Immunity + Vaccinations Flashcards
define microbes
organisms that are microscopic
Fungi: how big are they? can they be seen under a lit microscope? how many cells are they made of? do they have a nucleus? do they have a cell wall? how do they reproduce? what examples are there? what diseases do they cause?
very large or 5-10 um (biggest out of microbes) yes 1 or many yes yes (chitin) spores or cell division yeast, Mucor, Penicillium athletes foot, thrush
Protoctista: how big are they? can they be seen under a lit microscope? how many cells are they made of? do they have a nucleus? do they have a cell wall? how do they reproduce? what examples are there? what diseases do they cause?
chlorella 5-10 um/ amoeba 20-200 um yes unicellular yes most do not cell division amoeba, plasmodium, chlorella malaria, sleeping sickness
Bacteria: how big are they? can they be seen under a lit microscope? how many cells are they made of? do they have a nucleus? do they have a cell wall? how do they reproduce? what examples are there? what diseases do they cause?
1-5 um yes although they are so small unicellular no yes cell division E.coli, lactobacillus pneumonia, TB
Virus: how big are they? can they be seen under a lit microscope? how many cells are they made of? do they have a nucleus? do they have a cell wall? how do they reproduce? what examples are there? what diseases do they cause?
0.01-0.2 um (smallest out of microbes) no --> only under electron microscope no no no in a host cell flu virus, HIV cold, influenza, AIDS
how does nose and mouth act as a defence for us
coughing/sneezing/nasal hair
physical barrier
how do the eyes act as a defence for us
tears contain the enzyme lysozyme which kills bacteria
chemical barrier
how does the stomach act as a defence for us
strong hydrochloric acid here kills most bacteria present in food
chemical barrier
how do our longs act as a defence for us
lined with ciliated cells and muscles to trap and sweep away microbes
physical barrier
how do females vaginas act as a defence for them
acid conditions here will destroy some bacteria
chemical barrier
how does skin act as a defence for us
barrier to infection and repairs itself quickly when broken
physical barrier
how does blood act as a defence for us
platelet cells in blood will form a blood clot to stop entry of microbes at cuts
immune system
how do lymphocytes (+++) act as a defence for us
these cells produce antibodies to destroy the poison of microbes
immune system
how do lymphocytes (YY) act as a defence for us
these cells produce antibodies which bind to the microbes
immune system
how do phagocytes act as a defence for us
these cells in the blood engulf invading bacteria and digest them using enzymes
when skin is injured, the most important thing is to … the wound quickly, so that … cannot enter and blood … is limited.
… are tiny cells in the blood which help close a wound. when a blood vessel is cut or broken, platelets stick together and activate the formation of a mesh made of a protein called … more platelets and also … cells are trapped in this mesh. this leads to the formation of a … which seals the cut
close microbes platelets fibrin red blood scab
explain the process of engulfment from the phagocyte
phagocytes detect the bacteria and are attracted to them. the phagocyte forms pseudopodia which surrounds the bacteria and leads to its engulfment. the bacteria inside the phagosome fuses with lysosomes and is digested.
define an antibody
a protein which can bind to an antigen on a microbe and trigger its destruction
define a lymphocyte
any substance that can stimulate the production of antibodies
explain how antibodies are produced
when infected, lymphocytes will produce antibodies to defend the body. The antibodies bind to antigens on the bacteria to trigger engulfment by phagocytes.
how are antibodies specific
different lymphocytes produce different antibodies which recognise different antigens
explain why antitoxins are produced
antitoxins are produced by lymphocytes to neutralise toxins
define a toxin
a substance produced by bacteria which can harm cellular function
1st infection results and process
- pathogen causes disease
- lymphocyte activated
- antibodies are produced
- antibodies bind to virus which gets destroyed
- memory cells are made
2nd infection results and process
- memory cells are activated and rapidly reproduce
- lots of antibodies are produced rapidly
- antibodies bind to pathogen which gets destroyed quickly without causing disease
- don’t get symptoms of disease
immunity following vaccination
- vaccine
- lymphocytes activated
- antibody production
- feeling a bit ill
- memory cells made
- catch real infection
- no illness
- memory cells quickly reproduce
- lots of antibodies produced rapidly
what are the types of vaccine
- live, but less infectious organism
- dead organism or parts of it
- modified toxins of the pathogen
- all contain antigens that trigger immune response however
natural immunity explain
active:
exposure to antigen, antibodies and memory cells made
passive:
antibodies received from mum in milk, no memory cells made
acquired immunity explain
active:
antigen injected, antibodies and memory cells made
passive:
antibodies received in injection, no memory cells made
2 reasons why we need booster injection
- vaccine does not reproduce, so dose is lower than antigen, fewer memory cells made, immune response needs to be stimulated again via booster injections
- if first injection is a dead organism, the booster injection stimulates the immune system if not exposed to the infection often so more memory cells are made this way
