The lymphatic system is made up of lymph nodes, ducts, organs, bone marrow, tissue and vessels.
Lymph vessels have thin-walled valves and carry lymph fluid.
Lymph vessels have a thin layer of smooth muscle tissue and
squamous endothelial cells which line the lymph vessel. The
smooth muscle allows for vasodilation and vasoconstriction.
These lymph vessels have similar structure to blood vessels. The
thin-walled valves prevent backflow of lymph fluid. Fluid is
pushed through the valve into the next chamber when there is
high pressure, the valve will open and once the pressure has
decreased, the open valve will then close to prevent backflow.
The space between two of the semi lunar valves is called a
lymphangion. These valves are small and are thin folds of the
inner lining. They are made of endothelial tissue, and they allow one way flow of lymph fluid. valves are
important for removing waste and prevent infections or cancers from spreading. These valves are
normally found where vessels join or change direction. Lymph vessels are located all over the body
except for bones, teeth and the central nervous system. Peristalsis is generated when smooth muscle in
the lymphangion contracts lymph fluid flows from one lymphangion to another by peristaltic
contractions.
Lymph glands are part of the immune system and help defend
the body against disease and infections by filtering out
substances in the lymphatic fluid. Lymph glands contain white
blood cells and are connected to lymph vessels. They can be
found in your groin, neck, chest, abdomen and armpits. They are
mainly found around major arteries. The lymph node has a
protective outer capsule which separates the node into rooms.
The fluid flows through these rooms and is filtered. Lymph nodes
have a small bean-shaped structure.
Spleen is the biggest organ in the lymphatic system. It is
located just below the diaphragm in the left side of the
abdominal cavity. it is oval shaped and has smooth muscle
fibres as well as dense connective tissue. Inside the spleen is
pulp and lymphatic tissue. White pulp is made up of lymphatic
tissue with macrophages and lymphocytes that are around
blood vessels, and red pulp is made up of blood. Blood is
transported to and from the spleen by the splenic vein and
splenic artery.