Flashcards in Exchange Surface Deck (9):
Why do multicellular organisms need to gave specialised exchange surface?
Meet cellular needs as have high metabolic demands and SA:V gets smaller as organism gets bigger
What makes a good exchange surface?
Short diffusion pathway
Good blood supply
Why can single celled organisms survive without specialised exchange system?
Have larger SA : V ratio so have short diffusion pathway directly to cells
Low metabollic activity
How to work SA:V?
How is naval cavity adapted?
Large SA and good blood supply = warm up blood
Hairy lining which secrete mucus to trap dust
Moist surface which increase humidity of air which reduce water loss
Describe structure of trachea?
Incomplete rings of cartilage
Ciliated epithelium - cilia beat to move mucus
Goblet cells - produce mucus and secrete on to epithelium
Which has incomplete rings of cartilage Bronchus or bronchioles?
How do bronchioles control amount of air that reach lungs?
Have smooth muscle which can contract and dilate