Question 1

All of the following increase blood vessel permeability EXCEPT

Accepted Answer

Lysozymes are not known to increase blood vessel permeability.

Question 2

Phagocytes utilize all of the following to optimize interaction with (getting to and getting hold of) microorganisms EXCEPT

Accepted Answer

Lysozyme is not used to optimize interaction with microorganisms but rather to destroy them once they have been engulfed by a phagocyte. A, B, C, and D are all mechanisms that phagocytes use to get to and hold onto microorganisms.

Question 3

Which of the following exhibits the highest phagocytic activity?

Accepted Answer

C

Question 4

TLRs attach to all of the following EXCEPT

Accepted Answer

TLRs (Toll-like receptors) attach to a variety of pathogen-associated molecular patterns (PAMPs) including LPS, peptidoglycan, flagellin, viral RNA, and bacterial DNA. However, they do not attach to AMPs (antimicrobial peptides) which are part of the innate immune system and produced by host cells to fight against microbial infections.

Question 5

The function of the ʺciliary escalatorʺ is to

Accepted Answer

The ciliary escalator is a mechanism present in the respiratory system that traps inhaled dust and microorganisms in mucus and propels it away from the lower respiratory tract, therefore preventing them from entering the lungs. Option A is incorrect because the ciliary escalator is present in the respiratory tract, not the gastrointestinal tract. Option B is incorrect because it does not trap the particles and instead propels them towards the mouth. Option D is also incorrect because it refers to the wrong part of the body. Option E is partially correct, but it does not mention the crucial function of propelling the mucus away from the lower respiratory tract.

Question 6

Which of the following statements about fixed macrophages is FALSE?

Accepted Answer

Fixed macrophages do not develop from neutrophils. They are cells of the mononuclear phagocytic system that are found in certain tissues and organs, where they gather at sites of infection as mature monocytes.

Question 7

The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway after the point in the cascade where the activation of takes place.

Accepted Answer

The activation of C3 is the point in the complement protein cascade where the pathways converge. After C3 is activated, the rest of the complement protein cascade is the same for the classical, alternative, and lectin pathways. Therefore, the correct answer is D.

Question 8

A differential cell count is used to determine each of the following EXCEPT

Accepted Answer

A differential cell count only looks at the types of white blood cells present in a blood sample, not red blood cells. It can be used to diagnose leukopenia (low white blood cell count) or leukocytosis (high white blood cell count) by analyzing the relative proportions of different types of white blood cells. It can also provide a total count of white blood cells.

Question 9

Margination refers to

Accepted Answer

Margination refers to the adherence of phagocytes to the lining of blood vessels, specifically the walls of capillaries. This is a necessary step for phagocytes to enter tissues and combat infection.

Question 10

The swelling associated with inflammation decreases when the fluid

Accepted Answer

The answer of The swelling associated with inflammation decreases when...

Question 11

Which of the following is an effect of opsonization?

Accepted Answer

Opsonization enhances the adherence of phagocytes to microorganisms by coating them with opsonins, such as antibodies or complement proteins. This increased adherence promotes more efficient phagocytosis of the microorganisms.

Question 12

Each of the following provides protection from phagocytic digestion EXCEPT

Accepted Answer

Formation of phagolysosomes is a step in phagocytic digestion where the phagosome fuses with a lysosome to form a phagolysosome, which contains enzymes that can digest bacteria. Therefore, measures that prevent the formation of phagolysosomes would not provide protection against phagocytic digestion. Choices A, B, D, and E can all provide protection against phagocytic digestion by various mechanisms.

Question 13

Each of the following is an effect of complement activation EXCEPT

Accepted Answer

Complement activation can lead to increased blood vessel permeability, opsonization, bacterial cell lysis, and increased phagocytic activity. However, it does not interfere with viral replication, so choice C is the correct answer.

Question 14

Innate immunity

Accepted Answer

Innate immunity is present at birth and is nonspecific, meaning it responds to a wide range of pathogens without the need for prior exposure or memory. It is the first line of defense against pathogens and provides a rapid response. It is different from adaptive immunity, which involves T and B lymphocytes and has a memory component. Innate immunity does not provide increased susceptibility to disease.

Question 15

Which of the following is found normally in serum?

Accepted Answer

Complement is a group of serum proteins that play a role in immune defense by enhancing phagocytosis, triggering inflammation, and directly attacking invading pathogens. The other options are not typically found in serum.

Question 16

A child falls and suffers a deep cut on her leg. The cut went through her skin and she is bleeding. Which of the following defense mechanisms will participate in eliminating contaminating microbes?

Accepted Answer

The answer of A child falls and suffers a deep...

Question 17

All of the following protect the skin and mucous membranes from infection EXCEPT

Accepted Answer

HCl is a strong acid that is found in the stomach and aids in the digestion of food. It does not directly protect the skin and mucous membranes from infection.

Question 18

Which of the following statements is TRUE?

Accepted Answer

The answer of Which of the following statements is TRUE?
...

Question 19

The antimicrobial effects of AMPs include all of the following EXCEPT

Accepted Answer

AMPs do not inhibit phagocytosis, which is the process by which immune cells engulf and destroy invading microorganisms. AMPs instead enhance phagocytosis by recruiting immune cells to the site of infection.

Question 20

Normal microbiota provide protection from infection in each of the following ways EXCEPT

Accepted Answer

Normal microbiota do not produce lysozyme, which is an antibacterial enzyme found in tears, saliva, and mucus that helps to break down bacterial cell walls. However, normal microbiota do produce their own antibacterial chemicals and compete with pathogens for nutrients. They can also alter the chemical and physical environment, making it less suitable for the growth of nonresident bacteria.

Quiz 29: Innate Immunity: Nonspecific Defenses of the Host