New
New
Year 9

The gas exchange system in healthy humans

I can describe the function and structures of the human gas exchange system in healthy humans.

New
New
Year 9

The gas exchange system in healthy humans

I can describe the function and structures of the human gas exchange system in healthy humans.

Lesson details

Key learning points

  1. Why oxygen needs to be absorbed into, and carbon dioxide needs to be removed from, the human body.
  2. The function and structures of the lungs in healthy humans.
  3. The mechanism of breathing, including the role of muscles, to move air in and out of the lungs.
  4. Adaptations of healthy lungs that increase the amount of gas exchange.
  5. Detailed structure of the alveoli in healthy human lungs.

Common misconception

Believing that we need oxygen to breathe.

We breathe to get oxygen into our bodies so cells can use it as fuel for respiration.

Keywords

  • Gas exchange - The process of oxygen diffusing from the lungs into the blood, and carbon dioxide diffusing from the blood to the lungs.

  • Breathing - The process in which air moves in and out of the lungs.

  • Ventilation - Movement of air in and out of the lungs.

  • Lungs - A pair of organs in the respiratory system of humans, and many animals, that provide a gas exchange surface for oxygen and carbon dioxide.

  • Alveoli - Tiny air sacs in the lungs that carry out gas exchange.

Encourage students to talk about what happens to their ribs when they breathe in and what this might mean for the volume inside the thorax. Draw some particle diagrams on the board to model pressure change.
Teacher tip

Content guidance

  • Depiction or discussion of sensitive content
  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
What is the scientific name for the windpipe?
Correct Answer: trachea
Q2.
Which measurements do you need to calculate breathing rate?
Correct answer: number of breaths
pulse
Correct answer: time
volume of air
Q3.
Exercise will breathing rate.
Correct Answer: increase
Q4.
Which image shows a mitochondrion?
An image in a quiz
A
B
Correct answer: C
Q5.
The surface area of the rectangle is cm².
An image in a quiz
Correct Answer: 168
Q6.
If the volume of a box gets smaller, the pressure inside will ...
Correct answer: increase
decrease
stay the same

6 Questions

Q1.
True or false? The small air sacs found in the lungs are known as bronchioles.
true
Correct answer: false
Q2.
What are the rings around the trachea made from?
bone
muscle
Correct answer: cartilage
Q3.
During the intercostal muscles and diaphragm contract.
Correct Answer: inhalation
Q4.
What do alveoli have to maintain a concentration gradient?
An image in a quiz
Correct answer: a good blood supply
large surface area
a high temperature
Q5.
The lungs need to excrete as it is a waste product of respiration.
Correct Answer: carbon dioxide, CO2
Q6.
Put the statements in the right order to describe inhalation.
An image in a quiz
1 - the intercostal muscles contract
2 - the ribcage moves upwards and outwards and the diaphragm contracts and flattens
3 - volume increases
4 - pressure decreases
5 - air moves in