Which characteristic is true about lymphatic capillaries?

Lymphatic capillaries are indeed characterized by being closed off at one end. This structure allows them to function effectively in the lymphatic system. Unlike blood capillaries, which connect arteriole and venule systems, lymphatic capillaries collect excess interstitial fluid and return it to the circulatory system. The closed end of these capillaries allows them to take in fluid, proteins, and other solutes from the surrounding tissues, which are then transported as lymph.

The design of lymphatic capillaries facilitates their role in collecting lymph as they can absorb larger molecules and fluid that cannot re-enter blood capillaries due to their size. This unique feature distinguishes them from other types of vessels in the circulatory system, further emphasizing their specialized function. Additionally, while lymphatic capillaries do have valves to prevent backflow, this characteristic is not exclusive to them; rather, it is a general feature of larger lymphatic vessels. The primary role of lymphatic capillaries is not the transportation of nutrients, making the closed-ended design essential for their function in maintaining fluid balance in the body.