Structure of the human gas-exchange system Flashcards
What do aerobic organisms need and what’s the equation for aerobic respiration?
All aerobic organisms need a constant supply of oxygen to release energy in forms of ATP during respiration.
Glucose + O2 —-) CO2 + H2O + ATP.
Why do mammals need to absorb a large volume of O2 and needs to remove a large volume of CO2?
- Mammals are large organisms with a large volume of living cells.
- They need to maintain a high body temperature which is related to them having a high metabolic and respiratory rate.
Why are the lungs located inside the body?
- Air is not dense enough to support and protect these delicate structures.
- Otherwise, the body as a whole would lose water and dry out.
What supports and protects the lung?
The ribcage, the rib can be moved by the muscles located between them.
Describe the structure of the gas exchange system in human.
As you breathe in, the air enters the trachea (windpipe). The trachea splits into 2 bronchi - one bronchus leading to each lung.
Each bronchus then branches off into smaller tubes called bronchioles.
The bronchioles have small sacs of alveoli attached to them at the end.
Alveoli is where gases are exchanged.
The ribcage, intercostal muscles, and diaphragm all work together to move air in and out.
Describe what are the lungs.
The lungs are a pair of lobed structure made up of a series of highly branched tubules called bronchioles which has small air sacs called alveoli.
Describe what is the trachea.
It’s a flexible airway that is supported by rings of cartilage.
The cartilage prevents the trachea collapsing as air pressure inside falls when breathing in.
The tracheal walls are made up of muscles, lined with cilated epithelium and goblet cells.
Describe what are the bronchi.
Two divisions of the trachea, each leading to one lung.
They are similar in structure to the trachea and like the trachea, they also produce mucus to trap dirt particles and have cilia to move the dirt mucus towards the throat.
Describe what are the bronchioles.
Series of branching subdivisions of the bronchi.
Walls made up of muscles lined with epithelial cells.
The muscles allow them to control the flow of air in and out of the alveoli.
Describe what are the alveoli.
Tiny air sacs at the end of bronchioles.
Between alveoli are some collagen and elastic fibres. The elastic fibres allow the alveoli to stretch as they fill with air when breathing in. Then they spring back as it breath out to give out the CO2 rich air.
The alveoli are lined up with epithelium.
The alveolar membrane is the gas-exchange surface.
