HOMEOSTASIS & EXCRETION
Understand that homeostasis is the maintenance of
a constant internal environment.
LEARNING
OBJECTIVES
Understand that control of body water content and
body temperature are examples of homeostasis.
To know the excretory products of the lungs, kidneys
and skin.
To understand the origin of CO2 and O2 as a waste
product from leaf metabolism.
Role of skin in thermoregulation.
HOMEOSTASIS
URINE
• Urine is a clear, transparent fluid
that normally has an amber color.
• Chemically, urine is mainly a
watery solution of salt and
substances called urea and uric
acid.
• Normally, it contains about 960
parts water to 40 parts solid
matter.
CONTROL OF
BODY
TEMPERATURE
WARM
BLOODED
COLD BLOODED
CONTROL OF BODY
TEMPERATURE
WARM BLOODED
MAINTAINS A CONSTANT
INTERNAL BODY
TEMPERATURE
(HUMAN)
COLD BLOODED
BODY TEMERATURE
CHANGES WITH THE CHANGE
IN THE SURROUNDING
TEMPERATURE
(LIZARD)
THERMOREGULATORY CENTRE
THERMOREGULATORY CENTRE
HUMAN SKIN