For my project, I decided to cover the objectives “Identify the key structures of the Lymphatic System” and “Explain the role the Lymphatic System plays in the Immune Response”. I have related the individual members of the lymphatic system to the different structures that treat sewage: it is comprised of the lymph vessels (sewage pipes), lymph nodes (trickling filters), the spleen (sewage treatment plant), the thymus (primary clarifier) the bone marrow (chlorine contact basin), and the lymph (sewage). High blood pressure forces fluid out of vessels and into interstitial space. This fluid is often carrying pathogens, it is not removed, infection and swelling occur.

Exercise propels interstitial fluid (now called lymph) into the lymphatic vessels and spleen. Lymphocytes and macrophages inside the lymph nodes located along lymphatic vessels destroy pathogens. Likewise, in the spleen, dendritic cells and macrophages purge the lymph and blood of harmful cells. Pure lymph is brought back to the heart and re-enters the blood. In the thymus, T cells are tested for defection, and B cells develop in the bone marrow. Sewage travels by gravity and pumps through pipes to the sewage treatment plant. Unwanted materials are removed by step screens, solid wastes are removed in the primary clarifier, the water is pumped by heavy machinery, and released by trickling filters which help to kill pathogens. Passing through a secondary clarifier and then chlorinated makes this water pure enough to enter rivers.

References: Anatomy and Physiology OpenStax Textbook pages 982-986; YouTube Video by Spanish Fork 17: WasteWater Treatment Plant From Beginning to End; YouTube Video by Collins Learning India: How do wastewater treatment plants work?

I apologize, when I try to access the YouTube Video by Collins Learning India, I get a message that says it is not available anymore, I have triple checked this and I have no idea why the link is not working. I am still able to find it on YouTube when I search by the name of the video, so if you are interested in watching it, that might be the best way to find it.