11. Fig. 40-4
.5 cm
Nutrients
Digestive
system
ining of small intestine
Mouth
Food
External environment
Animal
body
CO2 O2
Circulatory
system
Heart
Respiratory
system
Cells
Interstitial
fluid
Excretory
system
Anus
Unabsorbed
matter (feces)
Metabolic waste products
(nitrogenous waste)
Kidney tubules
10 µm
50µm
Lung tissue
81. Fig. 40-16
Sweat glands secrete
sweat, which evaporates,
cooling the body.
Thermostat in hypothalamus
activates cooling mechanisms.
Blood vessels
in skin dilate:
capillaries fill;
heat radiates
from skin.
Increased body
temperature
Decreased body
temperature
Thermostat in
hypothalamus
activates warming
mechanisms.
Blood vessels in skin
constrict, reducing
heat loss.
Skeletal muscles contract;
shivering generates heat.
Body temperature
increases; thermostat
shuts off warming
mechanisms.
Homeostasis:
Internal temperature
of 36–38°C
Body temperature
decreases;
thermostat
shuts off cooling
mechanisms.
84. Fig. 40-17
Organic molecules
in foodExternal
environment
Animal
body Digestion and
absorption
Nutrient molecules
in body cells
Carbon
skeletons
Cellular
respiration
ATP
Heat
Energy lost
in feces
Energy lost in
nitrogenous
waste
Heat
Biosynthesis
Heat
Heat
Cellular
work
90. Fig. 40-19
Elephant
Horse
Human
Sheep
DogCat
Rat
Ground squirrel
Mouse
Harvest mouse
Shrew
Body mass (kg) (log scale)BMR(LO2/hr)(Iogscale)
10–3 10–2
10–2
10–1
10–1
10
10
1
1 102
102
103
103
(a) Relationship of BMR to body size
Shrew
Mouse
Harvest mouse
Sheep
Rat Cat
Dog
Human
Horse
Elephant
BMR(LO2/hr)(perkg)
Ground squirrel
Body mass (kg) (log scale)
10–3
10–2
10–1
1 10 102
103
0
1
2
3
4
5
6
8
7
(b) Relationship of BMR per kilogram of body mass to body size
91. Fig. 40-19a
Shrew
Harvest mouse
Mouse
Ground squirrel
Rat
Cat Dog
Sheep
Human
Horse
Elephant
Body mass (kg) (log scale)
BMR(LO2/hr)(logscale)
(a) Relationship of BMR to body size
10–3
10–2
10–2
10–1
10–1
1
1
10 102
103
10
102
103
101. Fig. 40-21
Additional metabolism that would be
necessary to stay active in winterActual
metabolism
Arousals
Body
temperature
Outside
temperature
Burrow
temperature
Metabolicrate
(kcalperday)Temperature(°C)
June August October December February April
–15
–10
–5
0
5
15
10
25
20
35
30
0
100
200