Describe: Defence Mechanisms - Humans

b.stev

PRIMARY IMMUNE RESPONSE

lag (wait) period of 10 days – 4 weeks

at first no antibodies are produced

EFFECTED: sneeze/ illness/ fever/ cough

antibodies made by B cells > prepare to divide and then replicate to multiply

pathogenpathogen specific antibodies appear & out compete infection, then subside

quality of the made antibody improves

SECONDARY immune response previous interaction with pathogen gives quick action to compete with the pre-made antibody

NO lag (wait) period - specific quality to strain has been reached

recovery to infections is more rapid due to this memory response

IMMUNOGLOBULINS (antibody)

IN: blood and body fluidsUSED: identity to neutralise foreign bodiesPRODUCED: B lymphocytes (B cells)

CIRCULATES in the blood- binds to pathogen before entering the cell- stimulates it’s removal, coats the pathogen for identity by phagocyte: (a digester)- can stimulate direct response of complement pathway

IT IS THE,“TIP,” that differs to allow millions of varieties: - gives specific response to particular foreign body- attaches to commence immune response- TIP binds: identity of pathogen: called the “EPITOPE”

ANTIBODY :produces attachment of a TAG to the pathogen: that shows expression for the next phaseidentity to it’s MATCH of the B cell & then T cell

(Wikipedia, 2008)

ANTIBODY IgD IgE IgG

binding site

pathogen5 DIFFERENT

isotopesknown as:

IgA

IgM

IgA: mucosal areas (saliva/ tears/ breast milk) urogenital/ gut/ respiratory

IgD: less defined: use on unknown pathogens

IgE: allergens – triggers histamine release protects against - parasitic worms

IgG: crosses the placenta for immunity to fetus provides most antibody based immunity

IgM: expressed on B cells & secreted rapidly addresses early stages of response before specified responses produced

spread through body lymph nodes/ spleen/ liver/ blood

released at several thousand per second

eliminates/ prevents pathogenic challenge

surveillance for pathogens

works as the - antigen presenting cell

THIS eventuates to creation of : memory B cell

EACH - specific receptor, binds to certain pathogen(s)

PRODUCES antibodies

B LYMPHOCYTES (B cell)

divide in bone marrow to form CLONES

(Wikipedia, 2008)

originates in the bone marrow

FUNCTION:

o pathogen is absorbed & fragmented

o a complex on it’s surface is made to display this, made of : genomic region – known as, MHC & pathogen fragments

o THIS FACILITATES RESPONSE – presentation attracts

o lymphocytes (T cell) via their receptor cell

ANTIGEN PRESENTING CELLS (accessory cell)

(HON Foundation, 2002)

T cell activates when it encounters a B cell that displays it’s specific MHC & fragmented pathogen complex

T LYMPHOCYTES (T cell)

originates in bone marrow THYMUS produces a precursor cellsome TYPES:

HELPER : activation, rapid dividing & secretion (cytokines) – regulate/ help immune response

CYTOTOXIC : destroy virus infected/ tumour cells - cause of transplant rejection

MEMORY : persists after infection has subsided - quick action if activated by their MHC coagent

REGULATORY : closes response of subsided infection NATURAL KILLER : destroys virus infected/ tumour cells

immune COMMUNICATIONCOMMUNICATION is AIDED VIA:

- MHC (major histological complex)

- cytokines: interleukins

CELL SURFACE RECEPTORS: MHC PROTEINS

MHC: called the > major histological complex

FUNCTION:attracts specific cells

consists of genomic material- proteins are coded with this & expressed on cell’s outer surface

after B cell has fragmented the PATHOGEN …

B cell then “expresses” these fragments in a complex

: to attract the T-cell via the use of the MHC complex

(Wikipedia, 2008)

FUNCTION:

the glycoprotein acts as a signal in a variety of processes example: interleukin(s)

BINDS: specific cell receptor – changes it’s function

INCREASE OR decrease: action of cells and production

CYTOKINESPRODUCED: blood cells (haematopoietic) & other cells - classed: glycoprotein

acts as a signal to activate next response - complexity of white blood cell processes - stimulate/ suppress: immune response

utilised in: many of the immune processes - cytokine molecule – (glycoprotein)

mediates white blood cell communication

INTERLEUKINS

PRODUCED: variety of cells

ADMINISTERED mostly:hypodermic needleorally

VACCINATION

TYPES:

live - weakened forms of the pathogen

killed/ inactivated forms: pathogen

specific proteins: act on the pathogen

administered PATHOGENIC material that ... produces immunity to disease ... response creates memory cells

examples: smallpox/ rubella/ tetnaus/ hepatitis

(Wikipedia, 2008)

Bibliography

HON Foundation. (2002). HON allergy glossary antigen - presenting cell (APC). Retrieved October 21, 2008, from https://www.hon.ch/Library/ Theme/Allergy/Glossary/apc.html - 11k -

Wikipedia. (2008). B cell – wikipedia, the free encyclopedia. Retrieved October 21, 2008, from http//:en.wikipedia.www. org/wiki/ B_cell - 75k -

Wikipedia. (2008). T cell – wikipedia, the free encyclopedia. Retrieved October 21, 2008, from http//:en.wikipedia.www. org/wiki/ T_cell - 59k -

Wikipedia. (2008). Cytokine – wikipedia, the free encyclopedia. Retrieved October 21, 2008, from http//:en.wikipedia.www. org/wiki/ Cytokine- 118k -

Wikipedia. (2008). Interleukin – wikipedia, the free encyclopedia. Retrieved October 21, 2008, from http//:en.wikipedia.www. org/wiki/ Interleukin- 89k -

Wikipedia. (2008). Major histocompatibility complex – wikipedia, the free encyclopedia. Retrieved October 21, 2008, from http//:en. wikipedia.www. org/wiki/Major_histocompatibility _ complex - 69k -

Wikipedia. (2008). Antibody – wikipedia, the free encyclopedia. Retrieved October 21, 2008, from http//:en.wikipedia.www. org/wiki/ Antibody- 192k -

Crudup A. B. (n.d). Primary and secondary immune responses. Retrieved October 21, 2008, from http//: www.meredith.edu/kenya/prim_ secon_immune_responses.pdf -