the break down

of glucose

to release energy

Use the words above to write a word equation for respiration

What do you know????

BRONCHUS

BRONCHIOLE

MUSCLE

AIR SAC

LEFT LUNG

DIAPHRAGM

TRACHEA

RIB

BRONCHUS

Breathe in Breathe outDiaphragm Contracts Relaxes

Muscles between ribs

Contract Relax

Rib cage Moves up & out Moves down & in

Volume of chest cavity

Increases Decreases

Pressure in chest cavity

Decreases Increases

Air Moves in to lungs Pushed out of lungs

Breathing movements

How do gases get into our blood from the air?

• Gas exchange takes place in the alveoli, the little round structures (‘air sacs’) at the end of the bronchioles in our lungs.

How do gases get into our blood from the air?

• Carbon dioxide leaves the blood and enters the alveoli, while oxygen leaves the alveoli and enters the bloodstream.

• This movement of gases between the alveoli and blood is called gas exchange.

• Our lungs contain millions of alveoli. Each alveolus is wrapped up in tiny blood vessels called capillaries.

The net around the oranges is like the network of capillaries around the alveoli

capillary

Carbon dioxide enters the alveolus

Oxygen enters the bloodstream

Complete the diagram and stick it into your notes

Carbon dioxide is breathed outOxygen is breathed in

How big are your lungs?

• The bigger the lungs are the more oxygen can enter and carbon dioxide can leave the lungs.

• To allow the maximum amount of oxygen and carbon dioxide to enter and leave the lungs, their size is extremely important.

• The size of the lungs is measured as lung volume.

• Values for lung volume are sometimes taken as a measure of lung function i.e. how well the lungs are working.

• Reduced lung volume is a feature of the condition of asthma, that affects many people.

Measuring lung volume

• You can measure lung volume using the information on P113 of the Y9 textbook. Plot the results for lung volume for each person in your class against their height. Is there a link?

• Your teacher may also be able to show you a ‘peak flow meter’, which lets you measure lung function.

Asthma animation

Why worry about asthma?• What are the symptoms of an asthma attack?• The person may struggle to breathe.

• If a person has an asthma attack, what important gas may be decreased in their body?

• Oxygen

• Why is an asthma attack dangerous?• The person may not get enough oxygen to allow their cells to

respire.

• Why is respiration a vital process in every cell?• Respiration provides energy for all the cell’s activities that keep

us alive.

Summa r y