SPLATS about gaseous exchange
For an explanation, see
the main splats page
Oxygen is needed inside most organisms' cells to extract energy from most forms of food, although oxygen gas is harmful and poisonous to anaerobic organisms.
Plants do not need circulatory systems to carry oxygen because they have air spaces between their cells, and gases are able to diffuse through those gaps.
Animals need oxygen. Animals use all of lungs on land, gills in water, and diffusion systems in small animals to acquire oxygen from their environment.
A fish can get oxygen from water through its gills, which work to provide a large surface area for contact with the water to allow oxygen to diffuse in.
Small animals absorb oxygen by diffusion through the skin, while larger animals use breathing systems to carry oxygen in: lungs and gills and in insects, tubes.
Our lungs fill with air when the diaphragm falls, or the ribs move up and out: as the space expands, air can move in, as it contracts, air is forced out again.
This file is http://members.ozemail.com.au/~macinnis/scifun/, first created on February 17, 2009. Last
revision (well I get lazy and forget sometimes!) was on February 17, 2009.
©The author of this work is Peter Macinnis, who asserts his sole right to the product as it is packaged here, recognising that many of the ideas are common. You are free to use this as a model to do your own version. Copies of this whole file or site may be made and stored or printed for personal or educational use. You can contact me at firstname.lastname@example.org, but
if you add my first name to the front of that email address -- this is a low-tech way of making it harder to harvest the e-mail address I actually read.
This site had 219,000 hits on the index page from 1999 to January 2007 and an unknown number on other pages. In January 2007, a combined counter was placed on all of the pages, counting page hits which now total