Respiratory System
What is respiration?
Respiration is the chemical process that releases energy from glucose in cells.
What happens during inhalation?
The diaphragm contracts and flattens, the ribs move upwards and outwards, chest volume increases, and air enters the lungs.
Which gas moves from the blood into the alveoli?
Carbon dioxide
Why does air leave the lungs during exhalation?
The pressure inside the lungs becomes higher than the pressure outside, so air moves out.
What is breathing
Breathing is the movement of air into and out of the lungs.
What happens during exhalation?
The diaphragm relaxes and becomes dome-shaped, the ribs move downwards and inwards, chest volume decreases, and air leaves the lungs.
Why does oxygen move from the alveoli into the blood?
Oxygen concentration is higher in the alveoli than in the blood, so oxygen diffuses into the blood.
Why does the volume of the chest cavity increase during inhalation?
The diaphragm contracts and flattens while the external intercostal muscles contract, moving the ribs upwards and outwards. This increases the volume of the chest cavity.
What is the main function of the respiratory system?
To take in oxygen and remove carbon dioxide from the body.
What happens to the pressure inside the lungs during inhalation?
: It decreases.
Why does carbon dioxide move from the blood into the alveoli?
Carbon dioxide concentration is higher in the blood than in the alveoli, so it diffuses into the alveoli.
Explain how an increase in chest volume causes air to enter the lungs.
ncreasing chest volume lowers the pressure inside the lungs. Air moves from the higher pressure outside the body to the lower pressure inside the lungs.
Name the main parts of the respiratory system.
Nose, trachea, bronchi, bronchioles, alveoli and lungs.
Why does air enter the lungs during inhalation?
the pressure inside the lungs becomes lower than the pressure outside, so air moves into the lungs
Why is the blood supply around the alveoli important?
It continuously carries oxygen away and brings carbon dioxide to the alveoli, maintaining a concentration gradient for gas exchange.
What happens to the diaphragm during inhalation, and why is this important?
The diaphragm contracts and flattens. This increases the volume of the chest cavity and lowers the pressure inside the lungs.
What is the function of the nose?
It allows air to enter and helps filter, warm and moisten the air.
Why does air leave the lungs during exhalation?
The pressure inside the lungs becomes higher than the pressure outside, so air moves out.
State three adaptations of alveoli for efficient gas exchange.
What happens to the diaphragm during exhalation?
The diaphragm relaxes and returns to its dome shape. This decreases the volume of the chest cavity and increases pressure inside the lungs.