The Mammalian Gas Exchange System Flashcards
What is the point of the nasal cavity having a moist surfaces
The moisture in the nose helps to heat and humidify the air, increasing the amount of water vapour the air entering the lungs contains
How are the gas exchange systems fit their purpose
moist surfaces as diffusion takes place with the gases in solution
Permeable surfaces that will allow free passage of the respirorty gases
Thin layers to minimise the diffusion distance from one side to the other
Where does gas exchange occur
alevoli
What is the strucutre of the alveoli
Made of a single layer of flattened epitheilail cells
capilaries that run next to the alveoli are one cell thick
between this layer is a elastic connective tissue holding everything together
What is the point of the elastic tissue
helps to force air out of the lungs which are streched when you breath in
What is the role of the lung surfacntant
the alevoli have a natural tendency to collapse this is stopped by the phosphlipid LS that coats the alevoil and makes breathing easier
How does gaseous exchange occur
Oxygen diffuses from the alveoli to the blood in the capillaries,
and Carbon Dioxide diffuses from the capillaries to the alveoli
What does the respiratory system produce to stop infection and damage to the lungs
Mucus
What does mucus do
traps tiny particles and orgnaisms
Why is the mucus runny
easily moved up the airways by cilia that sweep upwards to back of your throat
Why is breathing important in maintaining concentration gradients in the alveoli air
Maintaining a steep gradient will cause oxygen to diffuse into the blood quicker because there will be less oxygen in the blood than there is in the lungs.
How is the nasal cavity suited for its role
Large surface area
good blood supply
lining secretes mucus and is covered in hairs
moist surfaces
What are the adaptions of the alveoli
large surface area
Steep concentration gradient
short diffusion distance
Explain how the double C system enables mammals to carry out effective gas exchange
One side of the heart transports blood to the lungs the other side of the body
DCS ensures seperation of OB and DOB
The DCS maintains a concentration gradeint
What are the adaptations of the alevoli
One cell thick resulting in short diffusion distance
Blood flow maintains concentration gradient
Surfactnat prevents collapse of alveoli
