Immunology Quiz: Thymus and Lymph Nodes

The outermost layer of the thymus, packed with immature T lymphocytes, scattered macrophages, and dendritic cells that help mature T cells.

The innermost layer of the thymus, containing more mature T cells and thymic corpuscles.

Specialized epithelial cells in the thymic cortex that help educate T cells by selecting only those with the potential to become functional.

Small, spherical structures found in the thymic medulla, composed of epithelial cells and involved in the development of immune tolerance.

The thymus differs from other lymphoid organs because it specifically matures T lymphocytes, rather than directly fighting against antigens.

The thymus is composed of star-shaped epithelial cells (not reticular fibers) that secrete hormones to stimulate T cell maturation.

The thymus gradually shrinks in size as we age, from 70g in infants to 3g in older adults.

Small, bean-shaped organs situated along lymphatic vessels throughout the body.

The supporting framework of a lymph node, composed of connective tissue including a capsule, trabeculae, reticular fibers, and fibroblasts.

The functional part of a lymph node, responsible for immune responses.

The outer region of a lymph node, containing B cells organized into clusters called lymphatic nodules or follicles.

The inner region of a lymph node, primarily populated by T cells and dendritic cells.

The innermost region of a lymph node, containing B cells, antibody-producing plasma cells, and macrophages.

The fluid that flows through the lymphatic system, collecting waste and transporting immune cells.

The channels within a lymph node where lymph flows.

The process by which lymph nodes filter out harmful substances, including microorganisms and debris.

Proteins found in blood plasma and cell membranes that enhance certain immune reactions.

A group of proteins that bind iron, preventing its use by bacteria and limiting their growth.

Short peptides with broad antimicrobial activity, often attracting immune cells to the site of infection.

A type of lymphocyte that can destroy infected cells and tumor cells without prior sensitization to a specific antigen.

A process by which phagocytes engulf and destroy microbes or cellular debris.

The largest single mass of lymphatic tissue in the body, responsible for filtering blood, storing blood cells, and playing a role in immune responses.

The structural framework of the spleen, composed of a capsule, trabeculae, reticular fibers, and fibroblasts.

The functional part of the spleen, containing two main regions: the white pulp and the red pulp.

The lymphatic tissue within the spleen, containing lymphocytes and macrophages, primarily responsible for immune functions.

The blood-filled venous sinuses and splenic cords of the spleen, involved in filtering blood, storing platelets, and removing old blood cells.

Specialized cells in the red pulp of the spleen that engulf and break down worn-out or damaged red blood cells, contributing to iron recycling.

One of the functions of the spleen is to provide a site for the proliferation of lymphocytes, which are key players in the immune system.

Another important function of the spleen is to act as a 'checkpoint' for infections, filtering blood for potential threats and initiating an immune response.

The spleen plays a crucial role in clearing the blood of debris, such as old or damaged red blood cells, contributing to blood health.

The spleen stores a significant portion of the body's platelet supply, which are crucial for blood clotting.

Small, isolated clusters of lymphatic tissue scattered throughout mucous membranes, mainly in the digestive, respiratory, and reproductive tracts.

Lymphatic nodules are not enclosed by a capsule. This allows for quick interaction with passing antigens.

These are a type of lymphatic nodules that protect against pathogens entering the body through the respiratory system.

The body's first line of defense against invaders is the skin and mucous membranes.

The skin's outermost layer, composed of tightly packed, dead cells, prevents microbes from entering.

These membranes line the respiratory, digestive, and urinary tracts, trapping microbes and foreign substances.

Tears contain this enzyme that breaks down bacterial cell walls, helping to kill bacteria.

The body's internal defense system includes various substances like interferons and antimicrobial proteins.

These are proteins produced by cells infected with virus, preventing the infection from spreading to uninfected cells.

These substances directly kill microbes or inhibit their growth, acting as important components of the internal defense system.