What happens when you breathe BBC Bitesize?
When we breathe out, the chest muscles move down and inwards. The diaphragm moves up. This squeeze the lungs and forces air out. Carbon dioxide from the alveoli flows up through the lungs and out through the mouth and nose.
What is the structure of the lungs BBC Bitesize?
The structure of the respiratory system The lungs are enclosed in the thorax, surrounded and protected by 12 pairs of ribs. The ribs are moved by two sets of intercostal muscles . There is a muscular diaphragm below the lungs. The lungs are sealed within two airtight pleural membranes .
How do we ventilate our lungs?
Ventilation, or breathing, is the movement of air through the conducting passages between the atmosphere and the lungs. The air moves through the passages because of pressure gradients that are produced by contraction of the diaphragm and thoracic muscles.
How does photosynthesis work BBC Bitesize?
Photosynthesis takes place inside plant cells in small objects called chloroplasts . Plants get carbon dioxide from the air through their leaves, and water from the ground through their roots. Light energy comes from the Sun. The oxygen produced is released into the air from the leaves.
What do the bronchioles do BBC Bitesize?
Each bronchus branches out into smaller tubes called bronchioles. Air travels through these bronchioles. At the end of the bronchioles, the air enters one of the many millions of alveoli where gaseous exchange takes place.
What is ventilation breathing?
How is a lung model used to demonstrate breathing?
A lung model can be used to demonstrate the process of breathing. The balloons represent the lungs, the glass jar represents the thorax and a rubber sheet represents the diaphragm. The lung model shows inhalation: When the diaphragm (rubber sheet) moves down, the volume inside the glass jar (thorax) increases.
Which is the correct way to describe the mechanism of breathing?
The mechanism of breathing is described using an animation: active inhalation and passive exhalation. Students could use this clip to supplement the demonstration of a model set of lungs in a bell jar, or as an alternative to this classic demonstration.
How are balloons used to demonstrate the process of breathing?
A lung model can be used to demonstrate the process of breathing. The balloons represent the lungs, the glass jar represents the thorax and a rubber sheet represents the diaphragm. When the diaphragm (rubber sheet) moves down, the volume inside the glass jar (thorax) increases. This increase in volume causes a decrease in pressure.
How is the respiratory system adapted for gas exchange?
The respiratory system is adapted for gas exchange. We need to get oxygen from the air into the blood, and we need to remove waste carbon dioxide from the blood into the air. Moving gases like this is called gas exchange.