innate defenses
surface barriers and internal defenses (nonspecific)
adaptive defense system
Third line of defense attacks particular foreign substancesTakes longer to react than innate system
humoral immunity
B cells
What are the two adaptive defenses?
humoral immunity and cellular immunity
cellular immunity
T-cells (cell mediated)
second line of defense
phagocytes, inflammation, fever, antimicrobial substances
phagocytes types
neutrophils and macrophages
Neutrophils
Most abundant white blood cell., The most abundant type of white blood cell. Phagocytic and tend to self-destruct as they destroy foreign invaders, limiting their life span to a few days.
Monocytes
*A type of white blood cell that transforms into macrophages, extends pseudopods, and engulfs huge numbers of microbes over a long period of time*An agranular leukocyte that is able to migrate into tissues and transform into a macrophage.
natural killer cells
A type of white blood cell that can kill tumor cells and virus-infected cells; an important component of innate immunity.
Interferons
proteins (cytokines) secreted by T cells and other cells to aid and regulate the immune response
Histamine
Chemical stored in mast cells that triggers dilation and increased permeability of capillaries.
complement system
proteins in the blood that help antibodies and T cells kill their target
Cytotoxic T cells
T cells, often called killer cells because of their capability to kill invading organisms. (Apoptosis)
Perforin
a protein, released by killer cells of the immune system, that destroys targeted cells by creating lesions like pores in their membranes.
B cells
produce antibodies. Memory cell
antibody
A protein that acts against a specific antigen. Secreted by B cells
IgG
crosses placenta
IgM
first to increase in immune response
IgD
Attached to B cells Activates B cells
IgA
Secretions. Stop bacteria from adhering, prevent bacterial colony formation.Found in mucous, saliva, tears
IgE
allergic reactions