Gas Exchange Humans Flashcards
What do all aerobic organisms require?
- • Supply of oxygen to release energy in the form of ATP during respiration.
- Removal of carbon dioxide produced in the process
Why is the volume of oxygen absorbed, and carbon dioxide removed large in mammals?
- They are 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 special gas exchange surface have mammals evolved?
Lungs
Why were lungs evolved?
To ensure efficient gas exchange between the air and their blood.
What is the site of gas exchange in mammals?
Lungs
Why are lungs located inside the body?
- Air is not dense enough to support and protect lungs as they are delicate
- Body would lose a large amount of water and dry out
What are the lungs supported/protected by?
The Rib Cage
How is the air in the lungs constantly replenished?
Lungs are ventilated by a tidal stream of air, ensuring that the air within them is constantly replenished.
What are the main parts of the gas exchange system of humans?
- Alveoli
- Bronchioles
- Bronchi
- Trachea
- Lungs
What are the lungs?
Pair of structures made up a series of branched tubules, which end in tiny air sacs.
What is the trachea?
- Flexible airway that is supported by rings of cartilage.
* Tracheal walls are made up of muscle, which is lined with cilia-ted epithelium and goblet cells
Why is cartilage necessary in the trachea?
Prevents the trachea collapsing when the air pressure inside falls when breathing in
What are the bornchi?
• Two divisions of the trachea, each leads to one lung
What is the purpose of the bronchi?
• Produce mucus to trap dirt particles and have cilia that move the dirt mucus towards the throat.
What are the bronchi supported by?
- Bronchi are supported by cartilage.
* Amount of cartilage is reduced as the size of bronchi decreases
What are the bronchioles?
- Series of branching subdivisions of the bronchi
* Walls are made up up of muscle lined with epithelial cells.
What is the purpose of the muscle wall in bronchioles?
Allows them to constrict, so that they can control the flow of air in and out of the alveoli.
What are the alveoli?
- Minute air sacs at the end of bronchioles
- There is collagen and elastic fibres presen
- The alveoli are lined with epithelium
What is the purpose of elastic fibres in alveoli?
They allow the alveoli to stretch as they fill with air when breathing in
• They then spring away when exhaling in order to expel the carbon dioxide rich air.
What is the gas exchange surface in lungs?
Alveoli
What do humans require oxygen for?
- Humans require oxygen in the blood for respiration.
* They also need to get rid of CO2 which is a product of respiring cells.
