If I want to stay alive (which I do) I must
make sure I do not get too hot or too cold, or
that I do not loose or drink too much water,
loose or eat too much salt, and make sure my
blood sugar levels remain at an acceptable
level.
Syllabus 11.1
Homeostasis is the name for how I control all
these internal conditions. Not surprisingly, it
is controlled by hormones.
USE THE TEXT BOOK TO HELP ANSWER THESE QUESTIONS!!
WHEN HOT
WHEN COLD
•
•
________________ glands make
_______________ glands STOP
_____________. This uses body
making ____________.
HEAT as it _____________________
•
Surface blood vessels get
•
Surface blood vessels get
_________________ , less hot
__________________ and more
___________ reaches the skin
hot ___________ reaches the skin
surface & less __________ is
surface. More ___________ is lost
lost by RADIATION.
by RADIATION
If body
temperature
rises too high
or falls to low
enzymes in the
body fail to
function
properly. This
could lead to
death.
Blood temp
FALLS
BLOOD gets HOT
FOOD
EATEN
Brain
SWITCHES
ON
Cooling
NORMAL
body
NORMAL
body
temperature
BLOOD gets
COLD
temperature
Brain
SWITCHES
ON
Warming
BLOOD SUGAR
LEVELS ARE KEPT
HIGH IN THIS WAY
UNTIL NO STORED
GLYCOGEN IS LEFT..
BLOOD temp
RISES
INSULIN MADE BY
PANCREAS
CONVERTS EXTRA
SUGAR TO
GLYCOGEN FO
STORAGE IN LIVER
EVENTUALLY BLOOD SUGAR LEVEL WILL
FALL. THIS WIL HAPPEN MORE
QUICKLY WITH EXERCISE. THE
PANCREAS NOW PRODUCES GLUCAGON
TO CONVERT STORED GLYCOGEN BACK
TO GLUCOSE
WATER RISES
(after drinking)
WATER
PITUITARY GLAND
(BRAIN) releases LESS
ADH. KIDNEY allows more
WATER to enter URINE
NORMAL blood
water level
NORMAL blood
Water level, which may soon drop below
Normal if no more fluid is taken
PITUITARY GLAND
(BRAIN) releases MORE
ADH. KIDNEY allows LESS
WATER to enter URINE
WATER
RETAINED
WATER LOSS, DUE TO
RESPIRATION,
SWEAT ETC
Questions (use text book to help find answers (begin searching on page 20)
1. What is homeostasis and why is it important?
2. Name 4 internal conditions controlled by homeostasis.
3. Use page 20 to find out how we loose (ions) salt. Where do you think we get our
ions from?
4. what is the job of insulin?
5. what would happen to our blood sugar levels if we could not produce insulin?
6. some people are unable to produce enough insulin of their won and must inject it
into themselves daily. What illness are such people aid to have?
7. what is a negative feedback loop? Give an example of where one is found/