respiratory system Flashcards
describe what happens during inhalation at rest
-external intercostals contract, pulling ribs up and out
-diaphragm contracts and flattens
-thoracic capacity volume increases
-lung air pressure fills below atmospheric air pressure
-air is inhaled
describe what happens during inhalation at exercise
-external intercostals contract more than at rest, pulling ribs up
-recruited the muscles: sternocleidomastoid, scalene and pectoralis major
-diaphragm contracts with more force than at rest
-thoracic capacity volume increases more than at rest
-lung air pressure decreases below atmospheric air pressure more than at rest
-more air is inhaled than at rest
what happens during exhalation at exercise
-external intercostals relax
-internal intercostals and rectus abdominus contract
-diaphragmrelaxes back to dome
-thoracic capacity volume decreases faster than at rest
-lung airpressure increases faster than at rest
-air is forced out faster than at rest
what happens during gaseous exchange at rest (external)
a diffusion gradient is created by there being a high PPO2 in alveoli and low PPO2 in capillaries. Also a high PPCO2 in capillaries and low PPCO2 in alveoli.
what happens during gaseous exchange at rest (internal)
a diffusion gradient is created by there being a high PPO2 in capillaries surrounding muscles and low PPO2 in muscles. Also a high PPCO2 in muscles and low PPCO2 in capillaries surrounding muscles
what happens during gaseous exchange at exercise (external)
a larger diffusion gradient is created by there being a higher PPO2 in alveoli and lower PPO2 in capillaries. Also a higher PPCO2 in capillaries and lower PPCO2 in alveoli.
what happens during gaseous exchange at exercise (internal)
a larger diffusion gradient is created by there being a higher PPO2 in capillaries surrounding muscles and lower PPO2 in muscles. Also a higher PPCO2 in muscles and lower PPCO2 in capillaries surrounding muscles
What is partial pressure
The pressure of a gas tells us how much oxygen is available
Higher O2 in blood means higher partial pressure
What does the disassociation curve describe
How much of the O2 is going to be saturated with haemoglobin in the blood
What happens when the disassociation graph plateaus
Increased partial pressure means a smaller increase in saturation
What is the Bohr shift
haemoglobin has a lower affinity for oxygen at working muscles, giving up oxygen more easily
What determines the direction which the curve shifts on a disassociation graph
An increase in partial pressure of carbon dioxide will shift the curve to the right, whereas a decrease in partial pressure of carbon dioxide shifts the curve to the left.
What affect does the Bohr shift have on the blood
Increases CO2 levels And Decreases pH which causes a reduced affinity of haemoglobin for O2
what is oxyhaemohlobin
haemoglobin carrying oxygen in blood
what is tidal volume
the amount of air breathed in with each normal breath
