basic principles of animal form and functionocw.nthu.edu.tw/ocw/upload/17/342/【l09...

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


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


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


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


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


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


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


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


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


• 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


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


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


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


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


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


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


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


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


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