Question 1

A patient has elevated neutrophils and monocytes with normal levels of basophils, eosinophils, and lymphocytes.Which of the following is the most likely cause of these test results?

Accepted Answer

Elevated neutrophils and monocytes are indicative of an ongoing bacterial infection. Basophil, eosinophil, and lymphocyte levels would typically increase in response to a viral or allergic reaction. Fungal infections and autoimmune reactions may also result in elevated white blood cell levels, but the pattern of neutrophilia and monocytosis is more suggestive of a bacterial infection.

Question 2

Immunoglobulins that are the first antibodies to be produced in response to infection are

Accepted Answer

IgM is the first antibody to be produced in response to an infection. It is a pentamer with 10 antigen binding sites, which makes it very efficient at binding to pathogens and initiating the immune response.

Question 3

Match the cell type with its description.
-These are the most abundant leukocyte; they are formed in the bone marrow.

Accepted Answer

Neutrophils are the most abundant type of leukocyte, making up around 60-70% of all leukocytes in the blood. They are formed in the bone marrow and play a critical role in the immune response to bacterial infections.

Question 4

A person's blood type is determined by

Accepted Answer

A person's blood type is determined by the presence or absence of specific glycoprotein molecules on their cell membrane. The four main blood types are A, B, AB, and O, which are determined based on the presence or absence of the A and B glycoproteins on the red blood cell membrane. The presence of both A and B glycoproteins results in blood type AB, while the absence of both results in blood type O.

Question 5

Immunoglobulins that are found on the surface of B lymphocytes and may play a role in regulation of the humoral immune response are

Accepted Answer

IgD is found on the surface of B lymphocytes and may play a role in regulating the humoral immune response by helping to activate B cells. It can also function as an antigen receptor on B cells, but its exact role in immune regulation is still being studied.

Question 6

Match the type of immunity to its description.
-present at birth

Accepted Answer

Nonspecific immunity (also known as innate immunity) is present at birth and provides general protection against a wide range of pathogens without specificity for a particular pathogen. Specific immunity (also known as adaptive immunity), on the other hand, is acquired over time and provides targeted protection against specific pathogens.

Question 7

Class II MHC molecules are found

Accepted Answer

Class II MHC molecules are primarily found on antigen-presenting cells such as lymphocytes (specifically B cells) and macrophages, as well as dendritic cells, which play a key role in the immune response by presenting antigens to T cells.

Question 8

Match the cell type with its description.
-Precursors of macrophages, these cells are relatively rare in blood because they are actually in transit to some other site.

Accepted Answer

Monocytes are the precursors of macrophages and are relatively rare in blood because they are actually in transit to some other site.

Question 9

Match the cell type with its description.
-These cells are related to mast cells, and both release chemical mediators such as histamine and heparin, which aid in the immune response.

Accepted Answer

Basophils are the cells that are related to mast cells and release chemical mediators such as histamine and heparin, which aid in the immune response.

Question 10

When an antigen complex is bound to a Class I MHC molecule, it can stimulate a

Accepted Answer

When an antigen complex is bound to a Class I MHC molecule, it can stimulate cytotoxic T cells. Cytotoxic T cells recognize the antigen presented on the Class I MHC molecule and initiate a response to kill infected or abnormal cells that display this antigen. B cells, plasma cells, helper T cells, and NK cells do not interact with Class I MHC molecules.

Question 11

Match the cell type with its description.
-Cytotoxic, these cells are associated with allergic reactions and parasitic infestations.Usually these cells are less than 3% of the leukocyte population, and only live up to 12 hours.

Accepted Answer

Eosinophils are associated with allergic reactions and parasitic infestations. They release cytotoxic granules that destroy parasites or allergenic substances. They make up less than 3% of the leukocyte population and have a short lifespan of around 12 hours. Lymphocytes, neutrophils, monocytes, and basophils are not specifically associated with allergic reactions and parasitic infestations.

Question 12

In order for a lymphocyte to respond to an antigen, the antigen must

Accepted Answer

In order for a lymphocyte to respond to an antigen, the antigen must bind to specific receptors on the lymphocyte membrane. These receptors, known as B-cell receptors (BCRs) and T-cell receptors (TCRs), are highly specific and can only bind to certain antigens. Once the antigen binds to the receptor, a series of signaling events takes place that ultimately leads to the activation and proliferation of the lymphocyte.

Question 13

A person with type A blood has

Accepted Answer

A person with type A blood has B antibodies in their plasma, which would react against type B antigens.

Question 14

The specificity of an antibody is determined by

Accepted Answer

The variable region, also known as the hypervariable region, is responsible for determining the specificity of an antibody by binding to antigenic determinants on the target molecule. The fixed segment and antibody class do not affect specificity, and size alone does not determine specificity.

Question 15

Immunoglobulins that are primarily found in glandular secretions are

Accepted Answer

Immunoglobulins primarily found in glandular secretions are referred to as secretory immunoglobulins or sIg. These are predominantly IgA antibodies and are found in mucosal surfaces, tears, saliva, breast milk, and other body secretions. IgA plays an important role in preventing infections by neutralizing pathogens and preventing them from adhering to epithelial surfaces.

Question 16

Inappropriate or excessive immune responses to antigens are

Accepted Answer

Inappropriate or excessive immune responses to antigens are commonly seen in allergies, where the immune system overreacts to allergens like pollen or certain food items. Immunodeficiency diseases refer to weakened immune responses to foreign substances, autoimmune diseases involve the immune system attacking the body's own tissues, and stress does not directly cause inappropriate immune responses. While age can impact immune function, it is not necessarily correlated with increased incidence of inappropriate immune responses.

Question 17

Match the cell type with its description.
-Estimated to reach populations of one trillion in normal adults, most of these cells reside in the lymphoid tissues of the body.These cells look quite similar to one another under the microscope, yet function very differently.

Accepted Answer

The estimated population of one trillion cells and the fact that they reside in lymphoid tissues indicate that the cell type being referred to is lymphocytes. Lymphocytes are a type of white blood cell that plays a crucial role in the immune system and can be found in lymphoid tissue such as the spleen, lymph nodes, and thymus. While lymphocytes look quite similar under the microscope, they can function differently based on the types of antigens they encounter and the immune response required.

Question 18

A patient has elevated eosinophils and monocytes but normal levels of neutrophils, basophils, and lymphocytes.Which of the following could be causing those levels?

Accepted Answer

Elevated eosinophils and monocytes are commonly seen in chronic parasitic infections. Normal levels of neutrophils, basophils, and lymphocytes suggest that there is no acute infection or severe allergic reaction. Chronic bacterial infections may also cause elevated monocytes, but it is less likely to cause elevated eosinophils. Viral infections typically cause a decrease in eosinophils.

Question 19

A patient with hay fever symptoms that have been going on for a couple weeks comes to your office to be treated for his hay fever.If a white blood cell differential count was performed, which leukocytes would likely be elevated?

Accepted Answer

Hay fever, or allergic rhinitis, is characterized by an allergic response to airborne substances such as pollen. This allergic response typically involves the elevation of eosinophils, which play a key role in allergic reactions. Basophils are also involved in allergic responses due to their ability to release histamine. Monocytes can be involved in the immune response more broadly.

Question 20

Match the type of immunity to its description.
-Secreted lysozyme kills bacteria.

Accepted Answer

Secreted lysozyme is part of the innate or nonspecific immunity, which includes physical and chemical barriers, as well as cellular and soluble components that can recognize and eliminate a wide range of pathogens without requiring previous exposure or memory. In contrast, the adaptive or specific immunity involves the production of antibodies and T cells that are tailored to target specific antigens and can provide long-lasting protection and memory against recurrent infections.

Quiz 24: The Immune System

A patient has elevated neutrophils and monocytes with normal levels of basophils, eosinophils, and lymphocytes.Which of the following is the most likely cause of these test results?

Immunoglobulins that are the first antibodies to be produced in response to infection are

Match the cell type with its description. -These are the most abundant leukocyte; they are formed in the bone marrow.

A person's blood type is determined by

Immunoglobulins that are found on the surface of B lymphocytes and may play a role in regulation of the humoral immune response are

Match the type of immunity to its description. -present at birth

Class II MHC molecules are found

Match the cell type with its description. -Precursors of macrophages, these cells are relatively rare in blood because they are actually in transit to some other site.

Match the cell type with its description. -These cells are related to mast cells, and both release chemical mediators such as histamine and heparin, which aid in the immune response.