Gas Exchange

Question 1

What is the trachea?

Answer 1

• Air passes into the lungs through a trube called treachea.

Adaptation: Rings of Cartillage~ prevents the trachea from collpasing during inhalation.

Question 2

What are bronchi?

Answer 2

• Tranchea splits into two smaller tubes called bronchi.
• ## One passing to each lungs.

Question 3

What are bronchioles?

Answer 3

• Bronchi sub-divide into smaller tubes.

Question 4

What are alveloi?

Answer 4

• Bronchioles end in tiny air sacs called alveoli.
• Where gases diffuse in and out of the blood stream.
• Oxygen into the air diffuse into the blood stream.
• Carbon Dioxide diffuses out of the blood stream.

Question 5

How are alveoli adapted for gas exchange?

Answer 5

• Millions of alveoli mean that lungs have a huge surface area.
• Very thin walls: Diffusion pathway is very short.
• Very Good Blood supply: When oxygen diffuses into the blood stream it is rapidly removed.
• Ensures that the concentration gradient is steep.

Question 6

By breathing…what happens?

Answer 6

• Increases rate of diffusion.
• Breathing brings fresh oxygen into the alveoli and takes away co2.
• Makes concentration gradient high.
• Increases rate of diffusuion.