describe - defence mechanisms in humans
DESCRIPTION
primary,secondary immune response, immunoglobulins, antibodies, B cells, T cells, B lymphocytes, T lymphocytes,Interleukins, cytokines, MHC complex, cell surface receptors, VaccinationTRANSCRIPT
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 -