Lymphatic System and Immunity

These flashcards cover the key concepts of the Lymphatic System and Immunity as discussed in the lecture.

Lymphatic System

A second circulatory system that collects and carries away excess tissue fluid from interstitial spaces, eventually returning it to the blood.

Lymphatic Capillaries

Tiny, closed-ended tubular vessels that extend into interstitial spaces, paralleling the blood capillaries, and receive tissue fluid to form lymph.

Lymph Nodes

Bean-shaped structures that contain lymphocytes, which help defend the body against disease, filtering lymph as it passes through.

Edema

Accumulation of lymph in the interstitial spaces due to interference with lymphatic fluid flow.

Thymus

A bi-lobed organ located behind the sternum that produces T cells and secretes hormones like thymosins to influence T lymphocyte maturation.

Spleen

The largest lymphatic organ that filters blood, removing damaged blood cells and containing white pulp with lymphocytes and red pulp with red blood cells.

Innate Defenses

Nonspecific defense mechanisms that respond quickly to many types of pathogens, including mechanical barriers, inflammation, and phagocytosis.

Adaptive Immunity

Specific immune responses that target particular pathogens, involving lymphocytes and producing memory cells for future responses.

Antigens

Molecules that can evoke an immune response, generally recognized as nonself by the immune system.

Phagocytosis

The process by which cells, such as neutrophils and macrophages, engulf and digest pathogens and debris.