basic principles of animal form and functionocw.nthu.edu.tw/ocw/upload/17/342/【l09...
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
PowerPoint® Lecture Presentations for
BiologyEighth Edition
Neil Campbell and Jane Reece
Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp
Chapter 40
Basic Principles of Animal
Form and Function
Key concepts
Organization of animal form and function
Homeostasis (balance): temperature, energy
Overview: Diverse Forms, Common Challenges
• Anatomy is the study of the biological form of
an organism
• Physiology is the study of the biological
functions an organism performs
• The comparative study of animals reveals that
form and function are closely correlated
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-1
Concept 40.1: Animal form and function are correlated at all levels of organization
• Size and shape affect the way an animal
interacts with its environment
• Many different animal body plans have evolved
and are determined by the genome
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Physical Constraints on Animal Size and Shape
• The ability to perform certain actions depends
on an animal’s shape, size, and environment
• Evolutionary convergence reflects different
species’ adaptations to a similar environmental
challenge
• Physical laws impose constraints on animal
size and shape
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-2
(a) Tuna
(b) Penguin
(c) Seal
Physical Constraints on Animal Size and Shape
Fig. 40-3
Exchange
0.15 mm
(a) Single cell
1.5 mm
(b) Two layers of cells
Exchange
Exchange
Mouth
Gastrovascularcavity
Exchange with the Environment
Fig. 40-4
0.5 cmNutrients
Digestive
system
Lining of small intestine
MouthFood
External environment
Animalbody
CO2 O2
Circulatorysystem
Heart
Respiratorysystem
Cells
Interstitialfluid
Excretory
system
Anus
Unabsorbedmatter (feces)
Metabolic waste products(nitrogenous waste)
Kidney tubules
10 µm
50 µ
m
Lung tissue
More complex organisms have highly folded internal surfaces for exchanging materials
In vertebrates, the space between cells is filled with interstitial fluid,
which allows for the movement of material into and out of cells
• Most animals are composed of specialized
cells organized into tissues that have different
functions
• Tissues make up organs, which together make
up organ systems
Hierarchical Organization of Body Plans
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Table 40-1
• Different tissues have different structures that
are suited to their functions
• Tissues are classified into four main categories:
epithelial, connective, muscle, and nervous
Tissue Structure and Function
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Fig. 40-5a
Epithelial Tissue
Cuboidal
epitheliumSimple
columnar
epithelium
Pseudostratified
ciliated
columnar
epithelium
Stratified
squamous
epithelium
Simple
squamous
epithelium
Fig. 40-5b
Apical surface
Basal surface
Basal lamina
40 µm
Fig. 40-5c
Connective Tissue
Collagenous fiber
Loose
connective
tissue
Elastic fiber12
0 µ
m
Cartilage
Chondrocytes
10
0 µ
m
Chondroitinsulfate
Adiposetissue
Fat droplets
15
0 µ
m
White blood cells
55
µm
Plasma Red bloodcells
Blood
Nuclei
Fibrous
connective
tissue
30
µm
Osteon
Bone
Central canal
70
0 µ
m
Fig. 40-5j
Muscle Tissue
50 µmSkeletalmuscle
Multiplenuclei
Muscle fiber
Sarcomere
100 µm
Smoothmuscle
Cardiac muscle
Nucleus
Musclefibers
25 µm
Nucleus Intercalateddisk
Fig. 40-5n
Glial cells
Nervous Tissue
15 µm
Dendrites
Cell body
Axon
Neuron
Axons
Blood vessel
40 µm
Fig. 40-6Stimulus
Hormone
Endocrinecell
Signal travelseverywherevia the bloodstream.
Bloodvessel
Response
(a) Signaling by hormones
Stimulus
Neuron
Axon
Signal
Signal travelsalong axon toa specificlocation.
Signal
Axons
Response
(b) Signaling by neurons
Control and coordination
Fig. 40-7
River otter (temperature regulator)
Largemouth bass(temperature conformer)
Bo
dy t
em
pera
ture
(°C
)
0 10
10
20
20
30
30
40
40
Ambient (environmental) temperature (ºC)
Homeostasis
• Organisms use homeostasis to maintain a
“steady state” or internal balance regardless of
external environment
• In humans, body temperature, blood pH, and
glucose concentration are each maintained at a
constant level
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-8Response:Heater turnedoff
Stimulus:Control center(thermostat)reads too hot
Roomtemperaturedecreases
Setpoint:20ºC
Roomtemperature
increases
Stimulus:Control center(thermostat)
reads too cold
Response:Heater turnedon
sensor
sensor
Feedback Loops in Homeostasis
• The dynamic equilibrium of homeostasis is
maintained by negative feedback, which helps
to return a variable to either a normal range or
a set point
• Most homeostatic control systems function by
negative feedback, where buildup of the end
product shuts the system off
• Positive feedback loops occur in animals, but
do not usually contribute to homeostasis
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Alterations in Homeostasis
• Set points and normal ranges can change with
age or show cyclic variation
• Homeostasis can adjust to changes in external
environment, a process called acclimatization
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Concept 40.3: Homeostatic processes for thermoregulation involve form, function, and behavior
• Thermoregulation is the process by which
animals maintain an internal temperature within
a tolerable range
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• Endothermic animals generate heat by
metabolism; birds and mammals are
endotherms
• Ectothermic animals gain heat from external
sources; ectotherms include most invertebrates,
fishes, amphibians, and non-avian reptiles
Endothermy and Ectothermy
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Fig. 40-9
(a) A walrus, an endotherm
(b) A lizard, an ectotherm
Variation in Body Temperature
• The body temperature of a poikilotherm varies
with its environment, while that of a
homeotherm is relatively constant
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Fig. 40-10
Radiation Evaporation
Convection Conduction
Organisms exchange
heat by four physical
processes
• Five general adaptations help animals
thermoregulate:
– Insulation
– Circulatory adaptations
– Cooling by evaporative heat loss
– Behavioral responses
– Adjusting metabolic heat production
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Fig. 40-11
Epidermis
Dermis
Hypodermis
Adipose tissue
Blood vessels
Hair
Sweatpore
Muscle
Nerve
Sweatgland
Oil gland
Hair follicle
Heat regulation in mammals often
involves the integumentary
system: skin, hair, and nails
Fig. 40-12
Canada goose Bottlenosedolphin
Artery
Artery
Vein Vein
Blood flow
33º35ºC
27º30º
18º20º
10º 9º
countercurrent exchange
Fig. 40-13
Some terrestrial
invertebrates have
postures that minimize or
maximize absorption of
solar heat
Fig. 40-14
RESULTS
Contractions per minute
O2
co
ns
um
pti
on
(m
L O
2/h
r) p
er
kg
00
20
2015105 25 30 35
40
60
80
100
120
animals can regulate body temperature by
adjusting their rate of metabolic heat production
Fig. 40-15
PREFLIGHT PREFLIGHTWARM-UP
FLIGHT
Thorax
Abdomen
Time from onset of warm-up (min)
Te
mp
era
ture
(ºC
)
0 2 4
25
30
35
40
• Birds and mammals can vary their insulation to
acclimatize to seasonal temperature changes
• When temperatures are subzero, some
ectotherms produce “antifreeze” compounds to
prevent ice formation in their cells
Acclimatization in Thermoregulation
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Fig. 40-16Sweat 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.
Fever is the result of a
change to the set point for
a biological thermostat
Fig. 40-17
Organic moleculesin foodExternal
environment
Animalbody Digestion and
absorption
Nutrient moleculesin body cells
Carbonskeletons
Cellularrespiration
ATP
Heat
Energy lostin feces
Energy lost innitrogenouswaste
Heat
Biosynthesis
Heat
Heat
Cellularwork
Bioenergetics is the
overall flow and
transformation of energy
in an animal
• Metabolic rate is the amount of energy an
animal uses in a unit of time
• One way to measure it is to determine the
amount of oxygen consumed or carbon dioxide
produced
Quantifying Energy Use
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Fig. 40-18
Minimum Metabolic Rate and Thermoregulation
• Basal metabolic rate (BMR) is the metabolic rate of an endotherm at rest at a “comfortable” temperature
• Standard metabolic rate (SMR) is the metabolic rate of an ectotherm at rest at a specific temperature
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-19
Elephant
Horse
Human
Sheep
DogCat
Rat
Ground squirrel
Mouse
Harvest mouse
Shrew
Body mass (kg) (log scale)
BM
R (
L O
2/h
r) (
Iog
scale
)
10–3 10–210–2
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 CatDog
Human
Horse
Elephant
BM
R (
L O
2/h
r) (
per
kg
)
Ground squirrel
Body mass (kg) (log scale)
10–3 10–2 10–1 1 10 102 1030
1
2
3
4
5
6
8
7
(b) Relationship of BMR per kilogram of body mass to body size
Size and Metabolic Rate
Fig. 40-20
An
nu
al
en
erg
y e
xp
en
dit
ure
(kcal/h
r)
60-kg female humanfrom temperate climate
800,000
Basal
(standard)
metabolism
ReproductionThermoregulation
Growth
Activity
340,000
4-kg male Adélie penguinfrom Antarctica (brooding)
4,000
0.025-kg female deer mousefrom temperateNorth America
8,000
4-kg female easternindigo snake
Endotherms Ectotherm
Energy Budgets
Torpor and Energy Conservation
• Torpor is a physiological state in which activity
is low and metabolism decreases
• Torpor enables animals to save energy while
avoiding difficult and dangerous conditions
• Hibernation is long-term torpor that is an
adaptation to winter cold and food scarcity
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Fig. 40-21
Additional metabolism that would benecessary to stay active in winterActual
metabolism
Arousals
Bodytemperature
Outsidetemperature
Burrowtemperature
Meta
bo
lic r
ate
(kc
al p
er
da
y)
Te
mp
era
ture
(°C
)
June August October December February April–15
–10
–5
0
5
15
10
25
20
35
30
0
100
200
• Estivation, or summer torpor, enables animals
to survive long periods of high temperatures
and scarce water supplies
• Daily torpor is exhibited by many small
mammals and birds and seems adapted to
feeding patterns
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You should now be able to:
1. Distinguish among the following sets of terms:
collagenous, elastic, and reticular fibers;
regulator and conformer; positive and
negative feedback; basal and standard
metabolic rates; torpor, hibernation, estivation,
and daily torpor
2. Relate structure with function and identify
diagrams of the following animal tissues:
epithelial, connective tissue (six types),
muscle tissue (three types), and nervous
tissueCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
3. Compare and contrast the nervous and endocrine systems
4. Define thermoregulation and explain how endotherms and ectotherms manage their heat budgets
5. Describe how a countercurrent heat exchanger may function to retain heat within an animal body
6. Define bioenergetics and biosynthesis
7. Define metabolic rate and explain how it can be determined for animals
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings