gaseous exchange

Question 1

at rest - expiration

Answer 1

• low partial pressure of co2 in alveoli
• high partial pressure of co2 in capillary blood
• steep concentration gradient between alveoli + capillary
• co2 diffuses from the blood into the alveoli
• high pp of o2 in alveoli
• low pp of o2 in capillary blood
• steep concentration gradient between alveoli + capillary
• o2 diffuses from alveoli into blood

Question 2

at rest - inspiration

Answer 2

• high pp of o2 in blood
• low pp of o2 in muscle cell
• steep concentration gradient between blood and muscle cell
• o2 diffuses from blood into muscle cell
• high pp of co2 in muscle cell
• low pp of co2 in blood
• steep concentration between blood and muscle cell
• co2 diffuses from the muscle cell into blood

Question 3

during exercise - expiration

Answer 3

• high pp of o2 in alveoli = same as rest
• lower pp of o2 in capillary returning to the alveoli than at rest
• steeper conc. gradient between alveoli + capillary than at rest
• more o2 diffuses from alveoli into blood
• low pp of co2 in alveoli = same as rest
• higher pp of co2 in blood returning to alveoli than at rest
• steeper conc. gradient between alveoli + capillary than at rest
• more co2 diffuses from blood into alveoli

Question 4

during exercise - inspiration

Answer 4

• high pp of o2 in blood
• lower pp of o2 in muscle cell than at rest
• steeper conc. gradient between blood and muscle cell than at rest
• more o2 diffuses from blood into muscle cell
• low pp of co2 in blood
• higher pp of co2 in muscle cell than at rest
• steeper conc. gradient between blood capillary and muscle than at rest
• more co2 diffuses from blood into muscle cell