An introduction to homeostatic biological systems. Thermoregulation and blood glucose levels are used as examples.

1. Sir Charles Blagden
What are effects of
extreme heat on the
body?
How do we resist heat?
See the video

2. Thermoregulation

3. Thermoregulation
Too hot

4. Thermoregulation
Too hot
cc licensed flickr photo by Finizio: http://flickr.com/photos/finizio/492955038/

5. Thermoregulation
Too hot
Too cool
cc licensed flickr photo by Finizio: http://flickr.com/photos/finizio/492955038/

6. Thermoregulation
Too hot
cc licensed flickr photo by MaryLane: http://flickr.com/photos/marylane/520905761/
Too cool
cc licensed flickr photo by Finizio: http://flickr.com/photos/finizio/492955038/

7. Homeostasis of house temperature
cc licensed flickr photo by rustybrick: http://flickr.com/photos/rustybrick/2151548025/
cc licensed flickr photo by slworking2: http://flickr.com/photos/slworking/394991055

8. Homeostasis of house temperature
cc licensed flickr photo by rustybrick: http://flickr.com/photos/rustybrick/2151548025/
cc licensed flickr photo by slworking2: http://flickr.com/photos/slworking/394991055

9. Homeostasis of house temperature
Too cold
cc licensed flickr photo by rustybrick: http://flickr.com/photos/rustybrick/2151548025/
cc licensed flickr photo by slworking2: http://flickr.com/photos/slworking/394991055

10. Homeostasis of house temperature
Too cold
cc licensed flickr photo by rustybrick: http://flickr.com/photos/rustybrick/2151548025/
cc licensed flickr photo by slworking2: http://flickr.com/photos/slworking/394991055
cc licensed flickr photo by Xystance: http://flickr.com/photos/xystance/4278997785/

11. Homeostasis of house temperature
Too cold
Too hot
cc licensed flickr photo by rustybrick: http://flickr.com/photos/rustybrick/2151548025/
cc licensed flickr photo by slworking2: http://flickr.com/photos/slworking/394991055
cc licensed flickr photo by Xystance: http://flickr.com/photos/xystance/4278997785/

12. Homeostasis of house temperature
Too cold
Too hot
cc licensed flickr photo by rustybrick: http://flickr.com/photos/rustybrick/2151548025/
cc licensed flickr photo by slworking2: http://flickr.com/photos/slworking/394991055
cc licensed flickr photo by Xystance: http://flickr.com/photos/xystance/4278997785/

13. Homeostasis of house temperature
Too cold
Too hot
cc licensed flickr photo by rustybrick: http://flickr.com/photos/rustybrick/2151548025/
return temp to
normal range
cc licensed flickr photo by slworking2: http://flickr.com/photos/slworking/394991055
cc licensed flickr photo by Xystance: http://flickr.com/photos/xystance/4278997785/

14. Thermoregulation is an example of homeostasis
def’n - the property of a system that regulates its internal
environment and tends to maintain a stable, constant condition
despite changing external conditions

15. Thermoregulation is an example of homeostasis
def’n - the property of a system that regulates its internal
environment and tends to maintain a stable, constant condition
despite changing external conditions
All living things exhibit homeostasis

16. Homeostatic systems require:
a receptor - monitors and responds to changes
in the system
a control center - sets the range for the
condition
an effector - produce an action which moves
the system back into the desired range

17. Thermoregulation
cc licensed flickr photo by labguest: http://flickr.com/photos/labguest/3467278568/

18. Thermoregulation

19. Thermoregulation
When too hot:
• sweat
• vasodilation (blood vessels open up so warm blood
can get to surface of skin)

20. Thermoregulation
When too hot:
• sweat
• vasodilation (blood vessels open up so warm blood
can get to surface of skin)
When too cold:
• shiver
• goose bumps
• vasoconstriction (blood vessels close up so heat isn’t
lost through the skin)
• adrenal and thyroid glands - increase overall
metabolism

21. Blood sugar regulation
cc licensed flickr photo by EUSKALANATO:
http://flickr.com/photos/
17657816@N05/1971827663/
Receptor (hypothalmus) responds
to high blood sugar level
Control center (hypothalmus)
Sends
signal to
the pancreas releases insulin
cc licensed flickr photo by djneight: http://flickr.com/photos/thedjneight/4119439462/

22. Effects of insulin
• cells absorb more glucose (blood sugar)
• liver stores glucose as glycogen
• fat storage
Lower blood sugar level