B10 - Disease and Immunity Flashcards
pathogen definition
disease causing (micro) organism
transmissable disease definition
disease in which the pathogen can be passed from one host to another
how is a pathogen transmitted? [2]
direct contact and indirectly
examples of direct contact transmission [2]
-blood / other body fluids
-direct contact
examples of indirect transmission [5]
-contaminated surfaces
-contaminated foods
-contaminated animals
-contaminated air (airborne)
-vectors
5 body defenses against pathogens? what are these called?
FIRST LINE OF DEFENSE:
-skin
-hairs in the nose
-mucus
-stomach acid
-white blood cells
5 ways to control the spread of disease
-clean water supply
-hygienic food preparation
-good personal hygiene
-waste disposal
-sewage treatment
active immunity definition
defense against a pathogen by antibody production in the body
antibodies definition
proteins that bind to antigens
what do antibodies do to pathogens?
-direct destruction of pathogens
-marking of pathogens for destruction by phagocytes
how is active immunity gained? [2]
-after an infection by a pathogen
-vaccination
what is the process of vaccination?
1) weakened pathogens / their antigens are put into the body
2) antigens stimulate an immune response by lymphocytes which produce antibodies
3) memory cells are produced that give long term immunity
what conditions do pathogens need to reproduce? [3]
-warm environment
-food / nutrients
-moisture
disease definition
state of the body when it can’t cope with changes by the normal homeostatic methods
what are parasites?
pathogens that benefit from the host but the host is harmed
what pathogen is flu caused by?
virus
what pathogen is TB caused by?
bacteria
what pathogen is athlete’s foot caused by?
fungus
what pathogen is malaria caused by?
protoctist
3 examples of non-transmissible disease
-cancer
-colour blindness
-cystic fibrosis
what are non transmissible diseases caused by? [2]
-genetics
-diet/lifestyle
4 facts about viruses
-they are particles, not cells
-no cellular structure (just protein coat & genetic material)
-can only reproduce inside other living cells
-they are both pathogens and parasites
direct contact definition
directly from one organism to another
indirect contact definition
from one organism to another via an intermediate
how is flu transmitted?
airborne - inhaling droplets in the air containing the pathogen after someone has sneezed / coughed
how is cholera transmitted?
water - drinking contaminated water
how is food poisoning transmitted?
food - eating contaminated food
how is athlete’s foot transmitted?
direct contact - touching infected objects / people
how is malaria transmitted?
animal vectors - getting bit by an infected insect
open wounds which allow the entry of pathogens
how is chlamydia transmitted?
sex - sexual intercourse with an infected person
how does the freezer and fridge help reduce the transmission of pathogens?
fridge - slows down pathogens’ reproduction
freezer - stops pathogens’ reproduction
process of cleaning water supply
filter and add chlorine
how does clean water supply prevent transmission of disease?
kills pathogens while cleaning
process of hygienic food preparation [4]
-CLEAN cooking utensils and surfaces during food preparation
-SEPARATE cooked and uncooked foods to avoid contamination
-COOK food thoroughly and well to destroy any remaining pathogens (bacteria)
-CHILL food to slow down / stop pathogens’/bacterias’ reproduction
how does hygienic food preparation prevent transmission of disease? [3]
Reduces the spread of pathogens as during the process, pathogens are killed
process of good personal hygiene
wash hands and body
how does good personal hygiene prevent transmission of disease?
prevents the spread of disease:
-we are less likely to become ill, which means less likely to pass on harmful microorganisms
-during the process, pathogens are killed
process of effective waste disposal
-not letting rubbish build up
-separating infected things such as used bandages and needles
how does effective waste disposal prevent transmission of disease?
prevents the spread of disease
-food waste may have harmful microorganisms
–> these may be spread by animals (rats & birds) or humans
process of sewage treatment
good system for treatment of sewage
-treated water
-faeces (may contain pathogens) are removed from waste water
how does sewage treatment prevent transmission of disease?
-removes harmful bacteria & dangerous chemicals
-prevents contaminating house water or rivers (may effect the ecosystem)
2 mechanical barriers to stop pathogens from getting in to our bodies
-skin
-hairs in nose
2 chemical barriers to stop pathogens from getting in to our bodies
-stomach acid
-mucus (ciliated cells)
how does the skin stop pathogens from getting in to our bodies? [2]
-when skin is broken (cut), scab forms quickly as temporary barrier to stop entry of pathogens
-acts as a physical barrier
how do hairs in the nose stop pathogens from getting in to our bodies? [2]
-stops air pathogens from going in to the lungs (which could cause infections)
-traps particles from the air that could contain pathogens
how does stomach acid stop pathogens from getting in to our bodies? [2]
-stomach acid kills pathogens that enter
-stomach acid kills the mucus that we swallow
how does mucus stop pathogens from getting in to our bodies? [3]
-mucus traps air particles & pathogens in the air
-cells lining trachea secrete mucus
-mucus is drafted back up to the throat (via cilia cells) to be swallowed to the stomach
what happens if microorganisms enter our blood stream? [2]
immune system prevents the microorganisms using white blood cells (phagocytes & lymphocytes)
what do phagocytes do?
destroy pathogens by phagocytosis
what do lymphocytes do?
make antibodies
antigen + antibody facts [2]
-antibody and antigen are complementary in shape
-every type of micro organism has a different antigen so a different antibody is needed to match them
function of phagocytes? [2]
-engulf and digest pathogens
-kill pathogens by phagocytosis
function of lymphocytes? [2]
make antibodies to destroy pathogens / mark them for the phagocytes
3 adaptations of phagocytes
-contain digestive enzymes in the cytoplasm
-irregular shape to squeeze through gaps in capillary walls
-sensitive cell membrane to detect micro organisms
2 adaptations of lymphocytes
-pathogens have special protein markers
-large nucleus that contains many copies of genes for antibody production
what does it mean to be immune to a disease?
your body has antibodies in your blood so you can’t catch the disease
how does vaccination work? [2]
-causes lymphocytes to produce antibodies to that pathogen (stimulating an immune response)
what 2 things does vaccination cause your body to produce?
-antibodies
-memory cells (long lasting immunity)
what do memory cells do?
keep instructions for making a type of antibody for when the real pathogen enters the body
why are memory cells important? [3]
next time the pathogen enters, antibodies can be made very quickly and in large quantities
–> pathogen is destroyed before it can reproduce to cause illness
2 ways vaccination can control the spread of disease [4]
-individuals who are vaccinated are immune
–> they won’t develop the infection and pass it on to someone else
herd immunity:
-when a large enough percentage of a population has been vaccinated, it helps protect individuals that haven’t been vaccinated
–> less likely to catch disease because there are fewer people to catch it from (fewer places for the pathogen to reproduce)
