Transcript Compare the roles of respiratory, circulatory and excretory systems

Compare the roles of respiratory, circulatory and excretory
systems
Respiratory System
The respiratory system enables gaseous
exchange to occur between an organism and its
external environment. Organisms take in oxygen
which is essential to keep alive and remove
carbon dioxide as it can becomes toxic if
present in large quantities.
The organs responsible differ between animals
as mammals have lungs and fish have gills.
Circulatory (transport) System
A transport system ensures that all cells in an
organism are supplied with necessary nutrients
and gases as well as removing waste.
The circulatory system transports gases eg
oxygen and carbon dioxide, nutrients, waste
products, hormones and antibodies. It is
responsible for maintaining a constant internal
environment ie pH and osmotic pressure. The
circulatory system also removes any toxins or
pathogens and is responsible for the
distribution of heat.
Excretory System
The excretory system is responsible for removing
metabolic wastes from the blood and to expel
them from the organism.
Two main waste products are:
 Nitrogenous wastes – excreted as part of urine
 Carbon dioxide – expelled from the lungs
Excretory system is closely linked to water balance in
an organism. The more toxic the waste, the greater
amount of water is needed to dilute it for
excretion.
Some organisms also use the excretory system to
eliminate excess salts, regulate pH of body fluids
and blood pressure.