Understanding Infectious Diseases and the Immune System

Infectious Disease

is caused by agents that have invaded the body

Pathogen

any agent that causes disease

Koch Postulates

rules for determining the cause of a disease

Mucous Membrane

epithelial tissue that protects the inferior surface of the body that might be exposed to pathogens

Inflammatory Response

events that suppress infection and speed recovery

Histamine

substance that increases the permeability of surrounding capillaries

Phagocytes

type of white blood cell that pass through capillary walls, ingest and destroy foreign matter

Neutrophil

type of phagocyte that squeeze through capillary walls

Macrophage

type of phagocyte that engulfs pathogens and cellular debris

Natural Killer Cells

large white blood cells that attack pathogen-infected cells

Complement System

proteins that become active when they encounter certain pathogens

Interferon

protein released by cells infected with viruses

Immune System

group of cells and tissue that recognize and attack foreign substances providing specific defenses

Lymphocyte

WBC of the immune system

Thymus

gland located above the heart that helps produce more lymphocytes

Spleen

large lymphatic organ that stores blood cells, breaks down aged blood cells, and helps with the development of WBC

T Cell

lymphocyte made and mature in bone marrow and mature in the bones

B Cell

lymphocyte made and matured in the bone marrow

Antigen

any substance that triggers an immune response

Immune Response

reaction of the body against an antigen

Helper T Cell

WBC needed for the development of antibodies

Cell-Mediated Immune Response

immune response that functions to defend cells against invasion of foreign substances

Cytotoxic T Cell

they recognize and destroy cells infected by pathogens

Humoral Immune Response

response that is produced by the action of antibodies

Plasma Cell

specialized cells that make proteins called antibodies

Antibody

protein that reacts to a specific antigen

Memory Cell

lymphocyte that only responds to the second attack of antigens

Immunity

ability to resist and infectious disease

Vaccination

introduction of antigens in the body to cause immunity

Allergy

physical response to an antigen

Asthma

respiratory disorder that causes the bronchioles to narrow

Autoimmune Disease

disease in which the immune system attacks the organism's own cells

AIDS

one of the deadliest diseases, the immune system loses its ability to fight off pathogens and cancers

HIV

AIDS results from infection by the human immunodeficiency virus

Opportunistic Infection

illness caused by pathogens that produce disease in people with weakened immune systems