Exchange of materials - Active transport
OSMOSIS and DIFFUSION are the movement of substances from a higher concentration to a lower concentration.
ACTIVE TRANSPORT - takes substances AGAINST a concentration gradient and involves energy
Exchange of gases in the lungs
Lungs exchange OXYGEN (needed for AEROBIC respiration) and CARBON DIOXIDE (waste respiration product). The lungs are protected by the rib cage and are separated from the digestive organs in the lower part of the body by the diaphram.
The lungs are adapted to make gas exchange more efficient by:
A LARGE SURFACE AREA MOIST
RICH BLOOD SUPPLY - maintain a high concentration gradient THIN
Allows diffusion to take place quickly
Oxyegn diffuses into the capilaries surrounding the alveoli and carbon dioxide diffuses back out into the lungs