Lymphatic System Flashcards
(31 cards)
What is the first line of defense within the innate immunity system?
Barrier such as the skin or muscous membranes
- prevents entry to body tissue physically
Name the two arms of the adaptive defense system, and relate each to a
specific lymphocyte type (B or T cell).
It splits into humoral (B-cells) and cell-mediated immunity (T-cells)
Define humoral immunity.
Defence in extracellular fluids
results in the production of antibodies (immunoglobins)
State the role of plasma cells.
To secrete antibodies
What is a lymphocyte?
White blood cell
Explain the function(s) of antibodies
Antibodies are proteins produced by sensitised B cells or plasma cells in response to an antigen
Describe the structure of an antibody monomer.
An antibody is composed of 4 polypeptide chains that form a Y shaped molecule
Variable = antigen-binding
Constant = function & class
List the five antibody classes, and describe their specific roles in immunity.
Immunoglobins = IgM, IgA, IgD, IgG, & IgE
Describe several ways in which antibodies act against antigens.
Aggulination, complement fixtation, neutralisation, opsonisation & precipitation
Distinguish the roles of helper, regulatory, and cytotoxic T cells.
Cytotoxic = directly kill foreign or infected cells
Helper T = direct the adaptive immune response and turn on B & T cells (mac)
Regulatory = turn off immune response once foreign material is destroyed
What is the difference between active & passive immunity?
Active = produced by person’s own body during infection/vaccine
Passive = when antibodies by another person is injected into bloodstream e.g. babies
Name the functions of humoral immunity.
Formation of antigen & antibody inactivates the antigen and enhances phagocytosis (op.) by neutrophils by
- neutralisation (toxins, viruses)
-aggulination (cell bound antigens)
- precipitation (cell soluble)
How are antibodies produced?
Antibodies (proteins) are produced from plasma cells in the lymph nodes by activated B cells in response to a specific antigen.
Describe briefly the defense mechanisms that is directly facilitated by antibodies?
Neutralization of pathogens to prevent infection of host cells
Activation of the complement system
Opsonization of pathogens for destruction by phagocytes
What are the two different types of body defences
Adaptive & Innate
What is the function of lymph nodes in the lymphatic system?
To filter and purify lymphatic fluid
In a routine examination, some blood is taken and analysed. The results show a high IgM titer but a lower IgG titer for the mumps virus. This would suggest that the person:
was recently infected with mumps
Specific defenses depend on the activities of
lymphocytes
The first line of cellular defence against pathogens is
phagocytes
Which one of the following statements most accurately describes innate immunity?
Cell surface molecules on bacteria trigger phagocytosis and the inflammatory response, key features of innate immunity
Antibodies recognize antigens
via their hypervariable regions
Which of the following will increase lymph flow?
elevated cardiovascular capillary pressure
Activation of a cytotoxic T cell results in the formation of a clone of cytotoxic T cells that consist of
both active cytotoxic T cells and memory cytotoxic T cells
What is adaptive immunity characterised by??
Memory and specificity
