Lymphatic System and Lymphoid Organs Study Guide

A comprehensive set of vocabulary flashcards covering the anatomy, functions, and clinical aspects of the lymphatic system and lymphoid organs based on the lecture transcript.

Lymphatic vessels (lymphatics)

An elaborate network of drainage vessels that return excess fluid in body tissues to the blood to maintain blood volume.

Lymph

The name for interstitial fluid once it has entered the lymphatic vessels.

Lacteals

Specialized lymph capillaries present in the intestinal mucosa that absorb digested fat and deliver chyle to the blood.

Chyle

The fatty, lipid-rich lymph delivered from the GI tract to the blood system.

Anchoring filaments

Structures that link endothelial cells to surrounding structures to prevent the collapse of lymphatic vessels.

Right lymphatic duct

The vessel that drains lymph from the right upper arm and the right side of the head, neck, and thorax.

Thoracic duct

The largest lymphatic vessel which drains lymph from the majority of the body, except the right upper side.

Cisterna chyli

A saclike structure at the base of the thoracic duct that receives chyle from the GI tract.

Primary lymphoid structures

Organs involved in the formation and maturation of lymphocytes, specifically the red bone marrow and thymus.

Secondary lymphoid structures

Sites where immune response is initiated and where lymphocytes and other immune cells are housed, including lymph nodes, spleen, and tonsils.

Hematopoiesis

The production of blood's formed elements, which occurs between the trabeculae of spongy bone in the red bone marrow.

T cells (T lymphocytes)

Lymphocytes of the adaptive immune system that manage immune response and may attack and destroy infected cells.

B cells (B lymphocytes)

Lymphocytes of the adaptive immune system that produce plasma cells, which in turn secrete antibodies.

Macrophages

Immune cells that phagocytize foreign substances and help activate T cells.

Dendritic cells

Immune cells that capture antigens and deliver them to lymph nodes to help activate T cells.

Reticular cells

Supporting cells that produce reticular fibers called stroma in lymphoid organs.

Stroma

A network-like support that acts as scaffolding for immune cells within lymphoid tissue.

Thymus

A bilobed lymphoid organ located in the mediastinum involved in T-lymphocyte maturation.

Lymph nodes

The principal secondary lymphoid organs of the body that function to cleanse lymph and provide a site for immune system activation.

Afferent lymphatic vessels

Vessels that bring lymph into a lymph node.

Efferent lymphatic vessels

Vessels through which lymph exits a lymph node; there are fewer of these than afferent vessels to slow the flow of lymph.

Germinal center

An area within the outer cortex of a lymph node that houses proliferating B lymphocytes and some macrophages.

Lymphoma

A malignant neoplasm originating from lymphoid structures, characterized by nontender, enlarged lymph nodes.

Buboes

Inflamed, swollen, and tender lymph nodes that result when the nodes are overwhelmed by what they are trying to destroy.

Metastasis

The process by which cancer cells travel through the lymph and develop in other locations, sometimes making lymph nodes secondary cancer sites.

Spleen

The largest blood-rich lymphoid organ, located lateral to the left kidney, that filters blood and stores RBC breakdown products.

White pulp

Clusters of T- and B-lymphocytes and macrophages around a central artery in the spleen where immune function occurs.

Red pulp

The region of the spleen where old blood cells and bloodborne pathogens are destroyed and where erythrocytes and platelets are stored.

Splenic sinusoids

Very permeable capillaries in the red pulp that allow red blood cells to easily enter and exit the vessel wall.

MALT (Mucosa-associated lymphoid tissue)

Lymphoid tissues located in mucous membranes throughout the body, including the tonsils, Peyer's patches, and appendix.

Peyer’s patches

Clusters of lymphoid follicles located in the wall of the distal portion of the small intestine that destroy bacteria.

Appendix

An offshoot of the first part of the large intestine containing lymphoid nodules to destroy bacteria.

Pharyngeal tonsil

Tonsils located in the nasopharynx, referred to as adenoids when enlarged.

Palatine tonsils

Tonsils located in the posterolateral oral cavity.

Lingual tonsils

Tonsils located along the posterior one-third of the tongue.