Transcript Chapter 40

Chapter 40:
Basic Principles of
Animal Form and
Function
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 40.1 A sphinx moth feeding on orchid nectar
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Figure 40.2 Evolutionary convergence in fast swimmers
(a) Tuna
(b) Shark
(c) Penguin
(d) Dolphin
(e) Seal
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Figure 40.3 Contact with the environment
Mouth
Diffusion
Gastrovascular
cavity
Diffusion
Diffusion
(a) Single cell
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(b) Two cell layers
Figure 40.4 Internal exchange surfaces of complex animals
External environment
Food
CO2
O2
Mouth
Respiratory
system
0.5 cm
Cells
Heart
Nutrients
Circulatory
system
50 µm
Animal
body
A microscopic view of the lung reveals
that it is much more spongelike than
balloonlike. This construction provides
an expansive wet surface for gas
exchange with the environment (SEM).
10 µm
Interstitial
fluid
Digestive
system
Excretory
system
The lining of the small intestine, a digestive organ, is elaborated with fingerlike
projections that expand the surface area
for nutrient absorption (cross-section, SEM).
Anus
Unabsorbed
matter (feces)
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Metabolic waste
products (urine)
Inside a kidney is a mass of microscopic
tubules that exhange chemicals with
blood flowing through a web of tiny
vessels called capillaries (SEM).
Table 40.1 Organ Systems: Their Main Components
and Functions in Mammals
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Figure 40.6 Tissue layers of the stomach, a digestive organ
Lumen of
stomach
Mucosa. The mucosa is an
epithelial layer that lines
the lumen.
Submucosa. The submucosa is
a matrix of connective tissue
that contains blood vessels
and nerves.
Muscularis. The muscularis consists
mainly of smooth muscle tissue.
Serosa. External to the muscularis is the serosa,
a thin layer of connective and epithelial tissue.
0.2 mm
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Figure 40.8 Measuring metabolic rate
(a) This photograph shows a ghost crab in a
respirometer. Temperature is held constant in the
chamber, with air of known O2 concentration flowing through. The crab’s metabolic rate is calculated (b) Similarly, the metabolic rate of a man
fitted with a breathing apparatus is
from the difference between the amount of O2
being monitored while he works out
entering and the amount of O2 leaving the
on a stationary bike.
respirometer. This crab is on a treadmill, running
at a constant speed as measurements are made.
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Figure 40.10 Energy budgets for four animals
Annual energy expenditure (kcal/yr)
Endotherms
800,000
Reproduction
Basal
metabolic
rate
Ectotherm
Temperature
regulation costs
Growth
Activity
costs
340,000
8,000
4,000
60-kg female human
from temperate climate
4-kg male Adélie penguin
from Antarctica (brooding)
(a) Total annual energy expenditures
0.025-kg female deer mouse
from temperate
North America
4-kg female python
from Australia
Energy expenditure per unit mass
(kcal/kg•day)
438
Human
233
Python
Deer mouse
Adélie penguin
(b) Energy expenditures per unit mass (kcal/kg•day)
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36.5
5.5
Figure 40.11 A nonliving example of negative
feedback: control of room temperature
Response
No heat
produced
Heater
turned
off
Room
temperature
decreases
Too
hot
Set
point
Too
cold
Set
point
Set point
Control center:
thermostat
Room
temperature
increases
Heater
turned
on
Response
Heat
produced
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Figure 40.12 The relationship between body temperature and
environmental temperature in an aquatic endotherm and ectotherm
40
Body temperature (°C)
River otter (endotherm)
30
20
Largemouth bass (ectotherm)
10
0
10
20
30
Ambient (environmental) temperature (°C)
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40
Figure 40.13 Heat exchange between an organism
and its environment
Radiation is the emission of electromagnetic
waves by all objects warmer than absolute
zero. Radiation can transfer heat between
objects that are not in direct contact, as when
a lizard absorbs heat radiating from the sun.
Convection is the transfer of heat by the
movement of air or liquid past a surface,
as when a breeze contributes to heat loss
from a lizard’s dry skin, or blood moves
heat from the body core to the extremities.
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Evaporation is the removal of heat from the surface of a
liquid that is losing some of its molecules as gas.
Evaporation of water from a lizard’s moist surfaces that
are exposed to the environment has a strong cooling effect.
Conduction is the direct transfer of thermal motion (heat)
between molecules of objects in direct contact with each
other, as when a lizard sits on a hot rock.
Figure 40.14 Mammalian integumentary system
Hair
Epidermis
Sweat
pore
Muscle
Dermis
Nerve
Sweat
gland
Hypodermis
Adipose tissue
Blood vessels
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Oil gland
Hair follicle
Figure 40.18 A terrestrial mammal bathing, an
adaptation that enhances evaporative cooling
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Figure 40.21 The thermostat function of the
hypothalamus in human thermoregulation
Sweat glands secrete
sweat that evaporates,
cooling the body.
Thermostat in
hypothalamus
activates cooling
mechanisms.
Increased body
temperature (such
as when exercising
or in hot
surroundings)
Blood vessels
in skin dilate:
capillaries fill
with warm blood;
heat radiates from
skin surface.
Body temperature
decreases;
thermostat
shuts off cooling
mechanisms.
Homeostasis:
Internal body temperature
of approximately 36–38C
Body temperature
increases;
thermostat
shuts off warming
mechanisms.
Decreased body
temperature
(such as when
in cold
surroundings)
Blood vessels in skin
constrict, diverting blood
from skin to deeper tissues
and reducing heat loss
from skin surface.
Skeletal muscles rapidly
contract, causing shivering,
which generates heat.
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Thermostat in
hypothalamus
activates
warming
mechanisms.