Gas Exchange Flashcards
What is the air pressure at sea level?
101 KPa
Why is there a difference in partial pressure within the body compared to outside?
Metabolic processes
What happens to the partial pressure at higher altitude?
It becomes lower
What carries less oxygen, warm or cold water?
Warm water
Give the four definitions for different levels of oxygen:
Anoxia= no oxygen Hypoxia= low levels Normoxia= normal Hyperopia= higher levels of oxygen
Why is diffusion not a problem for small animals?
Has to be less than 1mm in order to just rely on diffusion, otherwise it will be too slow to get oxygen to the cells
How is diffusion augmented?
Diffusion enhancement
Bulk transport
Give some ways of enhancing diffusion:
High permeability in respiratory organs A low diffusion distance Large SA Vascularisation or bathed in coelomic fluids Partial pressure difference
What are the two main forms of bulk transport?
Ventilation and circulation
What are the two forms of ventilation/breathing?
Tidal: breathing in and out
Flow through: e.g gills
How much quicker is diffusion in air compared to water?
10,000x quicker
Name an aquatic animal that uses tidal rather than flow through ventilation. Why do they do this?
Sea cucumbers/Holothurians
Because they have a slow metabolic rate and are able to extract sufficient oxygen
What ventilation does an octopus/squid use? Briefly describe it
One way ventilation
Water goes in through slit with gills and out of the siphon
Pressure is greater in upper mantle than lower mantle
What ventilation does a fish use to obtain oxygen?
Countercurrent system
Blood flows in the opposite direction to the water passing over the gills
How does a fish cause the pressure to build up so the water moves out of the gills?
Closes its mouth
