Human Anatomy and Physiology : Systems Physiology
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Example Questions
Example Question #2 : Help With Proteins And Signals Of Innate 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.
Neoplasms of the immune system are often classified by which surface proteins are present on rapidly dividing cells. A physician is evaluating a patient with a B-cell lymphoma. Which of the following normally present surface proteins is most likley used as a marker for a B-cell lymphoma?
CD28
CD42
CD19
CD42L
CD56
CD19
CD19, CD20, and CD21 are all normal B-cell surface proteins and can thus be used as markers for B-cell lymphomas.
Example Question #3 : Help With Proteins And Signals Of Innate 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.
The innate immune system is usually the first system to respond to invading pathogens. As part of its initial response, innate immune cells must leave the circulation and enter the peripheral tissues where pathogens are present. The process by which immune cells leave the circulation is first initiated by adhesion proteins that make cells stick to the side of blood vessel walls, before they cross the vessel and enter the periphery. Which of the following proteins is most likely involved in mediating adhesion?
ICAM-1
IFN-beta
IFN-alpha
IL-4
TNF-alpha
ICAM-1
All of these options, except ICAM-1, are soluble mediators that drive different elements of immune response. These soluble mediators are more like cytokines than is ICAM-1, which is a structural adhesin that facilitates polymorphonuclear cells sticking to the side of blood vessels. This neutrophil margination is the first step toward diapedesis, or the crossing of the cells into the peripheral tissue to carry out their function.
Example Question #52 : Immune Physiology
Which of the following is overexpressed during rheumatoid arthritis?
Histamine
TNF-alpha
IL-2
Bradykinin
TNF-alpha
TNF-alpha is routinely involved in inflammation and helps regulate the response of the cells of the innate immune system. Overexpression of TNF-alpha can lead to overstimulation of these immune cells, resulting in the autoimmune disorder of rheumatoid arthritis.
Example Question #2 : Help With Proteins And Signals Of Innate Immunity
Which of the following is not a direct result of complement activation?
Inflammation
Attraction of neutrophils and macrophages to the site of infection
Formation of the membrane-attack complex
Enhancement of the ability of phagocytic cells to kill microorganisms
Vasoconstriction
Vasoconstriction
When complement is activated, blood vessels dilate, not constrict. Direct consequences of complement activation include: membrane attack complex forms, dilates blood vessels, attracts neutrophils and macrophages, inflammation, mast cells stimulated, bacteria is made more readily engulfed or opsonized, and antibody-antigen complexes are solubilized.
Example Question #3 : Help With Proteins And Signals Of Innate Immunity
What is the function of a chemokine?
Growth and differentiation of leukocytes
Recruit other immune cells to the sight of infection
Antiviral
Activates inflammatory response
Kill tumor cells
Recruit other immune cells to the sight of infection
Chemokines are a type of cytokine (signaling molecule) that recruits other cells to the sight of an infection. Interferons have antiviral properties and activate the inflammatory response, interleukins are responsible for growth and differentiation of leukocytes, and tumor necrosis factor is responsible for mediating many immune functions and facilitates the destruction of tumor cells.
Example Question #461 : Systems Physiology
Leukocytopenia is defined as which of the following?
Abnormally low white blood cell counts
Abnormally high white blood cell counts
Abnormally low platelet counts
Abnormally low red blood cell counts
Abnormally low white blood cell counts
The suffix "-penia" in medical terminology is used to signify a deficiency. This means that the amount is abnormally low. The prefix "leuko-" can also be found in the word leukocytes, which is another word for white blood cells. As a result, leukocytopenia means abnormally low white blood cell levels.
Erythropenia is a condition in which erythrocyte counts (red blood cells) are low.
Example Question #2 : Help With Other Innate Immunity Physiology
Which of the following is not an example of innate immunity in the body?
Plasma cells
Stomach acid
Neutrophils
Skin
Plasma cells
Innate immunity is a generalized defense system against invading pathogens and foreign materials. In other words, these defenses are already found in the body and do not need to see a pathogen before becoming present. Plasma cells arise from B-lymphocytes, and must interact with an antigen from a pathogen in order to proliferate in the body.
Skin, stomach acid, and granulocytes (such as neutrophils) are constant presences in the body that help defend against pathogens.
Example Question #55 : Immune Physiology
Which of the following does not limit bacterial growth?
Bacterial cell density
Immune response
Increased nutrient availability
Decreased nutrient availability
Increased nutrient availability
Increased nutrient availability would increase bacterial cell growth, while all the other answers decrease ability of bacteria to grow in culture.
Example Question #3 : Help With Other Innate Immunity Physiology
Which of the following is not a part of innate immunity?
Antibodies
Stomach acid
Skin
Saliva
Tears
Antibodies
The immune system consists of two components, the innate (non-specific) and the adaptive (specific) arms. These components work together to prevent infection, clear established infections, and to protect against disease or foreign bodies. The innate (non-specific) system consists of barriers, the complement cascade, and other specialized cells. Barriers include saliva, tears, skin, mucous linings, stomach acid, and "good" gut bacteria (this outcompetes bad bacteria).
Example Question #1 : Circulatory Physiology
Which blood vessel directly feeds blood to the left ventricle before it is pumped out to the rest of the body?
Aorta
No blood vessel directly feeds the left ventricle
Superior vena cava
Pulmonary vein
Inferior vena cava
No blood vessel directly feeds the left ventricle
Blood enters the left ventricle from the left atrium through the mitral valve; no blood vessel directly feeds blood to the left ventricle to be distributed to the rest of the body. The left atrium is directly fed by the pulmonary vein, and the left ventricle empties into the aorta.
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