Which system works alongside the circulatory system to filter out bacteria?

The lymphatic system plays a critical role in the immune response and works in conjunction with the circulatory system to filter out bacteria, as well as other pathogens and waste products from the body. It is composed of lymph nodes, lymph vessels, and various lymphoid organs that collectively help in the production and transportation of lymph, a fluid that contains white blood cells critical for fighting infections.

When bacteria or foreign invaders enter the body, lymph nodes can detect these threats, prompting an immune response. The lymphatic system helps to track and destroy pathogens, thus preventing the spread of infections. The close relationship between the circulatory and lymphatic systems allows for effective communication and response to threats, as lymphatic vessels transport lymph back into the bloodstream after filtering it.

In contrast, the other systems listed do not serve this specific function. The digestive system primarily focuses on breaking down food and nutrient absorption, the skeletal system provides support and structure to the body, and the reproductive system is involved in reproduction and related processes. None of these systems are directly involved in filtering out bacteria in the way that the lymphatic system is.