Topic B (Breathing and Gas Exchange) Flashcards
Breathing
Movement carried out by muscle to draw air in and out of the lungs
Gas exchange
The process of exchanging gases between the air in the lungs and the bloodstream
Diffusion
The movement of particles from an area of high concentration to an area of low concentration until an equilibrium is reached. In a fluid
Respiration
The chemical reaction taking place in all living cells to release energy from glucose
What is the percentage of Nitrogen gas in the inhaled/exhaled air?
78/78
What is the percentage of Oxygen gas in the inhaled/exhaled air?
21/18
What is the percentage of Carbon dioxide gas in the inhaled/exhaled air?
0.04/4
What is the percentage of Water vapour in the inhaled/exhaled air?
little/more
What is the function of Diaphragm
Increases the volume of the chest cavity when it contracts during inhalation
What is the function of Cartilage rings
Keep airways open during breathing
What is the function of Cilia and mucus
Trap dust
What is the function of Intercostal muscles
Make the rib cage move out when they contract
What is the function of Pleural membrane
Keep the chest cavity air tight
What is the function of Alveoli and ends of bronchi
Allow gaseous exchange to occur
What happens when I breathe in? (5 including changes in pressure)
1) The external intercostal contract moving the ribs upwards and outwards
2) The diaphragm contracts and flattens
3) Volume in the thorax has increased, causing the pressure in there to decrease
4) Pressure in the lungs is lower than outside
5) Causes air to rush into the lungs
What happens when I breathe out? (5 including changes in pressure)
1) The external intercostal muscles relax, allowing the ribs to move back down
2) The diaphragm relaxes and returns to its original shape. This means it pushes up on the lungs
3) Volume in the thorax has decreased, causing the pressure to increase
4) Pressure outside is now lower than in the lungs
5) Causes the air to rush out
Adaptations of lungs for gaseous exchange (4)
1) Alveoli have a large surface area 2) Alveoli and capillaries have a 1 cell thick wall 3) Each alveolus is surrounded by capillaries 4) Thin film of water on inside of alveoli
Where are Pleural membranes?
Around the lungs
Where are Cartilage rings?
In the trachea
Where is Larynx?
At the top of the trachea
Ventilation
The movement of air between the lungs and the environment, achieved by pressure changes in the thorax
Adaptations of the lungs for ventilation (3)
1) Elastic tissue 2) Cartilage rings in trachea 3) Air tight thorax
Gaseous exchange
The diffusion of oxygen and carbon dioxide down concentration gradient occurs in capillaries, lungs and organs
Oxygenated blood
Blood that has a high oxygen concentration, just come out of alveolus
