The smart way to improve grades

Comprehensive & curriculum aligned

Affordable pricing from £10/month

What Happens in the Lungs?

This worksheet will test a student's understanding of what happens in the lungs.

'What Happens in the Lungs?' worksheet

Key stage:  KS 3

Curriculum topic:  Biology: Structure and Function of Living Organisms

Curriculum subtopic:  Gas Exchange Systems (Breathing)

Difficulty level:  

down

Worksheet Overview

QUESTION 1 of 10

From a young age, we are taught to think of our lungs as two balloons, inflating and deflating as we breathe in and out. Our lungs are, in fact, far more complex.
 
 
So how does the air get into the lungs?


As the air travels down the trachea it is forced to branch off into the two lungs through the bronchi (bronchi is simply the plural for bronchus, as shown in the diagram below):
 
 


 
 
Once the air passes into the lungs through the initial bronchi, it is then met by more branches. The branches then get smaller and smaller until they are the same thickness as a hair! These tiny branches are called bronchioles; but the story of the lungs does not end here, as at the end of each bronchiole there are tiny air sacs called alveoli. 
 
 
So what happens in the alveoli?

 
Inside the alveoli, oxygen is absorbed into the blood and carbon dioxide is removed. This exchange of gases is called diffusion
 
The alveoli provide the lungs with a large surface area for diffusion to take place on and the thin, moist walls are the perfect place for it. Each alveolus is also surrounded by lots of tiny blood vessels called capillaries, that carry blood to and from the lungs.
 
As the blood passes by the surface of the alveoli, waste carbon dioxide diffuses out of the blood and into the alveoli. 
At the same time, oxygen from the alveoli diffuses into the blood supply where it is then carried around the rest of the body by red blood cells.

In the answer box below, write the word which completes this sentence:

 

When we breathe in, the air travels from our nose and mouth towards our lungs down the ______________.

Select the word which completes this sentence:

 

Air enters the lungs through branches called _________.

trachea

bronchi

bronchioles

twigs

What are found at the end of each bronchiole? 

lungs

the liver

alveoli

kidneys

Which of the following gases is needed in our body and which is a waste gas that needs to be removed? 

 

 Useful gasWaste gas
Oxygen
Carbon Dioxide

The exchange of gases in the alveoli takes place by which process?

respiration

osmosis

diffusion

breathing

Which of the following features apply to alveoli?

 

thick, dry walls

thin, moist walls

a good blood supply

a good water supply

a large surface area

a small surface area

Oxgyen diffuses through the walls of the alveoli into what type of cells?

muscle cells

red blood cells

white blood cells

nerve cells

The diagram below shows the process of gaseous exchange in an alveolus. Using the information, in addition to your knowledge about breathing in humans, answer the question below:

 

 

Where would you find deoxygenated blood?

pulmonary artery

pulmonary vein

The diagram below shows the process of gaseous exchange in an alveolus. Using the information, in addition to your knowledge about breathing in humans, answer the question below:

 

 

 

Where would you find oxygenated blood?

pulmonary artery

pulmonary vein

The diagram below shows the process of gaseous exchange in an alveolus. Using the information, in addition to your knowledge about breathing in humans, answer the question below. 

 

 

Match up the correct part/process with its function/description. If you can't read the entire description, hover your mouse over the box.

Column A

Column B

capillary
allows effective diffusion
ventilation
how gas exchange takes place
epithelium
lining of alveolus
pulmonary artery
waste gas
pulmonary vein
carries deoxygenated blood
red blood cell
carries oxygen
diffusion
a gas used in respiration
carbon dioxide
supply of air to the lungs
oxygen
brings blood to alveolus
film of moisture
carries oxygenated blood
  • Question 1

In the answer box below, write the word which completes this sentence:

 

When we breathe in, the air travels from our nose and mouth towards our lungs down the ______________.

CORRECT ANSWER
trachea
EDDIE SAYS
The trachea is the wind pipe, which air travels down to get to the lungs.
  • Question 2

Select the word which completes this sentence:

 

Air enters the lungs through branches called _________.

CORRECT ANSWER
bronchi
EDDIE SAYS
The bronchi are the major air passages which divert air from the trachea into the lungs.
  • Question 3

What are found at the end of each bronchiole? 

CORRECT ANSWER
alveoli
EDDIE SAYS
Alveoli are the tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place.
  • Question 4

Which of the following gases is needed in our body and which is a waste gas that needs to be removed? 

 

CORRECT ANSWER
 Useful gasWaste gas
Oxygen
Carbon Dioxide
EDDIE SAYS
Carbon dioxide is not needed in our body and is therefore expelled when we breath out. We need oxygen for respiration.
  • Question 5

The exchange of gases in the alveoli takes place by which process?

CORRECT ANSWER
diffusion
EDDIE SAYS
The process used in the exchange of gases (oxygen and carbon dioxide) in the alveoli is 'diffusion'.
This means the movement of molecules from where they are at a high concentration (i.e. oxygen in the alveoli) to a lower concentration (i.e. oxygen in the blood).
  • Question 6

Which of the following features apply to alveoli?

 

CORRECT ANSWER
thin, moist walls
a good blood supply
a large surface area
EDDIE SAYS
The alveoli have thin, moist walls. They provide the lungs with a large surface area for diffusion to take place, and they are surrounded by lots of tiny blood vessels which carry blood to and from the lungs.
  • Question 7

Oxgyen diffuses through the walls of the alveoli into what type of cells?

CORRECT ANSWER
red blood cells
EDDIE SAYS
Oxygen diffuses through the walls of the alveoli into the red blood cells, which then travel all around the body.
  • Question 8

The diagram below shows the process of gaseous exchange in an alveolus. Using the information, in addition to your knowledge about breathing in humans, answer the question below:

 

 

Where would you find deoxygenated blood?

CORRECT ANSWER
pulmonary artery
EDDIE SAYS
The pulmonary artery will bring deoxygenated blood to the alveoli to get more oxygen before sending it around the rest of the body.
  • Question 9

The diagram below shows the process of gaseous exchange in an alveolus. Using the information, in addition to your knowledge about breathing in humans, answer the question below:

 

 

 

Where would you find oxygenated blood?

CORRECT ANSWER
pulmonary vein
EDDIE SAYS
The pulmonary artery carries deoxygenated blood from the heart to the lungs where the blood can pick up oxygen.
  • Question 10

The diagram below shows the process of gaseous exchange in an alveolus. Using the information, in addition to your knowledge about breathing in humans, answer the question below. 

 

 

Match up the correct part/process with its function/description. If you can't read the entire description, hover your mouse over the box.

CORRECT ANSWER

Column A

Column B

capillary
brings blood to alveolus
ventilation
supply of air to the lungs
epithelium
lining of alveolus
pulmonary artery
carries deoxygenated blood
pulmonary vein
carries oxygenated blood
red blood cell
carries oxygen
diffusion
how gas exchange takes place
carbon dioxide
waste gas
oxygen
a gas used in respiration
film of moisture
allows effective diffusion
EDDIE SAYS
The pulmonary vein carries oxygenated blood away from the lungs back to the heart where it will get pumped around the rest of the body.
---- OR ----

Sign up for a £1 trial so you can track and measure your child's progress on this activity.

What is EdPlace?

We're your National Curriculum aligned online education content provider helping each child succeed in English, maths and science from year 1 to GCSE. With an EdPlace account you’ll be able to track and measure progress, helping each child achieve their best. We build confidence and attainment by personalising each child’s learning at a level that suits them.

Start your £1 trial

Start your trial for £1