Chapter 21- The Immune System Part 1

keratin

a thick protein resistant to the acids and bases secreted by most bacteria

Fever

abnormally high body temperature. This is another defense against infection. Hypothalamus response to microbial invasion

Eosinophils

another type of leukocyte in the body, these can be phagocytic but they are best known for fighting parasitic worms.

Fixed Macrophages

are permanent residents of specific organs in the body. Kupffer Cells are an example

Antimicrobial Proteins

attack microbes directly or they limit the ability of microbes to reproduce

Inflammation

begins when chemicals and cells leave blood vessels and move into the injured tissue. Chemicals such as cytokines, histamine, kinins and prostaglandins all promote small blood vessels in the injured area to dilate; thus increasing blood flow to the area

Free Macrophages

can move throughout the body searching for and destroying foreign invaders. Alveolar macrophages are an example

Natural Killer Cells

cells in the blood and lymph that can lyse and kill cancer cells and virus-infected cells before the adaptive immune response is initiated. not specific and they develop from granular leukocytes. proteins on the specific cell identify this cells. Non-phagocytic

Phagocytes

cells that feed on and destroy invading microorganisms

perforins

destroy the nucleus of cells

inflammatory response

initiated when body tissues are injured. The primary goal of inflammation is to clear the injured area of pathogens, dead cells and any other debris so that tissue repair can begin

The Classical Pathway to activate Complement System

involves the formation of antibodies to destroy invading microbes.

The Lectin Pathway to activate Complement System

involves the release of proteins known as lectins that attach to foreign invaders, thus triggering complement Proteins.

Mucous Membranes

line body cavities that open directly to the outside of the body

Neutrophils

most abundant type of leukocyte in the body, these become phagocytic upon encountering infectious materials in the body.

The Alternative Pathway to activate Complement System

occurs when certain complement proteins are triggered by polysaccharides on the membranes of invading microorganisms.

swelling

occurs when chemicals increase the permeability of blood vessels so that cells and antibodies can move into the injury site

abscess

occurs when pus accumulates material, is not removed, and is walled off by collagen fibers. Must be surgically removed

Beta defensins

often released in the injury site during inflammation. These antibiotic type agents function by fighting bacterial growth

Surface barriers or external body membranes

prevent the penetration of pathogens into the body. produce a number of chemicals that provide protection for the body

Macrophages

primary phagocytes in the body. These are derived from leukocytes known as monocytes which leave the bloodstream, enter tissues and develop into macrophages.

Opsonization

process in which proteins and antibodies coat the outer covering around a pathogen. This provides "handles" for the phagocyte to attach to; thus increasing the efficiency of phagocytosis.

Interferons

proteins secreted by some cells that are infected by viruses. These proteins stimulate healthy cells to produce a protein known as PKR which functions by preventing viruses from undergoing protein synthesis.

Diapedesis

the movement of neutrophils through the walls of capillaries into the site of inflammation

Adherence

the phagocyte adheres to the pathogen. This is accomplished when the phagocyte recognizes either the protein or carbohydrate signature of the pathogen.

Leukocytosis

the release of phagocytic cells (especially neutrophils) into blood vessels. Within hours, these cells are transported to the site of injury.

Complement System

this refers to a group of plasma proteins that circulate through the blood in an inactive state. These proteins are activated by the immune response itself.

INNATE (NONSPECIFIC) DEFENSES

this system responds quickly to protect the body from pathogens and infection

Inflammation

which includes a variety of proteins, cells and phagocytes which work together to prevent the spread of pathogens throughout the body