Columbus State University 2

Overview of Lymphatic System

• Lymph: Clear fluid recovered from tissues by lymphatic vessels.

• Lymphatic Vessels: Transport lymph throughout the body, similar to blood vessels.

Lymphocytes and Macrophages

• Lymphocyte: Type of white blood cell (leukocyte).

• Macrophage: Monocyte that resides in tissue, involved in immune response.

Composition of Lymph

• Lymph resembles plasma, generally clear; varies by body location.

• Collects fluid that remains post-circulation or outside cells; does not gather intracellular fluid.

• Composition can vary due to proteins and different mechanisms regulating fluid levels.

Structure of Lymphatic Capillaries

• Similar to blood capillaries but with valves (valve-like flaps) that prevent backflow.

• Overlapping endothelial cells form flaps, allowing fluid entry based on pressure change.

• Anchored to tissues by filaments for stability.

Function of Lymphatic System

• Aids in fluid balance by returning excess fluid to the circulatory system.

• Helps regulate blood volume—important for maintaining blood pressure.

Anatomy of Lymphatic Vessels

• Lymphatic vessels consist of three layers, thinner than blood vessels.

• Even larger lymphatic vessels are not as extensive as blood vessels.

Role of Lymph Nodes

• Lymph nodes filter lymph, essential for immunological responses.

• Cancer cells or viral particles can be captured here, highlighting the role of lymph nodes in immune defense.

Immune Cells in Lymphatic System

• Key immune cells include B cells and T cells, crucial for adaptive immunity.

• T lymphocyte production and function can be impacted by loss of the thymus.