Exchange surfaces and breathing Flashcards
there are three main factors that affect the exchange system. what are they
Size of the animal
the SA:V ratio
the metabolic rate
How does a body provide effective exhange
This is done by a large surface area for the process to take place. A good supply of blood , short diffusion distance and fast movement of air. and strong gradient to diffuse across.
Name two types of epithelium tissue in the lungs and airwways
These are the squamus and the cilia epithelium tissue
How are the alveoli effectively formed to allow gaseous exchange
large surface area, coated in capillaries, only lined with single celled tissue for fast diffusion and they have a very good blood supply.
Name the air sacs and why are there so many of them in the lungs
The air sacs are the alveoli and there are so many so that there is a large surface area for the gaseous exchange to take place.
Explain the uses of the elastic fibres during ventilation
They line the lungs as they have the characteristics of being able to stretch during inhalation and are able to recoil and compress in exhalation.
Explain how refreshing the air in the lungs is key to maintaining a diffusion gradient
When new air flows in there is a higher O2 conc in the new air than in the capillaries and there is a lower CO2 conc in the air in comparison to the capillaries and therefore both diffusion gradient are maintained at a steep level.
Describe and explain one other way in which a steep diffusion gradient is maintained in the lungs
This is the fresh and continuous blood supply of deoxygenated blood that allows for the diffusion of High conc in the alveoli to the low conc in the capillaries.
Using the mammalian gaseous exchange system as an example explain how the different cells and tissues enable effective exchange of gases 5 marks
For this 5 marker you must include 5 main points and then describe each of them. These 5 points must only be about the tissue and cells in the exchange system all others count to nothing.
The exchange system has two main cells that help its effectiveness with the use of squamous epithelium for a short diffusion distance between alveoli and capillaries, and there is the thin epithelium that is as surfactant to reduce the surface tension on the alveoli to prevent collapse. Some of the tissue used is the elastic fibres in lining the lungs so that they can stretch and recoil during both stages of breathing. There is also the cartilage that holds the airway open.
What is the name of the test used to measure lung capacity and how is it carried out.
The test is called a spirometer and is carried out by a person breathing into the mouthpiece, the air then travels to the soda lime which absorbs all the CO2 in the air and then the air chamber is raised which is connected to a pen and paper drawing a line for the capacity measured per breath.
Outline the mechanism of inspiration using technical terms
The diaphragm / intercostal muscles contract
The diaphragm moved down and then the ribs move up and out to increase overall capacity. Also the atmospheric pressure int he lungs decrease to increase are flow
Outline the mechanism of expiration
Opposite of inhalation
What chemical is used to absorb the carbon dioxide in the spirometer
Soda lime
Why would a person wear a nose clip when measuring vital capacity?
This is so no air is being taken in by the nose or any air isn’t being exerted by the nose only through the mouth into the mouthpiece
State two precautions that should be taken when using a spectrometer to measure vial capacity.
The mouthpiece should be cleaned and the person should be showing no signs of having asthma as this can lead to an attack when completely exerting the air in the lungs. Other marks were given for use fresh oxygen supply and ensure that the correct equipment was being used and that it was all working properly.
