The Lymphatic System

Capillary Bed As the arterial blood moves in to the capillary bed it is at a high pressure. Blood plasma, minus the blood cells and large protein molecules, is squeezed in to the tissue spaces. Oxygen and nutrients are dissolved in the fluid and are taken up by the cells. At the venous end of the capillary bed some of the fluid is returned to the circulation. The excess tissue fluid is absorbed by the lymph vessels. Tissue Fluid

Lacteals at the centre of the villus The inner wall of the small intestine is shaped like a row of “fingers” called villi. This provides a large surface area for the absorption of nutrients. At the centre of each villus is a lacteal which absorbs fatty acids and glycerol.

Lymph Nodes The lymph nodes filter the lymph as it passes through the node, removing bacteria and other debris. There are various types of leucocyte present. 1. Macrophages are phagocytes which can engulf bacteria. 2. B and T cells are lymphocytes involved in the immune response. 3. Plasma cells produce antibodies.