LYMPHATIC SYSTEM AND IMMUNITY Flashcards
(24 cards)
state the three functions of the lymphatic system
- drain excess interstitial fluid
- transport lipids
- immune system support
name the cells of lymph nodes
B cells (lymphocytes) T cells (lymphocytes) macrophages (phagocytes)
describe the role of B cells
B cells (lymphocytes) mature in the bone marrow hence “b cells”, their function of lymphocytes in the nodes is to stimulate immune response
describe the role of T cells
T cells (lymphocytes) mature in the thymus hence “t cells” function of lymphocytes in the nodes is to stimulate immune response
describe the role of macrophages
macrophages (phagocytes) in the nodes is to destroy foreign substances through phagocytosis
discuss the implications of treating a fever
because fever has benefits of helping the infection or inflammation routine use of these drugs should be avoided unless
- temp reaches 40 degrees
- there is known heart disease or implants
- fluid and electrolyte imbalance
- danger of febrile convulsions in children
- persons at risk of infection due to low immune system
describe the role of fever in the inflammatory process
raises the temp above the optimal temp for growth of many pathogens so slows rate of bacterial growth
increases the rate of chemical reactions in the body
- the body’s defence mechanisms are faster and duration of the infection shorter
name the 3 lines of defence and classify each as either innate or adaptive
fist line: innate/non-specific
second line: innate/ non-specific
third line: acquired/adaptive
name the cells involved in phagocytosis and briefly describe the function of it
neutrophils: fastest of all white blood cells to respond to tissue damage by bacteria, their numbers increase explosively during bacterial infections, release chemicals (oxidants and bleach) to destroy bacteria
monocytes: leave bloodstream and develop into macrophages, they devour bacteria, fungi, spores, dust, dead body cells and cell debris
state the overall function of inflammation
- destroy the microbe
- prevent the spread
- clear the site
- repair the damaged tissue
name and describe the 3 stages of inflammation
- vasodilation and increased blood vessel permeability
- phagocyte migration to the damaged tissue and phagocytosis of bacteria and cellular debris
- tissue repair
describe cell-mediated immunity
T cells destroy cells that harbor viruses or bacteria and cancer cells and parasites
occurs inside cells
define immunity
immunity is the capacity of the immune system to successfully defend the body against a potentially infectious agent
name the cells involved in adaptive immunity
lymphocytes play an essential role. in adaptive immunity
T lymphocytes
B lymphocytes
name the 2 categories of adaptive immunity
- antibody- mediated immunity
2. cell-mediated immunity
describe antibody-mediated immunity
this response activates B cells that then proliferate and produce
plasma cells which make antibodies that target bacteria and their toxins and prepare them for destruction. Antibodies also target viruses before they enter the body cells
memory cells which persist in the body for months to years and can react with the same antigen again if it enters the body at a later time.
describe the primary and secondary immune response and the importance of the secondary response
primary immune response: is the response of the immune system the first time it is exposed to a particular antigen
the secondary immune response: is due to increased numbers of specific memory cells which are more easily stimulated to produce plasma cells which produce antibodies.
describe an antibody
Y-shaped, globular protein molecules. also known as immunoglobulin (ig)
found in the blood and body fluids like lymph, CSF, urine and mucous secretions.
produced by plasma cells which arose from activated B cells
recognize and bind to specific antigen.
once bound being about removal of the antigen from the body in several different ways and prepare them for destruction.
describe igG antibodies
comprise about 80% of the antibodies in serum
protect against bacteria, neutralise toxins and viruses, trigger complement, make phagocytosis more effective.
(ggeee most of them)
describe igA antibodies
10-15% of antibodies in blood
most common antibody in secretions and on mucus membranes is found in:
mucus, saliva, tears, breast milk
it binds to antigen before they invade tissues and prevent microbes adhering to mucus membranes especially the respiratory system.
describe igM antibodies
5-10% of antibodies
first type to be produced when antigen is encountered
lasts only a short time
very good at clumping antigen, and triggering complement
describe the igE antibodies
time amount only
binds to mast cells and basophils which release histamine when antigens binds to to igE
involved in allergic reactions
play a role in immunity to parasitic infection in gut
briefly describe the 4 functions of antibodies
- enhance phagocytosis: antibodies coat the microbe making it easier for the phagocyte to regonside and ingest the microbe
- activates complement: when the antibody connects to the antigen it changes shape exposing a section of the antibody were complement proteins can bind (complement is activation)
- neutralisation:antibodies bind to and black the attachment sites on the microbe to stop it binding to a host cell
- agglutination: into a large complexes so reduces the number of infectious unit phagocytes have to deal with.
describe the role of major histocompatibility complex (MHC)
to prevent the immune system from attacking our own cells we have proteins on the surface of our cells which identify us as self.
they are unique to a specific individual
these proteins are the major histocompatibility complex (MHC)
all our cells (except RBC) have thousands of MHC protein surface makers built into the cell membrane
