Chapter 22 - The Immune System

Flashcards for Chapter 22 - The Immune System

What are the different classes of infectious agents?

Bacteria, viruses, fungi, protozoans, and multicellular parasites

Give an example of a bacterial infection.

Tetanus and strep

Give an example of a viral infection.

Colds, Ebola, and chickenpox

Give an example of a fungal infection.

Ringworm and yeast infections

Give an example of a protozoan infection.

Malaria and trichomoniasis

Give an example of a multicellular parasite infection.

Tapeworms

What blood cell has immune function?

Leukocytes

What cells are granulocytes?

Neutrophils, basophils, and eosinophils

What cells are agranulocytes?

Monocytes and lymphocytes

What do monocytes become when they leave the blood?

Macrophages

What types of lymphocytes are there?

B-lymphocytes, T-lymphocytes, and NK cells

What are cytokines?

Small proteins that help regulate immune activity

What are the functions of cytokines?

Signal cells, control the development of immune cells, regulate the inflammatory response, destroy cells

What is innate immunity?

Present at birth, nonspecific protection, no prior exposure needed

What does innate immunity include?

Skin and mucous membrane barriers, nonspecific internal defenses

What is adaptive immunity?

Acquired, specific response to antigens, takes several days

Is the first line of defense innate or adaptive?

Innate

What are some examples of the first line of defense?

Skin and mucous membranes

Besides physical barriers, what else provides protection in the first line of defense:

Sweat, sebum, mucus, and antimicrobials

Is the second line of defense innate or adaptive?

Innate

What are some examples of the second line of defense?

Cells, chemicals and the complement system, inflammation and fever

Name the phagocytic cells

Neutrophils, macrophages, dendritic cells

Name the proinflammatory cells and chemicals

Basophils, mast cells, eicosanoids

Name the apoptosis initiating cells

NK cells

Name the cells that attack parasites

Eicosanoids

What are interferons?

Cytokines that interfere with the spread of intracellular pathogens

What is the function of interferons?

Prevents infection in neighboring cells and triggers NK cells

What is the complement system made of?

30 plasma proteins

What organ releases the complement system proteins?

Proteins are released by the liver in their inactive form.

What is inflammation?

An immediate response to ward off unwanted substances

What are the steps of generating the inflammatory response?

Chemicals released by injured tissues, vascular changes, leukocytes recruited, plasma proteins arrive

What is a fever?

Elevated body temperature due to the release of pyrogens from immune cells

What do pyrogens target in the hypothalamus?

Prostaglandin E2

What are the benefits of a fever?

It inhibits the reproduction of bacteria and viruses, promotes interferon activity, increases adaptive immunity, and accelerates tissue repair.

Why should you not let a high-grade fever run its course?

Because it can cause brain damage, seizures, denaturing proteins, and death

Is the third line of defense innate or adaptive?

Adaptive

How does the third line of defense differ from the first and second?

It has a longer response

Which cells are used for cell-mediated defense?

T-lymphocytes

Which cells are used for antibody-mediated defense?

B-lymphocytes, plasma cells, and antibodies

What are antigens?

Substances that T-lymphocytes or antibodies will bind to

What is the difference between foreign and self antigens?

Foreign differs from the body's own molecules, self is the body's own molecules

What do antigen-presenting cells do?

APCs present to both helper and cytotoxic T cells

What is a major histocompatibility complex (MHC)?

Transmembrane proteins on cells where the antigen attaches

Describe IgG

75-85 percent of antibodies, participates in all antibody actions, crosses the placenta

Describe IgM

Mostly in the blood, responsible for rejection of mismatched transfusions

Describe IgA

Found in areas exposed to the environment, prevents pathogens from getting through the epithelium, protects the respiratory and GI tract

Describe IgD

Antigen-specific B-lymphocyte receptor, recognizes when immature B-lymphocytes are ready for maturation

Describe IgE

Formed in response to parasites and allergic reactions, causes release of products from basophils and mast cells, attracts eosinophils

What is neutralization?

Antibody covers the pathogen and makes it ineffective at establishing an infection

What is agglutination?

Antibody crosslinks foreign cells together and causes clumping

What is precipitation?

Antibody forms a complex with another antibody and then precipitates out of body fluids

In order to develop immunologic memory, what must happen?

A long-lived army of lymphocytes

What happens the next time you are exposed to the antigen?

Memory cells rapidly contact the antigen and produce a powerful secondary response

What do vaccines contain?

Weak or dead microorganisms or parts of microorganisms

What do vaccines stimulate the immune system to do?

Stimulate the immune system to develop memory B-lymphocytes

What is herd immunity?

Resistance of members within a population to a disease

What makes a disease unable to proliferate?

Low number of infectible people

What is active immunity?

Lymphocyte response to an antigen

What cells are used in cell-mediated active immunity?

T lymphocytes

What cells are used in antibody-mediated active immunity?

B lymphocytes, plasma cells, and antibodies

What is passive immunity?

Immunity obtained from someone else

What are some exposures that lead to passive immunity?

Natural transfer of antibodies from mother to baby through placenta or milk, artificially using serum from one person to another, does not produce memory cells