Respiratory System
ICSE Class 6 · Biology · Chapter 5
What this chapter covers
- Why your body needs air
- Parts of the respiratory system
- Respiration and breathing: the difference
- Mechanism of breathing
- Common respiratory diseases
Key points
- The respiratory system takes in oxygen and gives out carbon dioxide.
- Air passes through the nose, pharynx, larynx, trachea, bronchi and lungs.
- The nose filters, warms and moistens the air.
- The larynx is the voice box; the trachea is held open by rings of cartilage.
- In the lungs, oxygen enters the blood and carbon dioxide leaves it.
- Breathing moves air in and out of the lungs; respiration releases energy from food inside cells.
- In inhalation the diaphragm moves down and the ribs move up and out; in exhalation they return.
- Exercise makes you breathe faster and more deeply.
- Asthma, bronchitis, pneumonia and tuberculosis are common respiratory diseases.
- Clean air, covering coughs, avoiding smoke and exercise keep the lungs healthy.
Questions answered
Name the main parts of the respiratory system in the order in which air passes through them.
Nose, pharynx, larynx, trachea, bronchi and lungs.
Give two ways in which the nose cleans the air you breathe in.
Hairs inside the nose trap dust, and sticky mucus traps dust and germs.
Why does the trachea not fold flat?
Its wall has rings of cartilage that keep it open all the time.
Which part of the respiratory system is called the voice box?
The larynx.
Give two differences between breathing and respiration.
Breathing moves air into and out of the lungs, but respiration breaks down food in the cells. Breathing does not release energy, but respiration does.
What happens to the diaphragm and the ribs during inhalation?
The diaphragm moves down and becomes flatter, and the ribs move upwards and outwards, so the chest becomes larger.
Why do you breathe faster after running a race?
Your muscles work harder and need more oxygen for energy, and more carbon dioxide has to be removed.
Name the respiratory disease that is spread through the air by germs and is prevented in babies by the BCG vaccine.
Tuberculosis (T.B.).