Human defence Flashcards
pathogen
disease causing microorganism
immunity
ability to resist infection
name 2 organs in the human body which are specific to the immune system
lymph nodes
spleen
give 2 reasons why blood clotting is so important
prevents pathogens from entering the blood
prevents excess blood loss
what are lysosomes
enzymes that break down the bacterial cell wall
general defence system
the non specific methods used to prevent the entrance of pathogens into the body and killing of those who do
specific defence system
the immune response, defends the body against specific pathogens that have gained entry to the body
what are the first lines of defence
barriers to entry of pathogens
name the barriers of entry of pathogens
the skin- physical barrier
oil sebaceous glands- prevent lodging of pathogens
mucus producing cells and cilia protect respiratory tract
lysosome
blood clots
symbiotic bacteria in the vagina form lactic acid which inhibits growth of pathogens
where are lysosomes produced
sweat tears and saliva
second lines of defence
inflammatory reaction
phagocytic white blood cells
defence proteins
inflammatory reaction
increased temperature, lots of white blood cells rush to area of infection
function of phagocytic white blood cells
scavenge around the blood and engulf any pathogens
what are the 2 types of defence proteins
complement
interferon
function of complement proteins
make a hole in bacteria fill with fluid and burst
function of interferon proteins
make surrounding cells resistant to a virus
name 2 places in the body where mucus membrane linings are found
trachea
nose
name 2 places in the body where acid is found
vagina
stomach
function of lymphocytes
to produce antibodies
antibodies
proteins produced by the body in response to an antigen
antigen
substance on the surface of a bacteria/ virus that causes antibody production
describe the antibody antigen response
every antigen causes a specific antibody to be produced
the specific antibody attaches to the antigen on the invader resulting in the destruction of the pathogen in 1 of 2 ways:
1. the cell wall becomes permeable and bursts and dies
2. a phagocyte recognises the antibody-coated pathogen and engulfs it
induced immunity
the ability to resist disease caused by specific pathogens by the production of antibodies
active immunity
when a person makes its own antibodies in response to foreign pathogens
what is induced active immunity
when the body has learned to produce the correct antibody and the body remembers it
how is induced active immunity made artificialy
vaccination
vaccine
a non disease causing dose of a pathogen introduced into a person to induce an antibody response, leading to immunity to that disease
passive immunity
when a person is given the antibodies that were formed by another individual
is passive immunity long term or short term
short term- lasts until the antibodies are broken down in the recipients body
examples of passive immunity
breastfeeding
tetanus shot
immunisation
occurs when we produce or are injected with antibodies against a pathogen
give the precise location in the body where lymphocytes are produced
bone marrow/ thymus
identify the type of lymphocyte that produces antibodies
plasma B
identify the part of a virus that recognised by antibodies
antigen
explain why antibiotics are not prescribed to cure COVID-19
it is a viral infection, antibiotics only treat bacterial infections
name the 2 types of induced immunity
passive
actice
give one difference between active and passive immunity
active- long lasting
passive- short term
write a note on vaccination
vaccine= non disease causing dose of a pathogen
introduces the antigen
activates memory B + T cells
stimulates antibody production by lymphocytes
explain why active immunity results in long lasting immunity
a person can produce their own antibodies and memory T remembers the antigen
what are the 2 types of lymphocytes that are produced by the body
B + T lymphocytes
B lymphocytes
recognise one specific antigen and produce antibodies in response to that antigen
which B lymphocyte specifically produces antibodies
plasma B
what do memory B cells do
remember the antigen and can make the same specific antibody
where do T lymphocytes mature
thymus gland
function of T lymphocytes
they allow for a quicker more intense production of antibodies (THEY DO NOT PRODUCE ANTIBODIES)
what are the 4 types of T lymphocytes
killer T
helper T
suppressor T
memory T
function of helper T
recognise antigen, stimulate B cells to produce antibodies and activates killer T
function of Killer T
stimulated by helper T
attack and destroy infected cells
how do killer T kill infected cells
produce perforin which forms pores in the infected cell
function of suppressor T
stop the immune response
function of memory T cells
remember the antigen and allow for long term immunity
stimulates memory B cells
outline how any 1 feature of the human general defence system works
skin is a physical barrier that secretes oil
mucus in nose and trachea traps dirt and dust
why is a person more likely to pick up an infection in hospital
they are already sick
immune system is weaker
antibiotic resistance
name a group of white blood cells other than lymphocytes
monocytes
under what circumstance might an antibody rather than a vaccination be given
if the infection has already occurred or no vaccine is available
vaccine
non disease causing dose of a pathogen introduced to induce an antibody response leading to immunity to that disease
what are the 2 types of lymphocyte produced by the body
B and T
where are B lymphocytes matured
bone marrow, spleen, tonsils and other lymph nodes
