Structure Of The Human Gas-Exchange System

Question 1

Why does carbon dioxide need to be removed?

Answer 1

As it builds up it could become harmful to the body.

Question 2

Why is the volume of oxygen that has to be absorbed and the volume of carbon dioxide that must be removed large in mammals?

Answer 2

They are relatively large organisms with a large volume of living cells.
They maintain a high body temperature which is related to them having high metabolic and respiratory rates.

Question 3

What is the name of the specialised gas exchange surface in mammals?

Answer 3

Lungs

Question 4

What do lungs ensure?

Answer 4

Efficient gas exchange between the air and the blood.

Question 5

Why are the lungs located inside the body?

Answer 5

There air is not dense enough to support and protect these delicate structures.
The body as a whole would otherwise it leaves a great deal of water and dry out.

Question 6

What are the lungs supported and protected by?

Answer 6

The ribcage.

Question 7

Can the ribs be moved?

Answer 7

Yes, they can be moved by the muscles between them.

Question 8

What are the lungs ventilated by?

Answer 8

A tidal stream of air.

Question 9

What ensures that the air within the lungs is constantly replenished?

Answer 9

The tidal stream of air.

Question 10

What are the five main parts of the human gas exchange system?

Answer 10

Lungs
Trachea
Bronchi
Bronchioles
Alveoli

Question 11

What are the lungs?

Answer 11

A pair of lobed structures.

Question 12

What are the lungs made up of?

Answer 12

A series of highly branched tubules called bronchioles.

Question 13

What do bronchioles end in?

Answer 13

Air sacs known as alveoli.

Question 14

What is the trachea?

Answer 14

A flexible aireway that is supported by rings of cartilage.

Question 15

What does the cartilage prevents the trachea from doing?

Answer 15

It prevents it from collapsing.

Question 16

What happens to the air pressure inside the trachea when breathing in?

Answer 16

The pressure falls.

Question 17

What are the tracheal walls made up of?

Answer 17

Muscle, lined with ciliated epithelium and goblet cells.

Question 18

What are the bronchi divisions of?

Answer 18

They are two divisions of the trachea.

Question 19

Where do the bronchi lead to?

Answer 19

Each bronchi leads to one lung.

Question 20

What is the structure of the bronchi similar to?

Answer 20

The trachea

Question 21

What do the bronchi and trachea both produce?

Answer 21

They both produce mucus and have cilia.

Question 22

What is the purpose of the mucus in the bronchi and trachea?

Answer 22

To trap dirt particles.

Question 23

What is the purpose of the cilia in the bronchi and trachea?

Answer 23

To move the dirt-laden mucus towards the throat.

Question 24

What are the larger bronchi supported by?

Answer 24

Cartilage

Question 25

What happens is the bronchi get smaller?

Answer 25

The amount of supportive cartilage is reduced.

Question 26

What are the bronchioles?

Answer 26

These are a series of divisions from the bronchi.

Question 27

What are the walls of the bronchioles made of?

Answer 27

They are muscle lined with epithelial cells.

Question 28

What does the muscle allow the bronchioles to do?

Answer 28

It allows them to constrict so that they can control the flow of air in and out of the alveoli.

Question 29

Where are the alveoli found?

Answer 29

At the end of the bronchioles.

Question 30

What can be found between the alveoli?

Answer 30

Collagen and elastic fibres.

Question 31

What are the alveoli lined with?

Answer 31

Epithelium

Question 32

What do the elastic fibres allow the alveoli to do?

Answer 32

Stretch as they fill with air when breathing in and then stretch back during briefing out in order to expel the carbon dioxide rich air.

Question 33

What is the gas exchange surface?

Answer 33

The alveolar membrane.