In this chapter of I/GCSE Biology, we will discuss about Breathing and Gas exchange (Part 1).
Humans
Describe the structure of the thorax, including the:
- ribs
- intercostal muscles,
- diaphragm,
- trachea,
- bronchi
- bronchioles,
- alveoli and
- pleural membranes
The Purpose of Breathing
a) To remove carbon dioxide from the body into the air outside.
This carbon dioxide is generated from respiration. The greater the rate of respiration, the more carbon dioxide is generated so the faster the rate of breathing.
b) To move oxygen into the body from the air outside.
The greater the rate of AEROBIC respiration, the higher the demand for oxygen
Refer to I/GCSE Biology, The rate of air flow in and out of the lungs is controlled in 2 ways:-
- Number of breaths per minute (breathing rate)
- The deepness of each breath (the deeper the breath, the greater the volume of air moved per breath).
Anatomy of Lungs
Key structures
- Ribs, intercostal muscles, diaphragm, lungs.
- Trachea (windpipe), Bronchus (bronchi), Bronchioles, alveolus (alveoli)
- Pleural membranes, pleural cavity.
When it comes to I/GCSE Biology, The zone of the body between the neck and the bottom of the ribs is known as the thorax. The major organs in the thorax are the heart and lungs. The lungs and associated airways allow us to breathe.
In the head the airways consist of the mouth and nasal passages. Air and food has a common passage in the throat. The airways from the neck into the lungs have the following divisions:
- Larynx - speech and sound generation.
- Trachea or windpipe – carries air from the throat to the bronchi.
- Two tubes that are each known as a bronchus, plural bronchi – carry air into the bronchioles within the lungs.
- Bronchioles which are subdivisions of each bronchus.
- Alveoli which are sacs at the end of the airways, the sites of gas exchange.
- Pleural membranes – attached to inside wall of the thorax and the lungs and prevent friction as the lungs expand and contract.
That's end of part 1~ Part 2 gogogo!
