmitting electrical impulses, processing information, and coordinating body activities, making it a principal tissue type.

D. Connective: Connective tissue supports, binds, and protects organs and structures. Examples include bone, cartilage, blood, and adipose tissue. It is one of the four principal tissue types of the body.

E. Muscle: Muscle tissue is specialized for contraction and movement. It includes skeletal, cardiac, and smooth muscle, and is a primary tissue type essential for locomotion, circulation, and organ function.