21. The Immune System

Defensin antimicrobial peptides kill microbes by:

Phagocytes move through capillary walls by squeezing between adjacent endothelial cells, a process known as

(a) Diapedesis

(b) Chemotaxis

(c) Adhesion

(d) Perforation

The process by which neutrophils squeeze through capillary walls in response to inflammatory signals is called:

a. Diapedesis

b. Chemotaxis

c. Margination

d. Opsonization

Interferons are referred to as antiviral proteins. What stimulates their production, and how do they protect uninfected cells? Which cells of the body secrete interferons?

Eileen presents with flu-like symptoms, including fever, chills, and body aches.

You order blood work and find that the number of neutrophils in the blood is greatly elevated. What does this tell you about the likely type of pathogen involved? Explain.

What property of antimicrobial peptide allows them to disrupt bacterial cell surfaces?

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Fever is generated by pyrogens that reset the temperature set point of the hypothalamus to a lower value.

What seven defenses, present at birth, provide the body with the defensive capability known as innate (nonspecific) immunity?

What is complement? How does it cause bacterial lysis? What are some of the other roles of complement?

The most beneficial effect of fever is that it

(a) Inhibits the spread of some bacteria and viruses

(b) Increases the metabolic rate by up to 10 percent

(c) Stimulates the release of pyrogens

(d) Achieves a and b