GCSE PEThe Respiratory System

Air passes through the respiratory system in this order; Trachea (Windpipe)

Air passes through the nose or mouth and then on to the trachea.

Layout of the Respiratory System

Bronchi

The trachea splits into two tubes called bronchi (each one is a bronchus) – one going to each lung.

Layout of the Respiratory System

Bronchioles

The bronchi split into progressively smaller tubes called bronchioles.

Layout of the Respiratory System

Alveoli

The bronchioles finally end at small bags called alveoli (each one is an alveolus) where gas exchange takes place

Layout of the Respiratory System

The area inside the chest containing the lungs, heart and all the other bits is the chest cavity.

Layout of the Respiratory System

Takes place in the alveoli1. Blood collects CO2 as it travels around the

body and takes it to the lungs2. CO2 moves from the blood into the alveoli3. Oxygen breathed in from the air moves

across from the alveoli into the red blood cells

4. Red blood cells carry the oxygen around the body and deliver it to where it’s needed

Gas Exchange

When you breathe normally, you only breathe a small amount of air in or out

The most air you could possibly breathe in or out is called your vital capacity

You can improve your vital capacity through exercise

Vital Capacity

Effects of Exercise on the Respiratory System

The Respiratory System

During exercise, you need to increase the oxygen supply to your muscles, so; You breathe more quickly. You breathe more deeply, taking in a larger volume of

air. If you are doing anaerobic activity, your muscles build

up lactic acid. The amount of oxygen needed to get rid of this is called the oxygen debt. To repay this debt, you continue to breathe heavily for a while after you stop exercising.

Short-Term Effects

Muscles around the chest cavity get stronger, so the chest cavity becomes larger.

Larger chest cavity = Increased vital capacity.

Increased vital capacity = More O2 into lungs and bloodstream per breath.

This all means that you have better O2 supply to the body, meaning you should be able to exercise for longer.

Long-Term Effects

Can lead to lung diseases like cancer, bronchitis and emphysema.

Cigarette smoke contains tar, which clogs up alveoli and makes it harder for gas exchange to take place. Eventually, they will collapse and stop working.

Once this has happened, even if tar is removed and alveoli are repaired, they will never be as efficient.

Nicotine causes blood vessels to tighten, slowing blood flow in the lungs and making gas exchange less efficient.

Negative Effects of Smoking