A&P II, Humoral Immunity (Ch. 9), Unit 2
Terms in this set (29)
How does a lymphocyte exhibit immunocompetence?
A: by being able to recognize their one specific antigen
All lymphocytes must be able to recognize their own antigen in order to be effective. This ability is called immunocompetence.
What is the difference between the primary and the secondary immune response?
A: A primary response results when naive lymphocytes are activated, while a secondary response is a result of activating memory cells.
A primary immune response is initiated when naive lymphocytes are exposed to foreign antigens. Since naive cells are being stimulated, the response is slower to progress than a secondary response in which memory lymphocytes are activated. In addition to being slower than the secondary response, the primary response yields fewer antibodies than a secondary response. Furthermore, primary response antibodies do not bind to antigens as efficiently as the antibodies produced in a secondary response. Lastly, a secondary response tends to last longer than a primary response.
Which mechanism(s) of antibody action result(s) in cell lysis?
A: complement fixation and activation
Complement has the potential to bind antigen by itself (alternative pathway), but it may require an antibody to bind to the antigen first (classical pathway).
What class of antibody acts to clump red blood cells because of a transfusion of mismatched blood?
A: immunoglobin M (IgM)
IgM is the only antibody that forms a pentamer; it is found in circulating plasma. It is responsible for the negative reaction to an incompatible ABO blood type during a transfusion.
In clonal selection of B cells, which substance is responsible for determining which cells will eventually become cloned?
Vaccines provide what type of immunity?
A: artificial active
Artificial immunity is achieved by man-made mechanisms (i.e., immunization). Artificial active immunity is a situation in which the individual made the antibodies after being immunized with an attenuated or dead pathogen.
The primary immune response ________.
has a lag period while B cells proliferate and differentiate into plasma cells
What part of the antibody's structure determines its class?
A: constant (C) region
The constant region, which includes parts of each heavy and light chain, is identical to other molecules in its class but differ between classes.
Select the best description of the negative selection process of lymphocyte maturation.
removal of lymphocytes that react with "self" cells
Without the positive selection process in lymphocyte maturation ________.
T-cells would not be able to properly bind to APC's and therefore not be activated by them
Which immunoglobulin class is attached to the external surface of B cells and acts as an antigen receptor of the B cell?
Which of the areas seen the figure must be occupied by T lymphocytes, at least for a while, but is NOT required for the production of B lymphocytes?
A: the thymus
The thymus and the hormone thymosin are required for the maturation of T lymphocytes.
How many sites on this antibody molecule have potential to bind to a non-self molecule?
Each antigen-binding site has potential to attach to a non-self molecule.
Proliferation of lymphocytes occurs immediately after __________.
Activation after the binding of an antigen leads to proliferation and differentiation.
The antivenom used to treat venomous snake bites is an antibody produced in an animal such as a horse. Suppose these antibodies are injected into a patient who has been bitten by a venomous snake--how would you classify the resulting humoral immunity?
A: passive immunity, artificially acquired
The immunity to venom (usually short lived--the protection ends once the antibodies are naturally degraded by the body) is passive because the patient did not produce the antibodies, and it is artificially acquired since it was injected during a medical process.
Which of the following cells engulf antigens and present fragments of them on their own surfaces for recognition?
Dendritic cells are antigen-presenting cells that engulf antigens and then present fragments of them to their own surfaces, where T cells can recognize them.
How can an antigen cause the formation of more than one antibody?
One antigen may have many different antigenic determinants and may therefore cause the formation of more than one antibody.
Which of the following are antigen-presenting cells (APC)?
A: B cells
B cells can present antigens to T helper cells.
B lymphocytes develop immunocompetence in the ________.
Small molecules that bind with self-proteins to produce antigenic substances are called ________.
What occurs when antibodies block specific sites on viruses or bacterial exotoxins?
The binding of antibody can neutralize the action of viral binding, bacterial toxin release, and other harmful activities of antigen-bearing agents.
Cytotoxic T cell function
Kills cancer cells and virus infected body cells
What cell's absence results in no immune response?
Helper T cell
B cell function
Forms antibody producing cells
Regulatory T cell function
Slows or stops the immune response
Memory cell function
Enables quick and efficient response to secondary exposure to antigen
Adaptive defenses require us to use what molecules that can identify whether a cell is a self or nonself cell?
Antibodies are used to recognize antigens.