Gas Exchange Flashcards
State 2 functions of the respiratory system.
Pulmonary ventilation
Gas exchange
State 2 types of gas exchange.
What are they?
External respiration: at the lungs (o2 into blood, co2 into lungs)
Internal respiration: at the muscles (o2 into respiring cells, removal of waste products)
8 mechanics of breathing?
Larynx Trachea Bronchi Bronchioles Alveoli Ribs Diaphragm Intercostal muscles
How does the blood transport oxygen?
Bound to haemoglobin - 97% of o2
In plasma in the blood - 3% of o2
What does oxygen and haemoglobin form?
Oxyhaemoglobin
How is co2 transported in the blood?
In blood plasma - 8% of co2
Bound to haemoglobin in RBC’s - 20% of co2
In water (cytoplasm) as carbonic acid - 70% of co2
What does co2 and haemoglobin form?
Carbaminohaemoglobin
Why does co2 need to be removed?
To prevent fatigue
What is breathing frequency, tidal volume and minute ventilation?
Breathing frequency (BF) - breathes per minute Tidal volume (TV) - volume of air inspired or expired per breath Minute ventilation (VE) - TV x BF
2 functions of pulmonary diffusion?
Replenish blood with oxygen
Remove blood of co2
What is partial pressure?
The pressure exerted by an individual gas in a mixture of gasses.
How to gasses move?
What to what
High to low partial pressure.
What unit is partial pressure measure in?
mmHg
What is internal and external respiration?
Internal: gas exchange at the muscles
External: gas exchange at the lungs
What is the atmospheric pressure of co2 and o2?
Co2: 0.23 (low)
O2: 159 (high)
What is the pressure of o2 in the blood before and after the lungs?
Before: 40 (low)
After: 100 (high)
Why is there a high partial pressure of o2 in the alveoli?
It contains atmospheric air where the pressure of o2 is 159.
Po2 in the capillaries is 40.
159>40
What happens to external respiration during exercise?
The diffusion gradient of o2 steepens and therefore diffuses at a faster rate from a higher ppo2 in the alveoli to a lower ppo2 in the capillary blood.
The diffusion gradient of co2 steepens and therefore diffuses at a greater rate from a higher ppco2 in the capillary blood to a lower ppco2 in the alveoli.
What happens to internal respiration during exercise?
The diffusion gradient of o2 steepens and therefore diffuses at a faster rate from higher ppo2 in the capillary blood to lower ppo2 in the respiring muscle cells.
The diffusion gradient of co2 steepens and therefore diffuses at a higher rate from higher ppco2 in the respiring muscle cells to lower ppco2 in the capillary blood.
At rest, how much haemoglobin is saturated with o2; what does this mean?
75% saturated
25% of o2 is dissociated from the haemoglobin into the muscles.
During exercise what % of haemoglobin is saturated with o2; what does this mean?
25% saturated with o2
75% of o2 is dissociated from the haemoglobin into the muscle cells for aerobic respiration.
4 reasons that o2 dissociates more during exercise than at rest?
Decreased blood pH
Increased co2
Increased lactic acid
Increased temperature
What is the Bohr shift on a graph?
The oxyhemoglobin dissociation curve shifts to the right as more oxygen is dissociated.
