Lesson Objectives

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Lesson Objectives

• Students will understand the importance of
  homeostasis
• Students will understand the two types
  homeostatic of organisms
• Students will understand the two main ways
  organisms respond to stimuli
• Students will be introduced to the important
  factors of homeostasis in humans

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Homeostasis

• The ability of an organism to adjust its internal
  intracellular environment to deal with the outer
  environment for survival.

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Organisms must live with-in certain parameters to
survive optimally!
That said, there are 2 types of organisms in this
world.

• The CONFORMERS of the world- Say Tell me how
  its going to be environment and Ill do what
  you say.

• The REGULATORS of the world say The heck with
  what the environmental factors are, Im doing
  it my way!!

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Regulators

• Most regulators are usually endothermic animals,
  mammals and birds. They maintain a relatively
  constant body temperature.

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CONFORMERS

• Conformers are mostly ectothermic animals. They
  consist of most all organisms other than mammals
  and birds. Their body temperatures are able to
  fluctuate quite a bit.

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Homeostatic systems have 3 parts 1- Receptor-
Something that determines what the environment is
like. Monitors changes in the outer environment.
Think of a thermometer or water sensor in a
greenhouse. Tells us how hot or cold our outer
conditions are. 2-Control center- Part of the
system that determines when something needs to be
done and decides what will be done to deal with
the change in the external environment. The
thermostat or greenhouse monitoring
system. Determines how hot or dry things are
and then determines whether to turn on the heater
or the air conditioner and determines when and
how much to water. 3- Effector- The reaction
of the organism to the outer environment, to
return the organism back to optimal working
conditions. This is the heater, the a/c unit
or the sprinkler. Whatever is used to return the
system to optimal levels.
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Feedback is the systems response to a stimulus

• Positive Feedback

• Negative Feedback

• Feedback that accelerates the normal output of a
  system
• Positive feedback mechanisms are designed to push
  levels out of normal ranges.
• Examples- Accumulation of blood platelets to
  promote blood clotting.

• feedback reducing the output or activity of any
  organ or system back to its normal range of
  functioning.
• Blood vessels sense resistance of blood flow
  against the walls when blood pressure increases.
  The blood vessels act as the receptors and they
  relay this message to the brain. The brain then
  sends a message to the heart and blood vessels,
  both of which are the effectors. The heart rate
  would decrease as the blood vessels increase in
  diameter (or vasodilation). Resulting in less
  pressure.

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What part of your body does homeostasis
effect?...Pretty much all of it!!

• Quick question, what would happen if we couldnt
  sweat?

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In humans there are 6 main bodily levels that
need to be controlled.

• CO2 and Urea need to be disposed of, and Ion
  content, water content, sugar content (of the
  blood), as well as temperature all need to be
  kept at a constant level.
• CO2 Created and removed by gas exchange in the
  lungs.
• Urea- Poisonous fluid created as a by product of
  breaking down amino acids.
• Ion content- minerals taken in with food and
  absorbed in the bloodstream. Removed by the
  kidneys and sweating.
• Water content- levels in the blood are monitored
  by the hypothalamus. The kidneys are responsible
  for water levels.
• Sugar content- The liver and pancreas work to
  control sugar levels in the blood. The pancreas
  produces insulin, which makes the liver turn
  glucose into glycogen.
• Temperature- Blood temperature is monitored by
  the hypothalamus, which then sends nerve impulses
  to the skin.

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Almost all mammals can regulate their body
temperatures to conform to a certain temperature
parameter.
Why not me!!!
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Homeostasis In conclusion

• Organisms ability to keep constant intracellular
  conditions.
• 2 Types of organisms REGULATORS and CONFORMERS
• 3 Parts of a homeostatic system
• Receptor
• Control Center
• Effector
• 2 Types of responses
• Negative feedback
• Positive feedback
• There are many different types of organisms and
  all organisms rely on homeostasis for optimal
  growth and production.