Human Immunology and Lymphatic System Quiz

The ability to ward off disease or damage through the body's defenses. There are two types: innate and adaptive.

Innate immunity is present at birth and does not require prior exposure to a pathogen. It offers nonspecific recognition of invaders and lacks a memory component. It involves the first and second lines of defense.

Adaptive immunity is acquired through exposure to pathogens. It provides specific recognition of invaders and has a memory component. This means the body remembers the pathogen and can fight it off more effectively in the future.

This system gathers and filters excess interstitial fluid, transports ingested fats, and plays a crucial role in immune responses. It comprises lymph, lymphatic vessels, structures, and organs containing lymphatic tissue, and red bone marrow.

Lymphatic capillaries are thin, closed-ended vessels that collect excess interstitial fluid. They are slightly larger than blood capillaries and have a unique one-way structure that allows fluid to enter but not exit. Anchoring filaments help widen the openings when fluid accumulates.

Lymph trunks are formed when lymphatic vessels converge. Major trunks include the lumbar, intestinal, bronchomediastinal, subclavian, and jugular trunks. These trunks drain into the thoracic and right lymphatic ducts before emptying into venous blood.

This refers to the process by which more fluid filters out of blood capillaries than is reabsorbed. The excess fluid, approximately 3 liters per day, becomes lymph and enters lymphatic vessels. The lymphatic system plays a vital role in returning lost plasma proteins to the bloodstream.

The lymphatic system and the cardiovascular system work closely together. Lymph eventually empties into the blood, maintaining fluid balance, and contributing to immune responses. The lymphatic system also plays a role in transporting dietary fats absorbed from the small intestine.

The thymus is a primary lymphoid organ responsible for the maturation of T lymphocytes.

The thymus has two lobes, each containing an outer cortex and an inner medulla.

The thymus cortex is densely packed with lymphocytes, which are immature T cells that proliferate and mature. Specialized epithelial cells in the cortex guide T cell maturation through a process called positive selection, where only about 25% of T cells survive.

The thymus medulla contains mature T cells that have migrated from the cortex, along with epithelial cells, dendritic cells, and macrophages. It is also characterized by the presence of thymic corpuscles, which are small, round structures.

The thymus starts to shrink with age, indicating a decline in its activity. This process begins around puberty and continues throughout adulthood.

Supporting connective tissue in lymph node, providing structure and framework.

Functional part of lymph node where immune responses happen.

Outer region of lymph node containing B cells in clusters, where plasma cells and memory B cells are formed.

Inner region of lymph node, mainly containing T cells and dendritic cells.

Central region of lymph node containing B cells, antibody-producing plasma cells, and macrophages.

Fluid flowing through lymph nodes, carrying cells and substances.

Vessels that carry lymph into a lymph node.

Vessels that carry lymph out of a lymph node.

A process where a lymphocyte specifically multiplies and differentiates in response to a particular antigen.

A group of genetically identical cells, all recognizing the same antigen as the original cell.

Lymphocytes undergo clonal selection within secondary lymphatic organs, such as lymph nodes and tonsils.

The immune system's ability to recognize and bind to a vast number of different epitopes.

The specific part of an antigen that is recognized by the immune system (antibodies, B cells, or T cells).

The ability of an antigen to trigger an immune response.

The ability of an antigen to specifically react with the antibodies it provoked.

Proteins found on the surface of most body cells, helping T cells identify foreign or self antigens.

Lymphatic nodules are small, un-encapsulated collections of lymphatic tissue found scattered in the mucous membranes lining the digestive, urinary, and reproductive systems. They are also found in the respiratory system, forming a specialized layer known as mucosa-associated lymphatic tissue (MALT). Lymphatic nodules are mostly small and solitary but can be larger, like tonsils, Peyer's patches, and the appendix.

Lymph fluid, which is a clear fluid containing white blood cells, flows through a network of lymphatic vessels. This system gathers and filters excess fluid from tissues, transports fats absorbed from the intestines, and plays a crucial role in immune responses.

Lymphatic vessels are thin tubes that collect lymph fluid from tissues and carry it towards the heart. They are similar to veins in structure and function, having one-way valves that prevent backflow.

Lymphatic tissue is found in various organs and structures of the lymphatic system, including lymph nodes, spleen, tonsils, and thymus. It is composed of specialized cells, including lymphocytes, macrophages, and other immune cells that play a crucial role in fighting infections.

Lymph nodes are small, bean-shaped organs found along lymphatic vessels. They filter lymph fluid, trapping foreign substances and pathogens. Lymph nodes house lymphocytes, which attack and destroy invading microorganisms.

The spleen is a large, oval-shaped organ located in the upper left abdominal cavity. It filters blood, removing old or damaged red blood cells. It also contains white blood cells, which help fight infections and produce antibodies.

The thymus is a small, bilobed organ situated in the chest. It is the primary site where T lymphocytes mature and differentiate, becoming specialized immune cells that can recognize and destroy specific pathogens.

Tonsils are clusters of lymphatic tissue located in the throat. They form a protective barrier against pathogens entering the body through the mouth and nose. They also contain lymphocytes, which help fight infection.

Antigenic proteins are broken down into smaller pieces and presented in conjunction with MHC molecules on the cell surface.

Antigen-MHC complexes are displayed on the plasma membrane for T cells to recognize.

Antigens are processed differently depending on whether they are encountered outside or inside bodily cells.

Cells that present antigens to T cells, including dendritic cells, macrophages, and B cells. They are found at the points of entry for pathogens, such as the skin and mucous membranes.

Antigens present in fluids outside of body cells.

Antigens present inside body cells.

APCs engulf exogenous antigens, process them, and present them alongside MHC-II molecules on their surface.

Infected cells process and present endogenous antigens with MHC-I.

APCs migrate to lymphatic tissue to present processed antigens to T cells.

T cells recognize antigen fragments presented in antigen-MHC complexes on the surface of APCs. This initiates T cell activation.

Second signal needed for full T cell activation. It ensures that T cells do not mistakenly attack healthy cells.

Helper T cells (CD4+ T cells) recognize exogenous antigens presented with MHC-II.

Cytotoxic T cells (CD8+ T cells) recognize endogenous antigens presented with MHC-I. They directly kill infected cells.

Cytotoxic T cells release cytotoxic substances (granzymes and perforin) that kill infected cells.

B cells recognize antigens directly and process them. Helper T cells provide costimulation for full activation.