Structure Of The Human Gas-Exchange System Flashcards
Why does carbon dioxide need to be removed?
As it builds up it could become harmful to the body.
Why is the volume of oxygen that has to be absorbed and the volume of carbon dioxide that must be removed large in mammals?
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.
What is the name of the specialised gas exchange surface in mammals?
Lungs
What do lungs ensure?
Efficient gas exchange between the air and the blood.
Why are the lungs located inside the body?
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.
What are the lungs supported and protected by?
The ribcage.
Can the ribs be moved?
Yes, they can be moved by the muscles between them.
What are the lungs ventilated by?
A tidal stream of air.
What ensures that the air within the lungs is constantly replenished?
The tidal stream of air.
What are the five main parts of the human gas exchange system?
Lungs Trachea Bronchi Bronchioles Alveoli
What are the lungs?
A pair of lobed structures.
What are the lungs made up of?
A series of highly branched tubules called bronchioles.
What do bronchioles end in?
Air sacs known as alveoli.
What is the trachea?
A flexible aireway that is supported by rings of cartilage.
What does the cartilage prevents the trachea from doing?
It prevents it from collapsing.
What happens to the air pressure inside the trachea when breathing in?
The pressure falls.
What are the tracheal walls made up of?
Muscle, lined with ciliated epithelium and goblet cells.
What are the bronchi divisions of?
They are two divisions of the trachea.
Where do the bronchi lead to?
Each bronchi leads to one lung.
What is the structure of the bronchi similar to?
The trachea
What do the bronchi and trachea both produce?
They both produce mucus and have cilia.
What is the purpose of the mucus in the bronchi and trachea?
To trap dirt particles.
What is the purpose of the cilia in the bronchi and trachea?
To move the dirt-laden mucus towards the throat.
What are the larger bronchi supported by?
Cartilage
What happens is the bronchi get smaller?
The amount of supportive cartilage is reduced.
What are the bronchioles?
These are a series of divisions from the bronchi.
What are the walls of the bronchioles made of?
They are muscle lined with epithelial cells.
What does the muscle allow the bronchioles to do?
It allows them to constrict so that they can control the flow of air in and out of the alveoli.
Where are the alveoli found?
At the end of the bronchioles.
What can be found between the alveoli?
Collagen and elastic fibres.
What are the alveoli lined with?
Epithelium
What do the elastic fibres allow the alveoli to do?
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.
What is the gas exchange surface?
The alveolar membrane.
