Immune system overview

What is the role of the lymphatic system in immunity?

The lymphatic system supports immunity by returning excess fluid to the bloodstream and contains many structures that function as key immune organs.

What are lymph nodes and their function?

Lymph nodes are bean-shaped filtering stations along lymphatic vessels that filter interstitial fluid and remove pathogens using macrophages.

What is produced in red bone marrow?

Red bone marrow produces lymphocytes and is the site of B-cell maturation.

What does the spleen do in the immune system?

The spleen filters blood and removes pathogens through macrophages.

What is the function of the thymus in immunity?

The thymus is the site of T-lymphocyte maturation.

Which immune cells are involved in phagocytosis?

Macrophages, dendritic cells, and neutrophils destroy pathogens by phagocytosis.

What is the role of natural killer cells?

Natural killer cells non-specifically destroy infected cells.

What do B lymphocytes produce?

B lymphocytes produce antibodies that target specific antigens in body fluids.

How do T lymphocytes function?

T lymphocytes target cells infected by specific pathogens.

What are the two branches of immunity?

The two branches of immunity are nonspecific (innate) and specific (adaptive) responses.

What are MHC class I proteins?

MHC class I proteins are present on every nucleated cell and serve as the general 'self' marker.

Why can organ transplants be rejected?

High genetic variation in MHC alleles means MHC markers are unique except in identical twins, which can lead to organ transplant rejection.

What are MHC class II proteins?

MHC class II proteins are found on antigen-presenting cells and link innate and adaptive responses by displaying pathogen information.

What is an antigen?

An antigen is a protein or large carbohydrate that is unique to a pathogen.

What is antigen presentation?

Antigen presentation is the process by which macrophages and dendritic cells ingest pathogens, digest them, and display fragments of their antigens on their surface.