35.2

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NONSPECIFIC DEFENSES

Skin

Tears

Lysozyme enzyme that breaks down bacterial cell walls

Other secretions (like mucous)

Inflammatory response

Interferons

Fever

*first line of defense

*second line of defense

INFLAMMATORY RESPONSE

Infected areas become red and painful (inflamed)

HISTAMINES

Chemical that increases flow of blood and fluids to the affected area (p. 1015)

INTERFERONS

Proteins released by a host cell getting “attacked” by a virus that inhibits synthesis of viral proteins

FEVER

Increase body temperature

Slows down or stops the growth of some pathogens

***remember…a lot of bacteria/ pathogens can’t withstand high heat!***

SPECIFIC DEFENSES

Immune system’s specific defenses distinguish between “self” and “other,” and they inactivate or kill any foreign substance or cell that enters the body.

*respond to a particular pathogen!*

IMMUNE RESPONSE

Body doesn’t recognize something

Goes into an IMMUNE RESPONSE

Specific recognition, response and memory to pathogens

ANTIGENS VS. ANTIBODIES

Antigen any foreign substance that can stimulate an immune response

Antibodies tags antigens for destruction by immune cells

LYMPHOCYTES

B lymphocytes and T lymphocytes are the main working cells of the immune systems

The specific immune response has two main styles of action…humoral immunity and cell-mediated immunity

Humoral refers to the immune response that happens in body fluids (B cells)

Cell-mediated (T cells) defends the body against some viruses, fungi, and single-celled pathogens