Gas Exchange Flashcards
What does the term SA:V mean
-a measure of the overall surface area of an organism compared to its size
What is the SA:V of amoeba and why is this important for it s gas exchange
-they have a large SA:V (as they are small)
-this means that they can rely on simple diffusion to get O2 and CO2 in and out for the cell (short diffusion pathways)
Fill in the blank:
As the size of an object INCREASES, the surface area to volume ratio _________
-DECREASES
What can changes to body shape allow organisms to do
-to increase their surface area to volume ration and so improve exchange of materials
What 4 features make up an efficient exchange surface
1) Large surface area
2) Thin layer
3) Good blood supply
4) Moist surface
Why is a large surface area helpful for an efficient exchange surface
-increases the space available for diffusion (e.g alveoli)
Why is a think layer helpful for an efficient exchange surface
-as it reduces the distance substances must diffuse (e.g on cell think walls in capillaries)
Why is a good blood supply helpful for an efficient exchange surface
-helps maintain a steep concentration gradient by quickly transporting substances away
Why is a moist surface helpful for an efficient exchange surface
-helps dissolve gases or nutrients for easier diffusion (e.g mucus in the alveoli)
What does the mammalian gas exchange system contain
In the left and right lung:
-trachea (main windpipe)
-bronchi (left and right bronchus)
-bronchioles
-alveoli
-diaphragm
What other structures (muscles & cells) are found in the mammalian gas exchange system
-C cartilage
-ciliated epithelium
-goblet cells
-smooth muscle
-elastic fibres in the trachea
-squamous epithelium
Where is the C shaped cartilage found and what is its function
-found around the trachea and bronchi
-its function is to hold those structure open and prevent them from collapsing
Where is the ciliated epithelium found and what is its function
-found in the trachea and bronchi
-its functions is to move substances along it surface using its tiny hair like structures (cilia)
-cilia help move mucus towards the throat where it can be swallowed or coughed out
Where is the goblet cells found and what is its function
-found in the trachea and bronchi
-function: to produce and secrete mucus which traps microbes
Where is the found and what is its function
