Smoking
Learning objective:
To know how a healthy respiratory
system works, and how smoking
effects it
Smoking
• Starter: Complete the following passage:
Deoxygenated blood returns to the heart via the ______. It enters the
___ ____. When this is full the blood flows through the tricuspid
valve into the ____ ____. When the heart contracts the blood is
forced out of the heart through the pulmonary ______, to the
_______, where Carbon dioxide is passed into the air sacs and
_______ diffuses into the blood. It returns to the _____ side of the
heart via the pulmonary_____. It enters the ___ ___. When this is
full it flows through the mitrial valve into the ___ ____. When the
heart contracts the blood is forced out of the heart under ____
pressure through the _______.
Key Words: oxygen, right ventricle, vena cava, left atrium, artery, vein,
aorta, left ventricle, right atrium, lungs, left, high.
Respiratory System
• What does the respiratory system do? What parts does it consist of?
• The respiratory system contains the organs that allow us to get the
oxygen we need and to remove the waste carbon dioxide

It consists of: –
Lungs
– Tubes leading from the lungs to the mouth and nose
– Various structures in the chest that allow air to move
in and out of the lungs
Respiratory System
• Movements of the ribs, rib muscles and diaphragm allow air into and
out of the lungs: this is called breathing or ventilation
• When we breathe in, we inhale
• When we breathe out, we exhale

Air passes between the lungs and the
outside of the body through the
trachea
 The trachea divides into two bronchi,
with one bronchus for each lung
 Each bronchus divides further in the
lungs into smaller tubes called
bronchioles
 At the end of each bronchiole, there is
a group of tiny air sacs called alveoli
Breathing / Ventilation
Breathing in (inhale) - ribs move up and out, diaphragm contracts (pulled down)
Breathing out (exhale) - ribs move down and in, diaphragm relaxes (moves upward)
Breathing
• Complete the breathing
worksheet - stick this in your book
(plus all other work)
Breathing
Gas Exchange
• For respiration to occur, we need to get oxygen from the air to the
blood, and remove waste carbon dioxide from the blood
• Alveoli in the lungs are adapted to make gas exchange happen easily
and efficiently: they cause the lungs to have a very large surface
area; are moist with thin walls; and have many capillaries
The gases move via diffusion (net [high] to [low])
Smoking
• What are the problems of smoking?
• Smoking is very harmful to health, causing ~80% of deaths from lung
cancer, bronchitis and emphysema, and ~20% of deaths from heart
disease in the UK
• Tobacco smoke contains many harmful substances, including: tar;
nicotine; and carbon monoxide
• Second hand smoke is just as dangerous! You’ll get all the health
problems are smoker will…
Smoking Practical
Smoking Problems
• Carbon monoxide – a poisonous gas that reduces the amount of
oxygen that red blood cells carry around the body
• Tar – a brown, sticky substance that consists of tiny particles and is
formed when tobacco smoke condenses. Deposited in the lungs, it
coats the surface of the alveoli
• Nicotine – an addictive drug that affects the central nervous system,
increasing the heart rate and narrowing the blood vessels, causing
high blood pressure
Normal lung (left) verses smokers lung (right)
Cilia
• There are also specialised cells in the lining of the breathing tubes
which produce a sticky mucus to trap dirt and microbes
• Specialised cells called cilia help to move this mucus out of the lungs
• Smoking can damage these delicate cells (hot smoke and tar) and
they are less effective
• This is why smokers cough a lot, trying to move this mucus
Cilia
Task
• Your task is to give your opinion about the smoking ban - is it a good
or bad thing?
• Either way, you need to include the affects smoke has on the
respiratory system, and the associated health problems this can lead
to…