communicable diseases

Created by

Martha Nutt

Cards (49)

define antigens
surface proteins on pathogens that trigger the immune response
how do vaccines work?
introduce small quantities of dead or weakened pathogens
stimulate white blood cells, which produce antibodies
then, if the same pathogen reenters the body, antibodies can be produced rapidly
define antibody
recognises and binds to specific antigens
made by white blood cells (lymphocytes)
define phagocyte
engulfs non specific pathogens
define t cells
type of lymphocyte that produces antitoxins
define b cells
types of lymphocyte that produces antibodies
define phagocytosis
when pathogen is engulfed then destroyed by a phagocyte
define antitoxin
protein produced by lymphocytes, which binds to and counteracts toxins released by pathogens
define immune system
body system which recognises and destroys foreign cells / proteins
define herd immunity
The protection given to a population against an outbreak of a specific disease when a very high percentage of the population have been vaccinated against it.
4 types of pathogens used for vaccines?
mono-clonal antibodies
similar but less harmful pathogen
weakened pathogen
dead pathogen
why did cowpox virus give immunity to small pox?
as they have similarly shaped antigens
where are antibiotics naturally produced?
by fungi
to reduce competition from bacteria when there is a shortage of food
how do antibiotics work?
by preventing the bacteria's cell wall from forming correctly
so the cells explode if they absorb water
what is the issue with antibiotics?
some bacteria develop resistance to antibiotics by mutating
what is the MMR vaccination?
against measles, mumps, and rubella
why is it difficult to develop drugs against viruses?
as viruses reproduce inside your cells
define antiviral drug
drug that kills viruses
how do new antiviral drugs work?
stops the virus enzymes from working
these are not needed by humans cells
so drugs don't cause harm to the human cells
define carcinogen
increases the risk of developing cancer
what types of microorganisms can be pathogens?
bacteria, viruses, fungi, protists
how to viruses reproduce?
by inserting genes into cells which causes them to produce more copies
how does bacteria damage cells?
releases toxins
examples of viruses?
HIV - a STI that causes aids and compromises the immune system
measles - rash, spread by droplets
tobacco mosaic virus (TMV)
examples of diseases caused by bacteria?
salmonella
gonorrhea
example of a vector?
mosquito
what are protists?
single - celled organisms
example of a disease caused by a protist?
malaria - caused by a protist which infects red blood cells. mosquitoes are the vector
example of plant disease caused by fungus?
rose black spot
example of a plant disease caused by a virus?
tobacco mosaic virus - discoloured leaves - less chlorophyll - stunted growth
where do T cells store the correct antibody?
in lymph nodes
what type of disease of cancer?
autoimmune disease
how to resistant strains of bacteria spread to other individuals?
through direct contact, contaminated surfaces or transfer between humans and animals
how can people with hiv live normal life?
antiretroval drugs, which prevent virus form replicating
if access to drugs early on in disease, can live normal life
how does tobacco mosaic virus damage plants?
mosaic, discoloured pattern on leaves
so can't photosynthesise optimally, as less chlorophyll
so not enough glucose is released for cell growth
how many ties smaller are viruses than animal/plant cells?
10,000 times smaller
how many times smaller are bacteria cells than animal cells?
100x smaller
what organ does salmonella affect?
intestines
Suggest how HPV causes cervical cancer
HPV is spread through sexual contact
virus infects cells in the cervix
virus causes mutations in the cell's DNA
mutations lead to uncontrolled cell division, which lead to cancer
State why Chlamydia can be described as a communicable disease.
transferred from person to person
caused by bacteria