Define innate immunity
pre-programmed defense responses
List the barrier defenses
- Skin and mucus
- Oil, sweat (low skin pH)
List the types of internal Defense
macrophages, interferons, inflammatory response, mast cells, natural killer cells
What do macrophages do?
engulf pathogens
What are interferons?
proteins secreted by infected cells that signal neighboring cells to defend themselves.
Describe inflammatory response
pain and swelling that occur upon injury or infection
Mast cells hold ________.
histamines
What do histamines do?
cause blood vessels to dilate, bringing extra blood which causes swelling in the tissues
Swelling in the tissues attracts what to do what?
phagocytes to come and help deal with the infection
What do natural killer cells do?
destroy infected or cancerous cells
Define acquired immunity
a defense response that is enhanced by previous exposure to the pathogen
White blood cells are also called what?
Lymphocytes
B – cells mature where?
bone marrow
T- cells mature where?
thymus
White blood cells fight _______, but each has a specific ___.
infection; job
List the factors of recognition
antigen, antigen receptors, antibody / immunoglobulin, Major histocompatibility complex (MHC)
Describe antigen
a foreign molecule that is recognized and gets a response from lymphocytes
Antigen receptors are found on _________.
lymphocytes
Antigen receptors recognize the __________ of antigens.
epitopes
What is antibody / immunoglobulin (Ig)?
a soluble form of the antigen receptor that can be secreted by the B-cell
What is major histocompatibility complex (MHC)
an infected cell protein that displays a fragment of the antigen for white blood cells to recognize.
Describe MHC Class 1
found in most cells, and calls cytotoxic T-cells that use toxins to kill the infected cell
Describe MHC Class 2
found in dendritic cells and macrophages, which are called antigen presenting cells. They use Class II MHC’s to call helper T- cells that assist other lymphocytes.
Describe clonal section
cloning of lymphocytes in response to a binding an antigen
When exposed to an antigen a B or T cell will divide rapidly making _______ cells to attack and _______ ____to store incase of future invasion.
effector; memory cells
The clonal selection is the _________ _______ ___________.
primary immune response
The Primary Immune Response peaks when?
about 10 to 17 days after infection
Describe Secondary Immunne Response
upon another exposure to the same antigen, the reserved memory cells are called upon in greater numbers
Secondary Immune Response peaks when?
response peaks 2-7 days after exposure and last longer
What do B cells do?
secrete antibodies to bind to antigens in the blood or lymph
What do Cytotoxic T-cells do?
secrete proteins that kill infected cells
Cytotoxic T-cells must be signaled by helper ______ and/ or ___ _______.
T- cells; MHC molecules
What are Helper T cells activated by?
antigen presenting cells (class II MHC)
What do Helper T cells do?
release cytokines
What do cytokines do?
call upon B and T cells to act
Describe humoral response
clonal selection of B cells. Usually fights pathogens not in cells yet
What is the main purpose of humoral response?
the antibodies secreted can neutralize pathogens or make them targets for phagocytes
Describe cell mediated response
cytotoxic T-cells destroy infected cells
Helper T-Cells can call for what cells to act?
B-Cell and T-Cell
Active immunity is _________ response.
secondary
Describe passive immunity
antibodies passive from mother to fetus can cause a secondary like response the first time a fetus is exposed to infection
What passes down passive immunity?
Passed across the placenta(IgG) and breast milk (igA)
Describe vaccination
introducing an antigen into the body to elicit clonal selection
Describe allergies
exaggerated responses to antigens. Can trigger mast cell to elicit a an inflammatory response
Sometimes the immune system turns against certain molecules naturally in the body. This is known as what?
Autoimmune disease
Lupus is against what?
DNA histones in breaking down cells
Rheumatoid Arthritis is against what?
cartilage
