Organs and Tissues of the Immune System

A set of flashcards covering key vocabulary and concepts related to the organs and tissues of the immune system.

Primary Lymphoid Organs

Organs involved in lymphocyte development and maturation, including bone marrow, thymus, fetal liver, and yolk sac.

Secondary Lymphoid Organs

Organs that support lymphocyte maturation, survival, and activation, such as the spleen, tonsils, lymph nodes, and mucosa-associated lymphoid tissues (MALT).

Hematopoiesis

The process of blood cell production, primarily occurring in the fetal liver during early development before bone marrow function begins.

Yolk Sac

A structure that supports an embryo by providing nutrients, circulating gases, and early immune function.

Thymopoietin

A hormone from the thymus gland that stimulates the production of T-cells.

Splenic Hemangioma

A type of tumor occurring in the spleen, relatively common in dogs.

Tonsillitis

Inflammation of the tonsils caused by viral or bacterial infections, with marked species differences in presentation.

MALT

Mucosa-associated lymphoid tissue, a network of lymphoid tissues protecting mucosal surfaces against pathogens.

Peyer's Patches

Aggregated lymphoid nodules located in the wall of the small intestine, important for immune surveillance and response.

Immune Function of Bone Marrow

Production of all blood cells and maturation of B-lymphocytes.

Clinical Relevance of Thymus Gland

Essential for developing normal cell-mediated immunity; disorders can lead to immunodeficiency or autoimmune diseases.

Functions of the Spleen

Filters blood, activates lymphocytes, produces antibodies, destroys aging RBCs, and recycles iron.

Antigen Presentation

The process by which immune cells display antigens to activate specific lymphocytes.

IgA

An antibody that plays a crucial role in mucosal immunity, produced by tonsils.