Download Immunology Student Notes File

IV. The Body’s Defense Against Disease
A. Non Specific Defense Mechanisms: Innate Immunity
1. The Skin and Mucus Membrane: External Defenses are Physical barriers
a) Perspiration, tears and saliva contain ____________________ an enzyme that
attacks the cell wall of bacteria
b) ___________________________ destroys proteins in germs by low pH
c) __________________ traps germs
2. Phagocytes and Natural Killers: Internal Defenses
a) ________________________ -long living cells which develop from monocytes
and engulf cells which display antigens (foreign protein patterns)
b) ________________________ -short living phagocytes which usually die after
engulfing a germ
c) __________________________________ -identify and destroy infected body
cells by lysing membranes
3. Antimicrobial Proteins: Internal Defenses
a) __________________________ -inhibits the production of viral proteins
1) Makes cancer cells less likely to metastasize
2) Triggers inflammatory response
3) Attracts macrophages
b) __________________________ -group of about 30 proteins which facilitate
phagocytosis and lysis of infected membranes
4. Inflammatory Response
a) _____________________________________ release __________________
which dilate and increase the permeability of blood vessels
1) Increase blood supply to infected area
2) Causes a leakage of plasma into area
b) Release of _____________________________________ which stimulates the
release of WBC from the bone marrow
c) Chemical signals also attract phagocytes
d) _____________________________ -increase body temperature which
facilitates phagocytosis and inhibits bacterial growth
B. The Immune Response
1. Active Vs Passive Immunity
a) _________________________________ -the body is stimulated to produce its own
antibodies
b) _________________________________ -fetus gets antibodies from mother or
antibodies are injected into a patient
2. Duality of the Immune System
a) __________________________________ -the production of antibodies which
circulate as soluble protein in the blood and attack free germs
b) __________________________________- produces cells which attack infected cells
directly
C. The Humoral Immune Response
1. _______________________________ or B cells are activated by antigens directly or by
T lymphocytes
2. Activated B cell begin to produce two other types of cells
a) _____________________________ -survive for long periods of time and proliferate
rapidly when exposed to the same antigen
b) _____________________________ -begin producing as many as 2000 antibodies per
second for 4 to 5 days
c)
3. One Method of B Cell Activation
a) T independent antigen
binds to the B cell and
activates the B cell
b) Activated B cell divides
forming memory cell and
plasma cells
c) Plasma cells begin production
of antibodies
4. Antibodies constitute a group of proteins called _______________________Ig
a) Antibody Structure
•
•
•
Y shaped molecule composed of 4 polypeptide chains: 2 light (small), 2 heavy
chain (larger)
All four chains have regions that are constant and regions that are variable
The variable regions function as __________________ and are specific to
each antigen
b) Types of Immunoglobulins:
1) __________ Five Y-shaped monomers arranged in a pentameter.
Appear in initial antigen exposure and trigger agglutination.
2) __________: Y-shaped monomer. Most abundant. Readily crosses
blood vessels. Binds to antigen and activates compliment
3) __________: Dimer of 2 Y-shaped monomers. Abundant in mucus
membrane, saliva & tears
4) __________: Y-shaped monomer bound to B cells. Used as a
receptor for T independent antigens
5) __________: Y-shaped monomer on basophils and mast cells.
Antigen binding stimulates release of histamines
c) How Antibodies Work:
1) __________________________ -block viral and bacterial binding
sites
2) __________________________ -attach and immobilize germs
forming clumps which are then engulfed by macrophages
3) ____________________________________ proteins which lyse cell
membranes
5. Activation of B Cells by Macrophages
a) When a macrophage engulfs a germ, partially digest antigens are displayed on its
membrane
b) The antigens are mounted of Major ________________________________ (MHC):
a series of glycoproteins which allow the body to recognize self from non-self
c) The macrophage is now an ________________________________ or APC and it
attracts ___________________________________
d) ____________________________ bind with the APC and are activated by il-1. TH
cells then release il-2 which:
1) Causes TH cells to reproduce and stimulates Killer T cells
2) Activates B Cells
e) B cells attach to T cells and begin to make __________________________ (which
produce antibodies) and ____________________________
6. T dependent and T independent Antigens
a) ___________________________________ -only stimulate the production of
antibodies with the help of T cell
b) ___________________________________ -can bind directly with Ig D appearing on
the B cell and stimulate the B cell without T cells
C. Cell Mediated Responses
1. T cells cannot be activated by free antigens in the body fluid
2. ___________________________________________ on APCs attract T cell. T cells
bind with the complex and trigger:
a) Activation of B cells
b) The production of more Helper T cells
c) The production of _______________________________ (T killers)
3. T Helper Cells are able to stimulate other lymphocytes by sending and receiving
______________________
a) When T Helpers bind to APCs, the APC releases __________________________
b) The cause the T Helper to release _____________________________ which causes
T Helpers to divide and helps activate B Cells and Cytotoxic T cell
4. ____________________________________ (T-Killers) are cells which destroy cells with
antigens directly
a) Attach to cells with antigens
b) Release ________________________, a protein which will lyse cell membranes
c) This kills the cell the cell and prevents it from reproducing new viruses