disease and immunity Flashcards
(26 cards)
what is a pathogen
an organism or virus that causes disease
what is a transmissible disease
a disease in which the pathogen can be passed from one host to another
pathogens way be:
- fungi (athletes foot)
- bacteria (streptococcus)
- protoctists (plasmodium malaria)
- viruses (HIV)
how do pathogens get transmitted
A) through direct contact
B) indirect
who do we control the spread of bacteria
1) hygienic food preparation
2) clean water supply
3) good personal hygiene
4) proper waste disposal
5) sewage treatment
6) vaccination
how is cholera caused
by a bacterium which is transmitted in contaminated water
the bacteria releases a toxin
the toxin causes the intestine to release chloride ions in the small intestine
the water potential decreases so water enters by osmosis
what are the symptoms of cholera
diarrhoea
what is the treatment for cholera
rehydration therapy
antibiotic treatment
what are our bodies mechanical barriers
- skin
- hair in nose (filters
- eyelashes
what are our bodies chemical barriers
- mucus ->traps bacteria (produced by goblet cells in the trachea bronchi)
- hydrochloric acid in the stomach -> kills bacteria
what cells defend our body from pathogens
white blood cells:
a) phagocytes -> engulf
b) lymphocytes -> produces antibodies
how can our bodies defence be enhanced
by vaccination
why do the phagocytes have an irregular nucleus
so they can squeeze between the cell lining of the capillaries, escape and move to the site of infection
what happens after they engulf the pathogen
they digest it using enzymes
what is active immunity
defence against a pathogen by antibody production in the body
what is an antigen
molecule on the surface that triggers an immune system/ antibody production
what is an antibody
protein produced by lymphocytes in lymph notes that recognise & binds to a specific antigen and
a) directly destroys the pathogen
b) marks it for destruction by phagocytes
how do we get long term immunity
some lymphocytes remain in the lymph notes and form memory cells
what is the order of active immunity
- pathogen enters
- lymphocytes produce antibody
- antibody recognises antigen
- destroys or marks
- creation of memory cells
how do we gain active immunity
after infection
by vaccination
what is vaccination
introducing to the body a weakened pathogen or their antigen
antigen trigger and immune response, ie lymphocytes produce antibodies
memory cell are produced -> long term immunity
why is vaccination important
protects individuals receiving the vaccine and reduces the spread of the disease
what is a drug
any substance taken into the body that modifies or alters chemical reactions in the body
what are antibiotics used to treat
bacteria
