Immune System

Immune System

Defends the body against pathogens like bacteria, viruses, tumors, parasitic worms, fungi, protozoa.

First Line of Defense

Includes skin, mucous membranes, hairs, and acids in the stomach.

Non-Specific Response

Body's general awareness of foreign presence without specific identification.

Specific Response

Body's targeted defense using specialized cells and antibodies.

Mast Cells

Produce histamine when sensing invasion

Histamine

Substance causing allergic reactions like redness, swelling, and mucus production.

Phagocytes

White blood cells recognizing antigens on pathogens and destroying them.

Macrophages

Phagocytes engulfing and destroying pathogens and dead cell remains.

Plasma B Cells

Recognize antigens and produce antibodies against foreign invaders.

Antibodies

Proteins attaching to antigens to help destroy pathogens.

Memory B Cells

Cells that remember antigens for quick responses to future exposures.

Helper T Cells

Activate B cells in the immune response.

Killer T Cells

Destroy virally infected cells and tumor cells.

Antibiotics

Kill bacteria but not viruses.

Vaccine

Weakened form of a disease stimulating antibody production and B cell activation.

Antibody

Y-shaped molecule produced by plasma cells in response to pathogens.

Virus

Pathogen consisting of a protein coat and nucleic acid core.