This picture represents a cross section of a lymph node. The arrow indicates the capsule of the lymph node.

Lymph nodes are organs of the lymphatic system located in several areas throughout the body, providing the major site of immune cells, including B and T cells. The lymph node is surrounded by a fibrous capsule, which projects internally to form trabeculae. Lymph nodes consist of an outer cortex and an inner medulla.

From superficial to deep, the lymph node consist of the following components:

• Capsule
• Subcapsular sinus
• Cortex
• Medulla

The capsule of the lymph node consists of dense irregular connective tissue, and from this capsule several trabeculae extend internally. Between the outer cortex and the fibrous capsule is the subcapsular sinus. Lymph flows through afferent lymphatic vessels into the subcapsular sinuses, which then drains into trabecular sinuses and then the medullary sinuses.