Human Anatomy and Physiology : Systems Physiology
Study concepts, example questions & explanations for Human Anatomy and Physiology
All Human Anatomy and Physiology Resources
Example Questions
Example Question #1 : Help With Proteins And Signals Of Adaptive Immunity
The human immune system is organized along two broad arms: innate immunity and adaptive immunity. The differences between these two approaches to immunity are not always black and white, but can be described in general terms with regard to immunological memory. Adaptive immunity displays this type of memory, and mounts a more intense response to pathogens upon second and subsequent exposures.
Within adaptive immunity, the system is further divided into humoral immunity and cell-mediated immunity. We can say that antibodies are the primary mediators of the former, while CD8 T-cell based cytotoxicity is the mediator of the latter.
CD4 T-cells, unlike their CD8 counterparts, are involved in both the humoral and cell-mediated arms of adaptive immunity. These CD4 cells drive isotype switching, a process that changes the types of antibodies produced after initial exposure to a pathogen to increase their molecular affinity. Additionally, CD4 cells promote the activity of macrophages to directly digest invading pathogens.
Which of the following surface proteins is most likely to be used as a marker to distinguish T-lymphocytes from B-lymphocytes?
CD28
CD5
CD19
CD20
CD21
CD28
The CD family of surface proteins (short for cluster of differentiation) is best understood as a set of nametags to distinguish one set of cells from another. CD28 is the most commonly used marker for T-cells, as it is unique to this cell type. In contrast, B-cells use a number of other unique markers, including CD20 and CD21, among others.
CD5 is used to distinguish chronic lymphocytic leukemia from other leukemic states.
Example Question #11 : Immune Physiology
The human immune system is organized along two broad arms: innate immunity and adaptive immunity. The differences between these two approaches to immunity are not always black and white, but can be described in general terms with regard to immunological memory. Adaptive immunity displays this type of memory, and mounts a more intense response to pathogens upon second and subsequent exposures.
Within adaptive immunity, the system is further divided into humoral immunity and cell-mediated immunity. We can say that antibodies are the primary mediators of the former, while CD8 T-cell based cytotoxicity is the mediator of the latter.
CD4 T-cells, unlike their CD8 counterparts, are involved in both the humoral and cell-mediated arms of adaptive immunity. These CD4 cells drive isotype switching, a process that changes the types of antibodies produced after initial exposure to a pathogen to increase their molecular affinity. Additionally, CD4 cells promote the activity of macrophages to directly digest invading pathogens.
A team of physicians is preparing a patient for a bone marrow transplant. To prevent graft-versus-host disease, where the transplanted T-cells attack the host into which they have been introduced, the physicians make sure that the donor and host have a matching human leukocyte antigen (HLA) type.
Which HLA gene product interacts with receptors on CD8 T-cells most avidly?
Major histocompatibility complex II
CD8
B7
CD5
Major histocompatibility complex I
Major histocompatibility complex I
The protein MHC I is present on the surface of all nucleated cells, and provides a means for cytotoxic CD8 T-cells to exert cell killing on any nucleated cell that becomes infected with a pathogen.
MHC II is a related protein, that is only present on antigen-presenting cells (APC). These antigen-presenting cells must interact with CD4 T-cells. As a result, we can make the generalization that CD4 T-cells interact with MHC II, restricted in expression to APCs, and CD8 T-cells interact with MHC I with far broader expression.
Example Question #3 : Help With Proteins And Signals Of Adaptive Immunity
The human immune system is organized along two broad arms: innate immunity and adaptive immunity. The differences between these two approaches to immunity are not always black and white, but can be described in general terms with regard to immunological memory. Adaptive immunity displays this type of memory, and mounts a more intense response to pathogens upon second and subsequent exposures.
Within adaptive immunity, the system is further divided into humoral immunity and cell-mediated immunity. We can say that antibodies are the primary mediators of the former, while CD8 T-cell based cytotoxicity is the mediator of the latter.
CD4 T-cells, unlike their CD8 counterparts, are involved in both the humoral and cell-mediated arms of adaptive immunity. These CD4 cells drive isotype switching, a process that changes the types of antibodies produced after initial exposure to a pathogen to increase their molecular affinity. Additionally, CD4 cells promote the activity of macrophages to directly digest invading pathogens.
Patients with clear cell carcinoma of the kidney often undergo therapy that uses an inflammatory cytokine to upregulate T-cell activity. Which of the following cytokines is most likely used as a treatmnt for clear cell carcinoma?
IL-5
IL-3
Interferon
IL-2
IL-8
IL-2
IL-2 is the third signal that activates T-cell activity. T-cells are initially activated by MHC/T-cell receptor binding, and then the second B7 signal further primes activity. After these two signals, the T-cell produces its own IL-2, which acts in an autocrine fashion to further accelerate T-cell proliferation.
Example Question #4 : Help With Proteins And Signals Of Adaptive Immunity
The human immune system is organized along two broad arms: innate immunity and adaptive immunity. The differences between these two approaches to immunity are not always black and white, but can be described in general terms with regard to immunological memory. Adaptive immunity displays this type of memory, and mounts a more intense response to pathogens upon second and subsequent exposures.
Within adaptive immunity, the system is further divided into humoral immunity and cell-mediated immunity. We can say that antibodies are the primary mediators of the former, while CD8 T-cell based cytotoxicity is the mediator of the latter.
CD4 T-cells, unlike their CD8 counterparts, are involved in both the humoral and cell-mediated arms of adaptive immunity. These CD4 cells drive isotype switching, a process that changes the types of antibodies produced after initial exposure to a pathogen to increase their molecular affinity. Additionally, CD4 cells promote the activity of macrophages to directly digest invading pathogens.
A scientist develops a protein that is able to interrupt the normal function of CD8 T-cells, preventing them from actively killing target cells. Except for actively killing targets, T-cells behave, physically bind to target cells, and develop normally after treatment with this protein. Which protein/receptor pair interaction on CD8 T-cells is most likley being interrupted by this protein?
IL-2/IL-2 receptor
CD-19/CD-19 receptor
Fas/Fas ligand
T-cell receptor/major hisotcompatibility complex I
CD28/B7
Fas/Fas ligand
The interaction of Fas and Fas ligand is the most direct option among these choices that drives cell killing. The remainder of the options are either not relevant to T-cells, or are involved in simple binding or development. The interaction of Fas and its ligand actually drives cell death.
Example Question #421 : Systems Physiology
Which of the following attaches directly to pathogens to mark them for destruction?
Plasma cells
B-cells
Antibodies
T-cells
Macrophages
Antibodies
Antibodies are produced by plasma cells (mature B-cells) with specific binding affinity for surface proteins that have been presented by antigen-presenting cells, like dendritic cells and macrophages. Once the plasma cell is stimulated by the presence of the specific antigen, it increases production of its antibody. These antibodies enter the blood and bind the antigen molecules on the surface of the pathogen cell. Cytotoxic T-cells and cytokines can then interact with the antibodies to initiate lysis of the infected cell or pathogen.
Example Question #422 : Systems Physiology
Which of the following statements is true?
Memory T-cells release antibodies in the event of infection by a previously encountered pathogen
B-lymphocytes have antibodies that attach to presented antigens
A B-lymphocyte will release different antibodies until one of them attaches to an antigen
An antibody can attach to multiple antigens
B-lymphocytes have antibodies that attach to presented antigens
It helps to think of antigens and antibodies like a lock and key: they are highly specific for one another. B-lymphocytes create only one type of antibody. When this antibody attaches to an antigen presented by a macrophage or antigen-presenting cell, the B-lymphocyte will differentiate with the help of a helper T-cell. The result is replication of the B-lymphocyte to produce more of the same antibody from plasma cells and generate memory B-cells to easily respond in the event of a second infection by the pathogen.
Example Question #14 : Immune Physiology
The human immune system is organized along two broad arms: innate immunity and adaptive immunity. The differences between these two approaches to immunity are not always black and white, but can be described in general terms with regard to immunological memory. Adaptive immunity displays this type of memory, and mounts a more intense response to pathogens upon second and subsequent exposures.
Within adaptive immunity, the system is further divided into humoral immunity and cell-mediated immunity. We can say that antibodies are the primary mediators of the former, while CD8 T-cell based cytotoxicity is the mediator of the latter.
CD4 T-cells, unlike their CD8 counterparts, are involved in both the humoral and cell-mediated arms of adaptive immunity. These CD4 cells drive isotype switching, a process that changes the types of antibodies produced after initial exposure to a pathogen to increase their molecular affinity. Additionally, CD4 cells promote the activity of macrophages to directly digest invading pathogens.
After isotype switching facilitates the production of new serum antibody types by B-cells, an experiment shows that antibodies bind more tightly to pathogens. The researcher conducting the experiment concludes that these new antibodies are more efficient at interrupting infection than were the antibodies produced immediately following initial exposure to the pathogen. Which of the following is the most likely?
IgA was produced immediately after initial pathogen exposure, while IgG was produced after isotype switching
IgM was produced immediately after initial pathogen exposure, while IgA was produced after isotype switching
IgA was produced immediately after initial pathogen exposure, while IgM was produced after isotype switching
IgM was produced immediately after initial pathogen exposure, while IgG was produced after isotype switching
IgG was produced immediately after initial pathogen exposure, while IgM was produced after isotype switching
IgM was produced immediately after initial pathogen exposure, while IgG was produced after isotype switching
The question specifies that the antibodies in question are serum antibodies, while IgA is primarily an antibody type secreted into luminal environments. As a result, we can conclude that IgA is not likely to be involved at all in this experiment. Beyond this, you must know that IgM is the type of antibody that is produced upon initial pathogen exposure. After CD4 cells facilitate isotype switching, IgG is produced and demonstrates more robust binding.
Example Question #3 : Help With Antigens, Antibodies, And Mh Cs
The human immune system is organized along two broad arms: innate immunity and adaptive immunity. The differences between these two approaches to immunity are not always black and white, but can be described in general terms with regard to immunological memory. Adaptive immunity displays this type of memory, and mounts a more intense response to pathogens upon second and subsequent exposures.
Within adaptive immunity, the system is further divided into humoral immunity and cell-mediated immunity. We can say that antibodies are the primary mediators of the former, while CD8 T-cell based cytotoxicity is the mediator of the latter.
CD4 T-cells, unlike their CD8 counterparts, are involved in both the humoral and cell-mediated arms of adaptive immunity. These CD4 cells drive isotype switching, a process that changes the types of antibodies produced after initial exposure to a pathogen to increase their molecular affinity. Additionally, CD4 cells promote the activity of macrophages to directly digest invading pathogens.
A scientist is conducting an experiment with a bacterial cell that stimulates an antibody response in mice. The scientist is able to isolate the particular region of the bacterial cell that generates the response and binds to the antibody. This portion of the bacterial cell is best described as the __________.
heavy chain
variable region
constant region
epitope
light chain
epitope
The epitope is the region of a target cell to which an antibody binds. The remaining choices are all structural regions of the antibody itself, as opposed to the target cells to which an antibody binds.
Example Question #2 : Help With Antigens, Antibodies, And Mh Cs
Which antibody is able to cross the placenta?
IgM
IgE
IgA
IgD
IgG
IgG
IgG is the only class of immunoglobulin that is able to cross the placenta. This is important as this immunoglobulin is able to provide passive immunity to the unborn fetus
Example Question #4 : Help With Antigens, Antibodies, And Mh Cs
MHC I is found on which cell types?
B cells only
All nucleated cells
Phagocytic cells only
Antigen presenting cells only
None of the other answers
All nucleated cells
MHC I is found on all nucleated cells and presents antigens to cytotoxic T lymphocytes. These cytotoxic T cells contain CD8 receptors, which binds to MHC I. MHC II cells are found on B-lymphocytes and antigen presenting cells only. MHC II presents antigens to helper T cells, which contain CD4 receptors.
Certified Tutor
All Human Anatomy and Physiology Resources
