B6

Question 1

Respiratory system joruney

Answer 1

Mouth/Nose -> Trachea -> Bronchi -> Bronchioles -> Alveoli

Question 2

Characteristics and adaptations of alveoli

Answer 2

Function: To bring oxygen from air -> bloodstream and to remove CO2 and other waste products from bloodstream

• Many alveoli: increases S.A
• Thin wall decreases diff. distance
• Surrounded by many capillaries, ensures good blood flow which maintains steep conc. gradient
• Ventilation: continuus gas flow maintains conc. gradient

Question 3

Composition of inspired vs. Expired air

Answer 3

Inspired:
78% nitrogen, 21% oxygen, 0.04% CO2, lower water vapour

Expired: 78% nitrogen (no change) 16% oxygen (lower) 4% CO2 (higher) higher water vapour

higher water vapour is bc when we exhale moistre from alveoli evaporates