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…