the lymphatic system and this video is purely dealing with those fast facts those little details that might help with revision so it's rapid revision of the lymphatic system and it's all part of leaving Sur biology the lymphatic system is a secondary circulatory system it's made up of lymphatic vessels which lead into these little structures called lymph nodes and there are also organs that contain lymphatic tissue for example the spleen the tonsils and the thymus land as well the lymphatic vessels are blind ending which means they have a dead end once any substance enters into a lymphatic vessel it's in there and there's no way out until you reach the subclavian veins at the base of the neck the lymphatic vessels are very much like veins and so larger vessels will have valves to prevent the backflow of lymph The Vessel walls can contract but the movement of lymph that's the liquid inside the vessels also requires the contraction of sceletal muscles that's really important all of these vessels the smaller vessels will merge into two larger or main vessels the right lymphatic duct and the thoracic duct really important it's really important that you know quite a few details about lymph the liquid that's transported in this lymphatic system firstly lymph is very similar to tissue fluid or extracellular fluid which is that liquid which bathes every cell in your body it's mostly made up of water really important and it also contains proteins that have leaked out from the blood plasma and must be returned it can also contain waste products such as carbon dioxide and sometimes also bacteria and cancer cells lymph will contain more white blood cells and it also contains the products of fat digestion because fats or the products of fat digestion will enter into the lymphatic system via those Lacs at the center of the Villi lymph is mostly water and it also contains those proteins that have leaked out from the blood plasma and must be returned later on it will contain the products of fat digestion and that turns it to a sort of white creamy color and there can also be bacteria and cancer cells if they're present among the tissues and leak into those lymphatic vessels the lymphatic vessels will feed into these structures known as lymph nodes their job is to filter the lymph they trap pathogens and cancer cells that happen to be in the lymph they house white blood cells so there are lots of lymphocytes B cells and t- cells and macroasia already to capture and deal with any Invaders or any nasty things that are in the lymph that needs to be sorted out the lymphocytes if needed will proliferate so they'll multiply and they'll produce lots of antibodies so it's really important that we have these structures these lymph nodes to filter the lymph and so help us fight disease and infection functions of the lymphatic system to return excess tissue fluid to the blood to return protein to the blood very important for maintaining osmotic balance and the there's that very important role of Defense defense against infection or disease we could also state that the lymphatic system plays a very important role in transporting lipids to the blood those lipids which were absorbed in the small intestine the products of fat digestion are transported in the lymphatic system to the left subclavian vein at the base of the neck so that was the lymphatic system just the fast facts go back and watch the more detailed videos and use your textbook really important don't forget to do the exam paper questions because this topic might be on your exam paper