Health is a state of
physical, mental and social
well-being, which includes
the absence of disease and
infirmary.
Disease is a
condition that
impairs the normal
functioning or an
organism
A pathogen is an
organism that can
cause damage to the
organism it infects (the
host)
A parasite is an organism that
lives on or in another organism
and causes damage to that
organism
Malaria
Malaria is caused by the parasite
Plasmodium. The Female Anopheles
mosquito transmits the disease. They are
vectors, they don't cause the disease but
they spread it. The plasmodium affects
the liver and the RBC.
AIDS
It is caused by the HIV virus. Infects human white
blood cells. HIV reproduces inside cells . AIDS
is where the immune system deteriorates and
fails due to the loss of white blood cells.
TB
Caused by a bacterium. Transmitted by coughs
and sneezes. They don't show symptoms but if
weakened by another disease they will show
symptoms
Global impact
Malaria, TB and HIV are most
common in sub-Saharan Africa
and other developing countries.
Limited healthcare, education,
equipment and overcrowded.
The prevalance of them
slows down social and
economic development
because it increases death
rates and reduces
productivity.
Info can be used to find out where
people are most at risk. Predict
epidemics. Research. Allow
organisations to aid where it's most
needed
Smoking and diseases
Evidence linking smoking to disease
98% of people
with emphysema
are smokers
A smoke is 18 times
more likely to develop
lung cancer than a
non smoker
Some substances in
smoke contribute to CHD
(not fully sure)
Short and long term effects
Short term effects: tar
damages cilia and
stimulates goblets cells to
secrete more mucus
Long term effects: Smokers cough,
results in scar tissue, smooth muscle
thickens reduces lumen size, makes
the elastic fibers unable to recoil
Diseases
Emphasyma
Type of COPD. Produces
an enzyme that breaks
down elastin in the elastic
fibres. Reduces surface
area. Shortness of breath
and wheezing. Increased
breathing rate.
Chronic bronchitis
Type of COPD. Damage of the
cilia cause more mucus to be
secreted. Increases the coughing.
Microorganisms multiply in mucus
and cause infections.
Stroke
Rapid loss of brain function due
to a disruption in the blood
supply to the brain. Can be
caused by a blood clot
Lung cancer
Smoke contains lots of
carcinogenic compounds.
Benzopyrene is the most
harmful. Changes the genetic
material (mutations)
Atherosclerosis
Damage to the lining of the arteries,
WBC move into the area. Over time,
WBC, lipids and connective tissue
build up and harden to form an
atheroma. It partially blocks the artery
and restricts blood flow
CHD
When coronary arteries have lots of
atheromas in them. Reduces blood flow
to the heart and cause angina or heart
attack because of the lack of oxygen