The Lymphatic System and Lymphoid Organs and Tissues

These flashcards cover key vocabulary related to the lymphatic system and lymphoid organs and tissues, providing definitions to aid in studying for the exam.

Lymphatic System

A system that returns fluids leaked from blood vessels back to blood and plays a crucial role in the immune system.

Lymph

Fluid that circulates in the lymphatic system, consisting of interstitial fluid, proteins, and pathogens.

Lymphatic Vessels

Channels that carry lymph throughout the body, collecting excess fluid from tissues.

Lymph Nodes

Small structures that filter lymph and house lymphocytes, acting as a site for immune response.

Interstitial Fluid

Fluid that surrounds tissue cells and is collected by lymphatic vessels.

Lymphatic Capillaries

Blind-ended vessels that are more permeable than blood capillaries, collecting lymph from the surrounding tissues.

Hydrostatic Pressure

The pressure exerted by a fluid due to its weight, contributing to the movement of lymph.

Colloid Osmotic Pressure

The pressure that draws fluids back into the bloodstream, balancing fluid return from the tissues.

Cisterna Chyli

An enlarged sac at the start of the thoracic duct that collects lymph from the lower body.

Thymus

A primary lymphoid organ where T cells mature; most active during childhood.

B Lymphocytes

White blood cells that produce antibodies and help mark antigens for destruction.

T Lymphocytes

Immune cells that manage the immune response and directly attack infected cells.

Reticular Tissue

Connective tissue that provides a framework for lymphoid organs and tissues.

MALT (Mucosa-associated lymphoid tissue)

Lymphoid tissues found in mucous membranes that protect the body from pathogens.

Peyer’s Patches

Aggregated lymphoid nodules located in the small intestine that monitor intestinal bacteria.

Spleen

The largest lymphoid organ that removes bloodborne pathogens and aged red blood cells.

Macrophages

Immune cells that phagocytize foreign substances and activate T cells.

Glymphatic System

The system involving lymphatic capillaries in the brain that helps drain interstitial fluids.