Zusammenfassung der Ressource
Excretory System
- What?
- Lungs- CO2
- Kidney- Urea
- Skin- urea
- Liver- bile salts
- Why?
- To expel wastes that have been made by
cells as a by-product of metabolism. If
waste accumulates then it becomes toxic
- How?
- Nitrogenous waste, water and
other substances combine to
make urine
- The greater the toxicity of the waste, the
more water required to dilute it for
excretion
- Where
- Lungs- removes CO2 from blood
- Kidney- removes urea from blood
- Skin- removes quantities of
urea from blood
- Liver- removes pigment
(haemoglobin) from warn out red
blood cells
- http://www.youtube.com/watch?v=TZMJeZL-BVg