Homeostasis
• The body controls internal conditions by 1……………..
• The body 2………….. of the body is kept steady at 37
oC The skin is involved in this process by
3…………….. and 4……………...
• The level of glucose in the blood is kept steady by the
5…………….. and 6……………..
• Blood water level and 7….. are controlled by the
8…………….. Carbon dioxide level in the blood is
controlled by the 9……………...
Ch7
Homeostasis
• The body controls internal conditions by homeostasis
• The body temperature of the body is kept steady at
37 oC The skin is involved in this process by sweating
and vasodilation
• The level of glucose in the blood is kept steady by the
pancreas and liver
• Blood water level and pH are controlled by the
kidneys
• Carbon dioxide level in the blood is controlled by the
lungs.
Ch7
Control of blood sugar level
food
glucose
rises
glucose
insulin
glycogen
normal blood
glucose level
normal blood
glucose level
glycogen
glucose
falls
glucose
falls
glucagon
glucose
glucose
rises
exercise
Ch7
Control of body temperature
• The body temperature of humans is 1……… oC.
Body too warm?
• Vasodilation allows more blood through the skin so
more heat is lost by 2………….. and
3…………………
• Sweat glands release sweat to lose heat through 4
…………………. .
Body too cold?
• 5…………………………….. , less heat loss.
• Sweat glands stop.
• Shivering, 6………………… contract to generate
heat.
Ch7
Control of body temperature
• The body temperature of humans is 37 oC.
Body too warm?
• Vasodilation allows more blood through the skin so
more heat is lost by radiation and convection.
• Sweat glands release sweat to lose heat through
evaporation.
Body too cold?
• Vasoconstriction: less heat loss.
• Sweat glands stop.
• Shivering: muscles contract to generate heat.
Ch7
Vasoconstriction
Vasodilation
1
dilate
2
more blood flows in capillaries
3
radiation
4
evaporation
5
constrict
6
less blood flows in capillaries
Ch7
Excretion
•
•
•
•
Excretion is the removal of 1………. from our cells.
Lungs remove carbon dioxide from the 2………….
The sweat glands release 3………….. in the sweat.
The liver:
• excretes waste in 4……………
• makes urea from spare 5…………. …………….
• The kidneys remove 6……………., spare water and
spare salt 7…………….. from the blood.
Ch7
Excretion
•
•
•
•
Excretion is the removal of waste from our cells.
Lungs remove carbon dioxide from the blood.
The sweat glands release urea in the sweat.
The liver:
• excretes waste in bile
• makes urea from excess amino acids.
• The kidneys remove urea, excess water and spare
salt ions from the blood.
Ch7
The kidney
1.
2.
3.
4.
5.
urea
Blood containing………and
oxygen.
less
Blood containing ………
urea and less
oxygen.
Urine trickles to the bladder. Urine
contains urea, excess water and
ions
excess ……….
Small molecules like water, ions, urea
glucose enter the nephron by
and ……….…
ultrafiltration
………………….
Glucose water and ions re-enter blood
by …………………….……against
the
selective reabsorption
…………………..
concentration gradient which
involves active transport.
1
4
5
2
3
Ch7
The kidney
tubule
•
•
•
•
•
name
a ………………
b ………………
c ………….……
d ………………
: function
: …………….
: …………….
: …………….
: …………….
Ch7
The kidney
tubule
•
•
•
•
•
name
: function
a glomerulus
: ultrafiltration
b capsule
: receives filtered blood
c 1st coiled tube : selective reabsorption
d collecting duct : target for ADH
Ch7
Control of blood water content
water in the blood
not enough ………….
ADH
pituitary gland releases ……………
reabsorbs
kidney ………………….
more water
from the urine
makes a small volume of
………………………
urine
concentrated
Ch7
Control of blood water content
water in the blood
too much ………….
pituitary gland stops releasing ADH
……
reabsorbs
kidney ………………….
less water
from the urine
you make a large volume of
…………
dilute urine
Ch7
Diabetes
1 control • Diabetics cannot 1………….. their blood
glucose.They do not make the hormone 2………
2 insulin
• Glucose can often be found in their 3……….
3 urine • The condition can be controlled by:
carefully balanced diet
4 insulin
………. injections.
5 rises
6 drops
• Blood glucose 5………………..if a diabetic eats
too much sugar or does not get enough insulin.
• Blood sugar 6…………….. if a diabetic eats too
little sugar or takes too much insulin.
Ch7
Genetically engineered insulin
Diabetes used to be treated with insulin extracted
from the pancreas of ……….. or cows after they
had been slaughtered for meat.
Now insulin is made from genetically ………….
bacteria. It is called humulin.
This humulin is better because:
• it is the same as …………. insulin
• it has less side ……………
• it is more acceptable to ……………..
• it is more acceptable to some ………….
Ch7