Lymph Node Anatomy Explained: Cortex, Paracortex, Medulla and Lymph Flow

Overview

This short video explores the lymphatic system and lymph nodes, detailing how interstitial fluid drains into the lymph and how lymphoid tissues host immune cells. It covers primary and secondary lymphoid organs, the capsule and trabeculae of lymph nodes, and the flow of lymph through subcapsular sinuses to efferent vessels.

• Lymph nodes filter lymph to identify infections
• Outer cortex contains B cell follicles with germinal centers
• Inner cortex features high endothelial venules for lymphocyte entry
• Medulla houses medullary cords and sinuses guiding lymph out of the node

Introduction to the Lymphatic System

The video introduces the lymphatic system as a key part of the immune defense. It explains that lymphatic vessels drain interstitial fluid (lymph) from peripheral tissues back into the bloodstream. Lymphoid tissues are rich in lymphocytes and other white blood cells, and the system is organized into primary (thymus and bone marrow) and secondary (tonsils, lymph nodes, spleen, and mucosa) lymphoid organs along with associated lymphoid tissue (MALT).

"Lymph nodes filter the lymph flowing through vessels to identify and fight infections" - Unknown Presenter