Lungs & Gas Exchange

• What is the primary function of the lungs?

  To get oxygen from the air into the bloodstream
• What process do all cells need to carry out to function?

  Cellular respiration
• How does air enter the lungs?

  Through the mouth or nose and trachea
• What is the trachea also known as?

  The windpipe
• What are the two main branches of the trachea called?

  Bronchi
• What are the small structures at the end of bronchioles called?

  Alveoli
• How are alveoli arranged?

  Like bunches of grapes
• Why do alveoli have a thin cell layer?

  To create a short diffusion pathway
• What is a key feature of alveoli that aids gas exchange?

  They have a large surface area
• 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 for diffusion
• What happens to hemoglobin in red blood cells in the lungs?

  It gives up oxygen to the tissues
• What color represents deoxygenated blood in the video?

  Blue
• What is the concentration gradient for oxygen in the alveoli?

  Higher in the alveoli than in the blood
• How is carbon dioxide transported in the blood?

  Dissolved in the blood plasma
• What happens to carbon dioxide during gas exchange?

  It diffuses from blood into the alveoli
• What happens to the blood during gas exchange?

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

  Divide breaths taken by time in minutes
• If you took 42 breaths in three 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
• What is the process of gas exchange in the lungs?

  1. Oxygen diffuses from alveoli to blood
  2. Carbon dioxide diffuses from blood to alveoli
  3. Oxygenated blood is transported to the body
  4. Deoxygenated blood returns to the lungs
• What happens to breathing rate during exercise?

  • Breathing rate increases
  • More oxygen is needed for energy