immune system Flashcards
what is phagocytosis
cell eats foreign matter
what is a pathogen
anything that can cause a disease = germ
what are the types of pathogens
bacteria
viruses
fungi
worms
parasites
why do we need good bacteria
te keep away bad bacteria
what are our barriers against bacteria
skin, blood, mucous membranes
(digestive & respiratory tract)
what are responses to pathogens
phagocytes
inflammatory response
fever
how do phagocytes know what to eat
foreign celss are labelled by molecular tags
what is the function of the immune system
protect against infections
repair wounds
defend against cancers
how can infections enter the body
skin/mouth/ears/nose/throat/lungs/intestinal tract/openings of urinary + genital organs
what are the two basic defenders of the body
cells: phagocytes
chemicals: antibodies
what are antibodies
Y-shaped protein
each responds to a specific antigen
what is the purpose of the special section of an antibody
sensitive to a specific antigen+ binds to it in some way
where is the immune system located
mostly in the lymph glands (linked by lymph vessels),tonsils, spleen, thymus…
when do the germs win
large invasion force
weak immune system
what can weaken the immune system
old age, drugs and diseases
what is an auto-immune disorder
when the body’s immune system attacks (part of) itself
how do you get an auto-immune disorder
Runs in families, but environmental trigger is also required
what are the two groups of auto-immune disorders
- affecting a single organ
- affecting cells or tissues that are present in more than one organ
what are some auto-immune disorders
systemic lupus erythematosus
rheumatoid arthritis
primary biliary cirrhosis
what does SLE stand for
systemic lupus erythematosus
what are symptoms of systemic lupus erythematosus
rash across the cheeks, painful joints,may also affect kidneys/heart/brain
what does rheumatoid arthritis do
destroys the lining of joints & tendons
-> they become chronically inflamed, painful and deformed
what does primary biliary cirrhosis do
destroys the bile ducts in the liver➔
disruption of the flow of bile /
-> jaundice
what is immunodeficiency
immune system is under active
fails to deal with invaders
-> infection prone
what are causes of immunodeficiency
genetical lack of lymphocytes or antibody,malnutrition, infections (e.g. aids, glandular fever, …)
how do you get a viral infection
inhale a few virus particles:
into mucus via cilia to stomach
normal: virus killed
occasionally: virus attacks
what do the lymphocytes in case of attack
interferon
killer lymphocytes destroy the infected cells
what does interferon do
shuts down protein synthesis in cells close to the site of infection
-> virus needs these to spread
Why don’t B-memory cells prevent us from getting influenza twice
Viruses are able to change their outer coat of protein:
→ in this way they avoid being recognized!
how do we fight a bacterial infection
chemical reactions by complement proteins:e.g. stick to microbes (‘label’) or attract phagocytic cells
+ dilating effect on blood vessels= makes the wound hot, swollen + painful
are we clean
no we carry a plethora of different germs, these are either good or harmless to our health. Problems occur when we get sick/older/injured
Is it safe for a dog to lick a baby
depends, it’s hard to contract diseases from a dog because it’s a different breed. However dogs also lick their private parts and eat fecal matter so it’s not really hygiënic
+ babies make eye contact which a dog can see as a challenge in dominance
