Health and Disease Mind Map Unit 2 Section 5 Biology AS Level OCR
Including: infectious disease, the immune system, immunity & vaccinations, smoking & disease
Health = a state of physical,
mental and social well-being,
including the absence of
disease and infirmity.
A pathogen = an organism
that can cause disease e.g.
bacteria, fungi and viruses.
Parasite = an organism that lives in
or on another organism and causes
damage to the organism e.g.
tapeworms, roundworms and fleas.
Diseases can also be caused by
genetic defects, nutritional deficiencies
and environmental factors e.g. toxicity.
Infectious disease = diseases that
are passed between individuals
e.g. malaria, HIV and TB.
Malaria
Caused by the
parasite Plasmodium
Plasmodium is a eukaryotic,
single-celled parasite.
It is transported by mosquitoes, which
are vectors (they don't cause the
disease but spread the infection by
transferring it from one host to another.
Mosquitoes transfer the
Plasmodium parasite into an
animal's blood when they feed
on them.
Plasmodium infects the
liver and RBCs and
disrupts the blood supply
to the vital organs.
AIDS
Caused by HIV
HIV infects human white blood cells as it can
only reproduce inside the cells of the organism
it has infected because it cannot reproduce on
its own.
After the virus has reproduced, it kills
the WBC at it leaves.
HIV is spread by unprotected sex,
infected bodily fluids e.g. blood by
sharing needles, and from mother
to foetus (through placenta/breast
milk/during childbirth)
AIDS is a condition where
the immune system
deteriorates and
eventually fails due to the
loss of WBCs. The
sufferer is more
vulnerable to other
infections e.g. pneumonia.
TB
Tuberculosis is a
lung disease
caused by the
bacterium
Mycobacterium
tuberculosis.
It is spread through droplets
in the air e.g. when a person
sneezes and someone else
breathes it in.
Many people with TB don't show symptoms but
if they become weakened e.g. by malnutrition,
then the infection can become active. Then they
will show symptoms and pass it on.
Global Impact
Developing Countries
Limited access to good
healthcare so people are less
likely to be diagnosed and treated.
Limited health education so
people do not learn about
the transmission of diseases.
Limited equipment to
reduce spread of
infections.
Overcrowded
conditions
increases risk of
droplet
transmission.