Biology y10

• What happens to air after it passes through the trachea?

  It divides between the two bronchi and further into bronchioles
• What are the small sacs in the lungs called?

  Alveoli
• How are alveoli adapted for gas exchange?

  They have a thin cell layer and a large surface area
• What is the significance of the short diffusion pathway in alveoli?

  It increases the rate of diffusion for gases
• How many alveoli do adults have approximately?

  Hundreds of millions
• What would happen if all alveoli were spread out flat?

  They would cover half a tennis court
• Why are the walls of alveoli moist?

  To allow gases to dissolve and increase diffusion rate
• What color represents deoxygenated blood in the video?

  Blue
• How does the concentration gradient affect gas exchange in the alveoli?

  Oxygen diffuses from alveoli to blood due to a higher concentration in alveoli
• What happens to blood during gas exchange in the lungs?

  Deoxygenated blood enters the capillaries and oxygenated blood leaves
• How can you calculate breathing rate?

  By dividing the number of breaths taken by the time in minutes
• If you took 42 breaths in 3 minutes, what is your breathing rate?

  14 breaths per minute
• What are the key features of alveoli that facilitate gas exchange?

  • One layer of thin cells
  • Large surface area
  • Moist walls for gas dissolution
• Describe the process of gas exchange in the alveoli.

  1. Oxygen diffuses from alveoli (high concentration) to blood (low concentration).
  2. Carbon dioxide diffuses from blood (high concentration) to alveoli (low concentration).
  3. Oxygenated blood is transported to the body, while carbon dioxide is exhaled.