specific immune response Flashcards
phagacyte
all types of white blood cell that is involved in phagacytosis
5 types of red blood cells
Never. Neutrophil
Let. Lymphocyte
Monkeys Monocyte
Eat. Eosinophil
Bananas. Basophil
two examples of phagacytes
neutrophils and macrophages
2 types of lymphocytes
- B lymphocytes
- T lymphocytes
T - lymphocytes
made in bone marrow
matured in thymus gland
cell-mediated immunity
T lymphocyte cells respond to cells that have been changed in some way.
what do cells need to be to invoke a response?
Changed…
by viral infection,
antigen processing,
mutation,
or to cells from transplanted tissue.
First step in cell mediated response
- After phagacytosis, macrophages process antigens from the surface of the pathogens to become antigen presenting cell
- the receptors of some t- helper cells fit with the specific antigen of the antigen presenting cell.
Fun fact about t- lymphocytes
There are about 10 mill different types of t- cells, each type with a different surface receptor
second step in cell mediated response
T helper cell activated and produces interlukins.
Stimulates more t - cells to divide more rapidly by mitosis.
what happens to activated t- helper cells
they are cloned
cloned t- cells, may develop onto or produce…
- develop into t- memory cells
- produce interlukins to stimulate phagacytosis
- produce interlukins to stimulate B cells to divide.
- develop into T killer cells.
What do all differentiated t cells have?
the same surface receptors as eachother.
T helper cells
- release interlukins
- interlukins stimulate other t- cells to differentiate
- interlukins stimulate B cells to develop and mature
- interlukins stimulate B cells to divide.
- interlukins stimulate and attract macrophages to ingest the antigen antibody complexes.
T-killer cells…
- a cytotoxic cell
- have receptors that are complementary to antigens of the infected cell.
- binds to infected cells and releases perforins, which make the membrane freely permeable, killing the cell
What are cytotoxic cells?
A type of immune cell that can kill certain cells, including foreign cells, cancer cells, and cells infected with a virus.
T- memory cells..
- stay in your body a long time after infection
- called immunological memory
- if they encounter the same pathogen again, they divide rapidly to form a huge colony of t-killer cells.
T memory cells are part of
immunological memory
T regulator cells
- suppress the immune system, acting to control and regulate it.
- stop immune response once a pathogen has been eliminated.
- makes sure the body recognises self antigens and does not begin an autoimmune response.
- interlukins are an important part of this.
Cytokines
cell signalling molecules that attract white blood cells to the site of damage.
released in inflammatory response as well.
opsonins
molecules that coat the pathogen so phagacytes can easily bind to it.
opsonins include…
- antibodies
- complement proteins
- other small circulating proteins
Interferons
a chemical (cytokine) released by virus infected cells that alerts neighbouring cells and stimulates them to heighten their antiviral defence
which cells are involved in the Humoral response
- b lymphocytes
- plasma cells
- memory cells
Where do B lymphacytes mature
in the bone marrow
what is the humoral response?
when the body responds to antigens outside of cells. Like APCs, bacteria and fungi.
give two properties of antibodies…
- soluble in blood and plasma
- when they are formed, they are not attached to cells.
give two properties of antibodies produces by the humeral response…
- soluble in blood and plasma
- when they are formed, they are not attached to cells.
another word for antibody
immunoglobulin
state what happens in the stage just before clonal selection… humoral response
- b lymphocytes have specific antibodies attached to their cell surface membrane.
- a specific b cell’s complementary antibodies will attach to the antigens or toxins produced by a pathogen.
- b cells engulfs and processes antigens and becomes an APC
what do toxins act as in the humeral response
as antigens
explain what happens in colonal expansion
- b cell that has become an APC activated T helper cells bind to it.
explain what happens after colonal expansion
interlukins from activated t helper cells activate B cells
Explain colonal expansion
activated b cells divide into clones of plasma cells and memory cells.
clonal expansion ….
increases number of activated B- cells.
Humoral response b memory cells
- if the body is infected by same pathogen, memory cells will differenciate into plasma clones.
humoral response- plasma cells
- produce antibodies complementary to antigens of pathogen.
- act as opsonins and agglutinins
difference between primary and secondary response
primary response-to a newly encountered antigen
Secondary response- to a previously encountered antigen
how antibodies defend the body
- pathogens can no longer invade a host cell once an antigen/antibody complex is formed.
- antibody antigen complex acts as opsonin, so the complex is easily engulfed and digested by phahocytes.
- antibodies can act as agglutinins. antigen antibodies complex pathogens clump together, making them easily detected and engulfed in larger numbers by pathogens.
agglutinins
chemixals that cause oathogens to aggrivate together, aiding phagacytosis.
antibodies structure explained (3)
- two identical long polypeptide chains = long chains
- two shorter polypeptide chains = short chains
- disulfide bridges hold together polypeptides and also hold the chains together.
antibody regions explained
- the bottom of the antibody (stem of the y) is the constant region.
- the tips of the antibody is the variable region.
- hinge region st the crux of the Y before the strands branch out
draw a picture of an antibody. label its features
https://www.savemyexams.com/a-level/biology/aqa/17/revision-notes/2-cell-structure/2-5-cell-recognition–the-immune-system/2-5-9-antigen-antibody-complex/
Function of hinge region
makes the antibody flexible so it can bind to two separate antigens, one in each variable region.
neutralisation- antibodies
antibodies bind to pathogen and prevent them from invading a cell
What are macrophages
monocytes that leave the bloodstream and enter tissue.
