Bronchial Tree

• • Below your larynx is your trachea
  • trachea bifurcates into your right and left main bronchus at a point called the carina
  • right main bronchus provides right lung and left main bronchus provides left lung

  
• • right main bronchus comes off at an angle of 20 - 30 degrees
  • left main bronchus comes off at an angle of 45 - 50 degrees, so is more horizontal

  
• • the main bronchus divides into the lobar bronchus which supplies each lobe of the lungs
  • each lobar bronchus divides into segmental bronchus which supply their own bronchopulmonary segment
  • 23 total divisions, the final and smallest one being the terminal bronchioles in the conducting zone, where gas is conducted into our alveoli (no gas exchange occurs in this zone)

  
• • gas exchange occurs at the respiratory bronchioles which is distal to the terminal bronchioles
  • respiratory bronchioles are part airway and part alveoli
  • respiratory bronchioles lead into alveoli

  
• • theres a lot of smooth muscles through the conducting zone, so if it contracts the airway becomes narrower - bronchoconstriction
• • hyaline cartilage acts as a supporting structure for the airways
  • there is less amounts as you go down the smaller airways
• • the smaller airways lack cartilage but still have a high amount of smooth muscle
  • this means that contraction/relaxation can affect diameter of airways therefore affects resistance to air flow