Superantigens produce intense immune responses by stimulating lymphocytes to produce ___.

Superantigens produce intense immune responses by stimulating lymphocytes to produce ___.

A. endotoxins
B. exotoxins
C. cytokines
D. leukocidins
E. interferons


Answer: C. cytokines

Which non-specific defense mechanism is mismatched with its associated body structure or body fluid?

Which non-specific defense mechanism is mismatched with its associated body structure or body fluid? 

A) lysozyme — tears and saliva
B) mucociliary escalator — intestines
C) very acidic pH— stomach
D) keratin and tightly packed cells — skin
E) cerumen and sebum — ear



Answer: B) mucociliary escalator — intestines

Lysozyme and the antibiotic penicillin have similar mechanisms of action in that they both cause damage to the bacterial

Lysozyme and the antibiotic penicillin have similar mechanisms of action in that they both cause damage to the bacterial 

A) cell membrane.
B) capsule.
C) cell wall.
D) DNA.
E) ribosomes.


Answer: C) cell wall.

Which of the following statements about the classical pathway of complement activation is FALSE?

Which of the following statements about the classical pathway of complement activation is FALSE?

A) C1 is the first protein activated in the classical pathway.
B) The C1 protein complex is initiated by antigenantibody complexes.
C) C3 is not involved in the classical pathway.
D) Cleaved fragments of some of the proteins act to increase inflammation.
E) C3b causes opsonization.


Answer: C) C3 is not involved in the classical pathway.

Several inherited deficiencies in the complement system occur in humans. Which of the following would be the MOST severe?

Several inherited deficiencies in the complement system occur in humans. Which of the following would be the MOST severe?

A) deficiency of C3
B) deficiency of C5
C) deficiency of C6
D) deficiency of C7
E) deficiency of C8


Answer: A) deficiency of C3

All of the following are components of the inflammatory process EXCEPT

All of the following are components of the inflammatory process EXCEPT

A) dilation of blood vessels.
B) release of histamines and prostaglandins.
C) chemotaxis.
D) diapedesis.
E) antibody synthesis.


Answer: D) diapedesis.

The lectin pathway for complement action is initiated by

The lectin pathway for complement action is initiated by

A) mannose on host membranes.
B) mannose on the surface of microbes.
C) lectins of the microbe.
D) gram-negative cell walls.
E) gram-positive cell walls.


Answer: B) mannose on the surface of microbes.

All of the following occur during inflammation. What is the first step?

All of the following occur during inflammation. What is the first step?

A) diapedesis
B) margination
C) phagocyte migration
D) repair
E) vasodilation


Answer: E) vasodilation

All of the following are iron-binding proteins found in humans EXCEPT

All of the following are iron-binding proteins found in humans EXCEPT 

A) lactoferrin.
B) transferrin.
C) hemoglobin.
D) siderophorin.
E) ferritin.


Answer: D) siderophorin.

All of the following pertain to fever EXCEPT that it

All of the following pertain to fever EXCEPT that it

A) accelerates microbial growth by increasing iron absorption from the digestive tract.
B) stimulates T lymphocyte activity.
C) is caused by interleukin-1 and TNF-alpha coming into contact with the hypothalamus.
D) intensifies the effect of antiviral interferons.
E) can be initiated by specific types of pathogens.


Answer: A) accelerates microbial growth by increasing iron absorption from the digestive tract.

Macrophages arise from which of the following?

Macrophages arise from which of the following?

A) basophils
B) eosinophils
C) lymphocytes
D) monocytes
E) neutrophils


Answer: D) monocytes

Which of the following is involved in resistance to parasitic helminths?

Which of the following is involved in resistance to parasitic helminths?

A) basophils
B) eosinophils
C) lymphocytes
D) monocytes
E) neutrophils


Answer: B) eosinophils

All of the following are true regarding NK cells EXCEPT

All of the following are true regarding NK cells EXCEPT 

A) they are a type of lymphocyte.
B) they are found in tissues of the lymphatic system.
C) they have the ability to kill infected body cells and some tumor cells.
D) they destroy infected body cells by phagocytosis.
E) they release toxic substances that cause cell lysis or apoptosis.


Answer: D) they destroy infected body cells by phagocytosis.

Activation of C5C9 results in

Activation of C5C9 results in

A) activation of C3.
B) fixation of complement.
C) lysis of microbial cells.
D) phagocytosis.
E) inflammation.


Answer: C) lysis of microbial cells.

After ingesting a pathogen, lysosomal enzymes produce all of the following EXCEPT

After ingesting a pathogen, lysosomal enzymes produce all of the following EXCEPT

A) complement.
B) O2-.
C) H2O2.
D) OH·.
E) HOCl.


Answer: A) complement.

Innate immunity includes all of the following EXCEPT

Innate immunity includes all of the following EXCEPT

A) phagocytosis.
B) inflammation.
C) production of antibody.
D) production of interferon.
E) activation of complement.


Answer: C) production of antibody.

Neutrophils with defective lysosomes are unable to

Neutrophils with defective lysosomes are unable to

A) undergo chemotaxis.
B) migrate.
C) produce toxic oxygen products.
D) attach to microorganisms and other foreign material.
E) engulf microorganisms and other foreign material.


Answer: C) produce toxic oxygen products.

Activation of C3a results in

Activation of C3a results in

A) acute inflammation.
B) increased blood vessel permeability.
C) opsonization.
D) attraction of phagocytes.
E) cell lysis.


Answer: A) acute inflammation.

The classical pathway for complement activation is initiated by

The classical pathway for complement activation is initiated by

A) lipid-carbohydrate complexes and C3.
B) C5C9.
C) antigenantibody reactions.
D) factors released from phagocytes.
E) factors released from damaged tissues.


Answer: C) antigenantibody reactions.

The alternative pathway for complement activation is initiated by

The alternative pathway for complement activation is initiated by

A) lipid-carbohydrate complexes and C3.
B) C5C9.
C) antigenantibody reactions.
D) factors released from phagocytes.
E) factors released from damaged tissues.


Answer: A) lipid-carbohydrate complexes and C3.