When damage occurs to the lining of an
artery, white blood cells move into the area.
Over time, WBCs, lipids and connective
tissue build up and harden to form a hard
plaque - an atheroma.
The atheroma partially blocks
the lumen of the artery and
restricts blood flow.
Atherosclerosis is the
hardening of arteries due to
the formation of atheromas.
Cigarette smoke contains nicotine which causes
an increase in blood pressure and therefore
causes increased damage to the arteries.
Coronary Heart Disease (CHD)
This is when the coronary arteries have lots of atheromas in
them, restricting blood flow to the heart.
A reduction in blood flow reduces the
amount of oxygen an area of the heart
gets. This causes chest pain (angina).
Smoking increases this risk because the CO
irreversibly combines with the haemoglobin, reducing
the amount of oxygen transported in the blood, and
therefore reducing the amount of oxygen available to the
tissues and the heart muscle cells.
Nicotine in cigarette smoke makes platelets
sticky so they increase the chance of clots
forming. If this happens in the coronary arteries,
it can cause a heart attack.
The presence of atheromas also
increases the risk of clots forming.
A stroke is a rapid loss of brain function due
to disruption in the blood supply to the brain.
This can be caused by a blood clot in an artery
leading to the brain which reduces the blood supply
and therefore oxygen that can reach the brain.
Nicotine increases the risk
because it increases the
chance of blood clots.
CO increases the risk because it reduces
the amount of oxygen that can get to the
brain by combining with haemoglobin.
Gas Exchange System
Carcinogens in cigarette smoke can
cause mutations in the DNA of lung
cells which could lead to uncontrolled
cell growth and the form of a malignant
These tumours grow uncontrollably,
blocking air flow to areas of the lung.
This decreases gas exchange and leads
to shortness of breath as the body cannot
take in enough oxygen.
The tumour uses lots of nutrients
and energy to grow, which
causes weight loss.
This is inflammation
of the lungs.
Cigarette smoke damages the cilia and
causes the goblet cells to secrete more
mucus and it accumulates in the lungs
and causes coughing to try and remove it.
Microorganisms multiply in the mucus and
cause lung infections that lead to
inflammation and decreases gas
COPD is a group of diseases that
involve permanent airflow
reduction. Chronic Bronchitis is a
type of COPD.
A lung disease caused by smoking/prolonged
exposure to air pollution where foreign
particles get trapped in the alveoli.
This causes inflammation which encourages the
presence of phagocytes. They produce an
enzyme which breaks down the elastic wall of
the alveoli, destroying their walls and elasticity.
This reduces the surface area
of the lungs, decreasing the
rate of gaseous exchange.
Symptoms include: shortness
of breath and wheezing.
Sample size - large/small? The bigger
it is, the more reliable the results.
Type of study? E.g.
questionnaires leave room
for people to lie.
People used? Depending on
the people, bias could occur.
Variables should be as
controlled as possible, i.e. all the
participants should be matched
in some way.