Lymphatic Vessels, Lymph Nodes, Spleen, Thymus
Start with the big picture
Lymphatic capillaries collect interstitial fluid through permeable endothelial flaps, and lymph moves centrally through extrinsic forces rather than an intrinsic pump. Major ducts return it to the venous system. Lymph nodes filter lymph and organize immune cells across cortex, paracortex, and medulla; drainage patterns link particular node groups with body regions. The spleen filters blood and has white-pulp and red-pulp functions, with a marginal zone involved in responses to blood-borne pathogens. The chapter also introduces the thymus, including its development, structure, function, distinctive features, and disorders. Clinical context includes increased susceptibility to certain encapsulated bacteria after splenectomy.
What you'll learn
- Explain how lymphatic capillaries collect fluid and support one-way flow.
- Distinguish the drainage territories of the thoracic and right lymphatic ducts.
- Relate lymph-node compartments to their resident cells and functions.
- Contrast the immune and filtering roles of splenic white pulp and red pulp.
- Identify the thymus as a lymphoid organ and outline the lesson’s coverage of its function.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
