Lymph Nodes Anatomy and Structure

The outer layer of a lymph node, protecting the internal structures.

Extensions of the capsule that divide the lymph node into compartments.

A region in the lymph node containing lymphatic nodules, where B cells are found.

A region beneath the cortex where T cells reside, involved in their activation.

The inner region of the lymph node, containing medullary cords and sinuses.

Long strands of tissue in the medulla containing B lymphocytes, antibody-producing plasma cells, and other immune cells.

Empty spaces in the medulla lined by reticular cells and endothelium, connecting to the capsule.

Lymphatic vessels carrying lymph towards the lymph node.

Lymphatic vessels carrying lymph away from the lymph node.

The primary function of lymph nodes is to filter the lymph, trapping harmful substances and activating immune cells.

Small, bean-shaped organs located along lymphatic vessels, acting as filters for lymph.

The indentation on a lymph node where arteries enter and veins/lymphatic vessels exit.

Lymphatic vessels that bring lymph into a lymph node. They enter at the convex surface.

Dense connective tissue layer surrounding a lymph node, providing structural support.

Internal partitions of connective tissue extending from the capsule into the lymph node, creating compartments.

The functional tissue of a lymph node, composed of the cortex and medulla.

The outer region of a lymph node, characterized by darkly stained lymphatic nodules.

The inner region of a lymph node, lighter in color, lacking lymphatic nodules.

The outer region of the lymph node cortex containing lymphatic nodules, important for B cell activation.

The inner region of the lymph node cortex lacking lymphatic nodules, important for T cell activation.

Lymph nodes are small, bean-shaped organs that filter lymph fluid and house immune cells.

Antigen exposure triggers lymph node proliferation, allowing for a faster and more effective immune response.

Swollen lymph nodes are a sign of inflammation or infection, due to increased lymphocyte production and germinal center formation.

Cancer cells can spread through the lymphatic system, reaching nearby lymph nodes.

Lymph nodes can sometimes successfully eliminate small numbers of cancer cells.

If cancer cells overwhelm a lymph node, they can proliferate and form secondary tumors.

The presence or absence of cancer cells in lymph nodes is crucial for determining cancer stage and prognosis.

The presence of metastatic cancer cells in lymph nodes signifies advanced disease and impacts treatment options.

Doctors use information from lymph nodes to guide treatment plans and predict the likelihood of cancer recurrence.

Lymph nodes play a critical role in the immune system and serve as important indicators of disease progression, particularly in cancer.

Primary nodules are compact masses of B lymphocytes, uniform, deeply basophilic staining, with no germinal center.

Secondary nodules exhibit a light-staining germinal center and a darkly staining peripheral region (mantle zone).

High endothelial venules (HEVs) are specialized blood vessels lined by cuboidal epithelial cells that facilitate lymphocyte migration from the blood into the paracortex.

B lymphocytes migrate to the cortex, while T lymphocytes remain in the paracortex.

Medullary cords are irregular anastomosing cords of B lymphocytes and plasma cells in a network of reticular fibers and reticular cells.

Medullary sinuses are located between medullary cords, lined by discontinuous endothelium, and act as a final lymph filter.

Lymph nodes act as immunological filters, removing bacteria and other foreign materials from the lymph, and facilitating immune responses.

Lymph flows from the afferent lymphatics through the subcapsular sinus, cortical sinuses, medullary sinuses, and finally exits through efferent lymphatics.