4-5 lymph

Function of Lymph Nodes

Filter lymph to remove pathogens and debris; site where lymphocytes are activated to respond to pathogens.

Structure of Lymph Nodes

Encapsulated with dense connective tissue, divided into cortex and medulla.

Cortex of Lymph Node

Outer layer containing lymphoid follicles with germinal centers for B cell activation.

Paracortex of Lymph Node

Area between cortex and medulla; contains T cells and dendritic cells.

Medulla of Lymph Node

Inner area with medullary cords containing B cells, plasma cells, and macrophages.

Afferent Lymphatic Vessels

Vessels through which lymph enters the lymph node.

Efferent Lymphatic Vessels

Vessels through which lymph exits the lymph node at the hilum.

Functions of the Spleen

Filters blood, removes aged or damaged RBCs and platelets, stores platelets and monocytes, initiates immune responses to blood-borne antigens, site of fetal erythropoiesis.

White Pulp of the Spleen

Surrounds central arteries; contains lymphocytes and macrophages; site of immune response.

Red Pulp of the Spleen

Contains sinusoids filled with blood; site of RBC breakdown.