Chapter_20__Part_I__-_Lymphatic_System

Lymphatic System

The system in the body that drains excess fluid, discards unwanted substances, and aids in immune function.

Lymph

Fluid that is collected from tissues by lymphatic vessels, composed of water, proteins, fats, leukocytes, and waste.

Lymphatic Vessels

Vessels that transport lymph away from tissues, similar in structure to blood vessels but designed to allow fluid and larger molecules to enter.

Afferent Lymphatic Vessels

Lymphatic vessels that carry lymph from tissues to the lymph nodes.

Efferent Lymphatic Vessels

Lymphatic vessels that carry lymph away from the lymph nodes towards the bloodstream.

Lymph Nodes

Small, bean-shaped structures that filter lymph and house immune cells, acting as checkpoints in the lymphatic system.

Lacteals

Lymphatic vessels located in the small intestine that absorb dietary fats.

Mucosa-Associated Lymphatic Tissue (MALT)

Tissue that includes lymphoid follicles found in mucosal membranes, protecting against pathogens.

Spleen

The largest lymphoid organ that filters blood, removes old erythrocytes, and houses white blood cells.

Thymus

A lymphoid organ where T-cells mature and undergo selection processes before entering circulation.

Lymphedema

Swelling due to excess interstitial fluid that occurs when lymphatic flow is obstructed.

Tonsils

Clusters of lymphoid tissue located in the oral and nasal cavities, acting as the first line of defense against inhaled pathogens.

Peyer’s Patches

Clusters of lymphoid tissue located in the ileum of the small intestine that help protect against pathogens.

Reticular Tissue

A type of connective tissue characterized by a network of thin fibers, predominant in lymphoid organs.

Leukocytes

White blood cells that play key roles in immune responses, including lymphocytes, dendritic cells, and macrophages.

Positive Selection (T-cells)

A process in T-cell maturation ensuring that T-cells recognize MHC complexes properly.

Negative Selection (T-cells)

A process in T-cell maturation ensuring that T-cells do not recognize self-antigens as foreign.

Interstitial Fluid

Fluid that occupies the space between cells and is involved in the lymphatic system's fluid regulation.

Cisterna Chyli

A collection of lymph from the intestinal trunk and lumbar trunks, which drains into the thoracic duct.

Thoracic Duct

The largest lymphatic duct that drains lymph from the left side of the body and below the diaphragm into the bloodstream.

Right Lymphatic Duct

Lymphatic duct draining lymph from the right upper side of the body back into the bloodstream.