Human Immune System

The microglia act much like white blood cells by attacking and destroying pathogens that invade the brain. These are extremely small cells of the central nervous system that remove cellular waste and provide protection against microorganisms.

These are of the myeloid lineage which are separated from the monocyte-macrophage lineage after the pluripotent stem cell stage.

The frontal lobes are responsible for problem solving, judgment and motor functioning.

Dendritic cells (DCs) are antigen-presenting cells (also known as accessory cells) of the mammalian immune system. There are several types of dendritic cells, well distributed over the body.

The defensins are peptide antibiotics present in the granules in extremely high concentration.

The enzyme splits starch and is of importance for digestion but not for protection.

B lymphocytes secrete antibodies and cytokines and are responsible for antigen specific humoral responses. They can process and digest antigens particularly in secondary immune responses but do not have a major phagocytic role.

Endothelial cells are not essentially phagocytic although they do contribute by the production of mediators of the inflammatory process, particularly acute inflammation and were previously lumped together with the mononuclear phagocyte system in what was known as the reticuloendothelial system (RES).

T-lymphocytes are specialised for recognising peptides derived from intracellular infectious agents which are exhibited on the surface of an infected cell together with MHC class I & II molecules.

Gamma-interferon activates microbicidal mechanisms within the macrophage, thereby leading to the death of intracellular parasites.

Lymphocytes are not phagocytic, irrespective of their activation status.

Transfection is the introduction of a gene into a cell; calcium phosphate precipitate is one method of achieving this.

They are circulating immature macrophages or dendritic cells.

B-lymphocytes have antibodies on their cell surface which act as an antigen receptor. Upon activation, they differentiate into plasma cells which secrete large amounts of antibodies.

Plasma cells produce immunoglobulins of all isotypes, including IgE.