Question 1

Which of the following are the three phases of inflammation?

Accepted Answer

The three phases of inflammation are vascular changes, leukocyte recruitment, and resolution. These phases describe the body's response to injury or infection, starting with changes in blood flow and vessel permeability, followed by the movement of white blood cells to the site of injury, and ending with the resolution of the inflammatory response.

Question 2

Which cell type has a nucleus that appears to have two lobes connected by a thin band, has granules that contain diverse enzymes and antimicrobial toxins, and has mediators that are expelled in response to certain allergens and parasites?

Accepted Answer

Eosinophils have a nucleus that typically appears to have two lobes connected by a thin band. They contain granules filled with enzymes and antimicrobial toxins, and they release mediators in response to allergens and parasites, making them key players in allergic reactions and parasitic infections.

Question 3

Why are leukocytes so central to second- line molecular defenses?

Accepted Answer

Leukocytes, or white blood cells, are central to second-line molecular defenses because they produce various molecules, such as cytokines and interferons, that are crucial for the immune response against pathogens.

Question 4

Which of the following pairs is not an example of a cytokine and its function?

Accepted Answer

Eicosanoids are not cytokines; they are lipid-based molecules that play a role in inflammation and immunity but are not classified as cytokines. Cytokines are proteins, such as interferons, interleukins, tumor necrosis factors, and chemokines, that mediate and regulate immunity, inflammation, and hematopoiesis.

Question 5

Which of the following is an example of a bacterial cell utilizing a siderophore to collect iron?

Accepted Answer

Siderophores are specialized molecules produced by bacteria to sequester iron from the environment, including from host iron-binding proteins. This strategy allows bacteria to survive in iron-limited conditions by effectively "stealing" iron from the host's iron-binding proteins.

Question 6

Which of the following images represents a mast cell that produces granules that act as the initial chemical alarm that recruits neutrophils and other leukocytes to the scene and simultaneously promotes early phases of inflammation?

Accepted Answer

The answer of Which of the following images represents a...

Question 7

Which of the following is not a function of a molecular second line defense?

Accepted Answer

Producing antibodies specific to the bacterial infection is a function of the adaptive immune system, not a second line defense. The second line defense includes innate immune responses such as inflammation, fever, and recruitment of immune cells, but antibody production is part of the third line of defense, or adaptive immunity.

Question 8

What are cytokines?

Accepted Answer

Cytokines are signaling proteins that play a crucial role in cell communication, especially within the immune system, to coordinate the body's response to infection and inflammation.

Question 9

Which of the following describes the classical pathway of complement activation?

Accepted Answer

The classical pathway of complement activation is initiated when antibodies bind to antigens on the surface of a pathogen, leading to the activation of the complement system. This pathway is part of the adaptive immune response.

Question 10

Which of the following is not a main goal of inflammation?

Accepted Answer

Inflammation aims to limit infection spread, recruit immune defenses, and facilitate tissue recovery by delivering oxygen and nutrients. Producing localized heat and swelling to denature bacterial proteins is not a primary goal of inflammation; rather, heat and swelling are byproducts of the inflammatory process.

Question 11

Which of the following is not a way that bacteria can evade complement activation?

Accepted Answer

Bacteria can evade complement activation through various mechanisms such as building a capsule (A), releasing enzymes that break down antibodies (C) or complement proteins (D), and producing proteins that mimic regulators of complement activation (E). However, releasing enzymes that specifically break down lectins (B) is not a recognized mechanism for evading complement activation. Lectins are part of the lectin pathway, one of the pathways that activate the complement system, but bacteria typically do not target lectins directly to evade complement; instead, they focus on broader strategies that impact the complement system as a whole.

Question 12

Where is the iron- binding protein transferrin found?

Accepted Answer

Transferrin is primarily found in blood plasma and extracellular fluids, where it binds and transports iron throughout the body.

Question 13

Which cell type is the largest agranular white blood cell, mature as they leave the circulatory system, and increase cell levels due to chronic infections and inflammation, autoimmune disorders, and certain cancers?

Accepted Answer

Monocytes are the largest type of agranular white blood cells. They mature into macrophages and dendritic cells as they leave the circulatory system and enter body tissues. Their levels increase in response to chronic infections, inflammation, autoimmune disorders, and certain cancers, where they play a role in immune defense and regulation.

Question 14

Chronic inflammation

Accepted Answer

The answer of Chronic inflammation
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Question 15

Which cell type works to prevent our immune system from attacking self and from over- reacting to nonthreatening substances, is abundant in tissues next to body openings, and phagocytizes a broad range of antigens?

Accepted Answer

Dendritic cells play a crucial role in the immune system by presenting antigens to T cells, helping to prevent the immune system from attacking the body's own tissues and from overreacting to nonthreatening substances. They are abundant in tissues that are in contact with the external environment, such as skin and the inner lining of the nose, lungs, stomach, and intestines, where they can capture and process a broad range of antigens for the immune response.

Question 16

Which of the following is not a cardinal sign of inflammation?

Accepted Answer

Fever is considered a systemic effect of inflammation rather than a cardinal local sign. The cardinal signs of local inflammation are swelling, loss of function, pain, and redness.

Question 17

Neisseria gonorrhoeae circumvents our iron- sequestering defenses by

Accepted Answer

Neisseria gonorrhoeae captures human iron-binding proteins like transferrin and lactoferrin, extracting the iron for its own use, thus bypassing the host's iron-sequestering defenses.

Question 18

Which of the following is an outcome of complement activation?

Accepted Answer

Complement activation leads to several key outcomes, including opsonization (marking pathogens for phagocytosis), cytolysis (rupturing of pathogen cell membranes), and inflammation (recruitment of immune cells to the site of infection). These processes help the immune system to identify, target, and eliminate pathogens.

Question 19

Which of the following key chemical mediators in inflammation is not matched to its function?

Accepted Answer

Thromboxanes primarily promote platelet aggregation and vasoconstriction, rather than reducing pain receptor stimulation or reducing fever.

Question 20

Which cell type is a subgroup of lymphocytes, abundant in the liver, and has important roles in innate immune protection against viruses, bacteria, parasites, and even tumor cells?

Accepted Answer

Natural killer (NK) cells are a type of lymphocyte (a subgroup of white blood cells) that play a crucial role in the innate immune system. They are abundant in the liver and are known for their ability to recognize and kill virus-infected cells, bacteria, parasites, and tumor cells without the need for prior activation by specific antigens, distinguishing them from other lymphocytes such as T cells and B cells.

Quiz 11: Innate Immunity