Gas Exchange Flashcards
Where does gas exchange occur?
in the aveoli
what is fick’s law?
rate of diffusion
__________ also helps ______ the concentration gradient
- Ventilation
* maintain
What 2 boundary’s does gas exchange go through?
The capillary wall and the alveoli wall which are both single felled stuctures.
How is the alveoli adapted for Gas exchange?
- diameter is 200 - 300 micrometers
- made up of flatten epithelium cells, collagen and elastic fibres
- elastic fibres recoil which helps move air out the way
- 300 - 500 million alveoli per lung. Combined SA of 75m2
What the demand for gas exchange?
- Mammals have a small surface area to volume ratio
* Mammals have a high metabolic rate therefore more oxygen is needed
Rate of diffusion is proportional to ______
Difference in concentration
Rate of diffusion is diversely proportional to __________
Thickness of gas exchange
Rate of diffusion is directly proportional to ______
Surface area
Describe how the structure of mammalian lungs are adapted for rapid gas exchange.
Rate of diffusion is directly proportional to surface area, mammalian lungs are adapted to this by having lots of aveoli therefore having a large surface area.
Rate of diffusion is proportional to difference in concentration, mammalian lungs are adapted to this by having loads of capillaries therefore a good blood supply.
Rate of diffusion is inversely proportional to thickness of gas exchange surface, mammalian lungs are adapted to this by having a one cell thick gas exchange surface called the endothelium.
How many capillaries contain the concentration gradient?
280 million
Using Fick’s law, what are the properties that gas exchange surfaces in living organisms?
- lots of alveoli therefore large surface area
- Endothelium is one cell thick - short diffusion distance
- Lots of capillaries therefore good blood supply
