Chapter 40: Basic Principles of Animal Form & Function

Test corrections – due WednesdayWe are counting down the days so stay focussed.

(a) Tuna

(b) Shark

(c) Penguin

(d) Dolphin

(e) Seal

Chapter 40: Basic Principles of Animal Form & Function

Evolutionary convergence in fast swimmers

Chapter 40: Basic Principles of Animal Form & Function1. How has exchange with the environment evolved?

- Simple diffusion from direct contact w/ environment- To internal exchange thru moist medium

Figure 40.3 Contact with the environment

Diffusion

(a) Single cell

Mouth

Gastrovascularcavity

Diffusion

Diffusion

(b) Two cell layers

Figure 40.4 Internal exchange surfaces of complex animals

External environment

Food CO2 O2

MouthAnimalbody

Respiratorysystem

Circulatorysystem

Nutrients

Excretorysystem

Digestivesystem

Heart

Blood

Cells

Interstitialfluid

Anus

Unabsorbedmatter (feces)

Metabolic wasteproducts (urine)

The lining of the small intestine, a diges-tive organ, is elaborated with fingerlikeprojections that expand the surface areafor nutrient absorption (cross-section, SEM).

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).

Inside a kidney is a mass of microscopic tubules that exhange chemicals with blood flowing through a web of tiny vessels called capillaries (SEM).

0.5 cm

10 µm

50 µ

m

Chapter 40: Basic Principles of Animal Form & Function1. How has exchange with the environment evolved?

- Simple diffusion from direct contact w/ environment- To internal exchange thru moist medium

2. Reminder…what is the hierarchy of biological organization?Atomsmoleculesorganellescellstissuesorgansorgan systems…

3. What is a tissue & what are the 4 types?- Group of cells in a matrix with a common structure & function - Epithelial - Connective- Muscular - Nervous

EPITHELIAL TISSUEColumnar epithelia, which have cells with relatively large cytoplasmic volumes, are often located where secretion or active absorption of substances is an important function.

A stratified columnar epithelium

A simple columnar epithelium A pseudostratified

ciliated columnarepithelium

Stratified squamous epithelia

Simple squamous epitheliaCuboidal epithelia

Basement membrane

40 µm- Epithelial Tissue- Tightly packed sheets that cover the body, line organs & cavities w/in the body- Involved with secretion & absorption

CollagenousfiberElasticfiber

ChondrocytesChondroitinsulfate

Loose connective tissue

Fibrous connective tissue

100

µm

100 µm

Nuclei

30 µm

Bone Blood

Centralcanal

Osteon

700 µm 55 µm

Red blood cellsWhite blood cell

Plasma

Cartilage

Adipose tissue

Fat droplets

150

µm

CONNECTIVE TISSUE

- Connective Tissue- Binds & supports other tissues- 3 types

- Collagenous - non-elastic – skin won’t rip

- Elastic - elastin – skin reshapes

- Reticular - Thin & branched- Made of collagen- Joins connective tissue

to neighboring tissue

MUSCLE TISSUE

Skeletal muscle100 µm

Multiple nuclei

Muscle fiber

Sarcomere

Cardiac muscle

Nucleus Intercalateddisk

50 µm

Smooth muscle Nucleus

Musclefibers

25 µm

NERVOUS TISSUE

Neurons Process

Cell body

Nucleus

50 µm

Muscle tissue (ch 49)- Long cells made of contractile proteins- Actin & myosin- 3 kinds

- Skeletal – aka striated (w/ lines)- Cardiac – heart – branched cells- Smooth

- no striations- In walls of digestive tract,

bladder, arteries

Nervous tissue (ch 48)- Sense stimuli & transmits signals- neuron

Chapter 40: Basic Principles of Animal Form & Function1. How has exchange with the environment evolved?2. Reminder…what is the hierarchy of biological organization?3. What is a tissue & what are the 4 types?4. What is metabolism?

- All of the chemical rxns within an organism- Catabolism – breaks bonds – releases energy – exergonic- Anabolism – forms bonds – requires energy – endergonic

Figure 40.7 Bioenergetics of an animal: an overview

Organic moleculesin food

Digestion andabsorption

Nutrient moleculesin body cells

Cellularrespiration

Biosynthesis:growth,

storage, andreproduction

Cellularwork

Heat

Energylost infeces

Energylost inurine

Heat

Heat

Externalenvironment

Animalbody

Heat

Carbonskeletons

ATP

Chapter 40: Basic Principles of Animal Form & Function1. How has exchange with the environment evolved?2. Reminder…what is the hierarchy of biological organization?3. What is a tissue & what are the 4 types?4. What is metabolism?

- All of the chemical rxns within an organism- Catabolism – breaks bonds – releases energy – exergonic- Anabolism – forms bonds – requires energy – endergonic

5. What is homeostasis & how is it achieved?- Steady state- Negative feedback

- the response is in the opposite direction of the stimulus

Figure 40.11 A nonliving example of negative feedback: control of room temperature

ResponseNo heat

produced

Roomtemperaturedecreases

Heaterturnedoff

Set point

Toohot

Setpoint

Control center:thermostat

Roomtemperatureincreases

Heaterturnedon

Toocold

ResponseHeat

produced

Setpoint

Set point is maintained

Chapter 40: Basic Principles of Animal Form & Function1. How has exchange with the environment evolved?2. Reminder…what is the hierarchy of biological organization?3. What is a tissue & what are the 4 types?4. What is metabolism?

- All of the chemical rxns within an organism- Catabolism – breaks bonds – releases energy – exergonic- Anabolism – forms bonds – requires energy – endergonic

5. What is homeostasis & how is it achieved?- Steady state- Negative feedback

- the response is in the opposite direction of the stimulus- Positive feedback

- Response & stimulus are in the same direction6. What are the 2 types of thermoregulation?

- Ectothermic – heat & metabolism based on environment- Endothermic – heat & metabolism regulated internally

Figure 40.12 The relationship between body temperature and environmental temperature in an aquatic endotherm and ectotherm

River otter (endotherm)

Largemouth bass (ectotherm)

Ambient (environmental) temperature (°C)

Bod

y te

mpe

ratu

re (°

C)

40

30

20

10

10 20 30 400

Chapter 40: Basic Principles of Animal Form & Function1. How has exchange with the environment evolved?2. Reminder…what is the hierarchy of biological organization?3. What is a tissue & what are the 4 types?4. What is metabolism?5. What is homeostasis & how is it achieved?6. What are the 2 types of thermoregulation?7. How do organisms exchange heat with their environment?

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.

Evaporation is the removal of heat from the surface of aliquid 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.

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.

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.

Chapter 40: Basic Principles of Animal Form & Function1. How has exchange with the environment evolved?2. Reminder…what is the hierarchy of biological organization?3. What is a tissue & what are the 4 types?4. What is metabolism?5. What is homeostasis & how is it achieved?6. What are the 2 types of thermoregulation?7. How do organisms exchange heat with their environment?8. How can organisms exchange heat within their bodies?

- Countercurrent heat exchange

Figure 40.15 Countercurrent heat exchangersArteries carrying warm blood down thelegs of a goose or the flippers of a dolphinare in close contact with veins conveyingcool blood in the opposite direction, backtoward the trunk of the body. Thisarrangement facilitates heat transferfrom arteries to veins (blackarrows) along the entire lengthof the blood vessels.

Near the end of the leg or flipper, wherearterial blood has been cooled to far below the animal’s core temperature, the artery can still transfer heat to the even colderblood of an adjacent vein. The venous bloodcontinues to absorb heat as it passes warmer and warmer arterial blood traveling in the opposite direction.

As the venous blood approaches the center of the body, it is almost as warm as the body core, minimizing the heat lost as a result of supplying blood to body partsimmersed in cold water.

In the flippers of a dolphin, each artery issurrounded by several veins in acountercurrent arrangement, allowingefficient heat exchange between arterialand venous blood.

Canadagoose

Artery Vein

35°C

Blood flow

VeinArtery

30º

20º

10º

33°

27º

18º

9º

Pacific bottlenose dolphin

1

2

3

2

1 3

1

3

2

3

Chapter 40: Basic Principles of Animal Form & Function1. How has exchange with the environment evolved?2. Reminder…what is the hierarchy of biological organization?3. What is a tissue & what are the 4 types?4. What is metabolism?5. What is homeostasis & how is it achieved?6. What are the 2 types of thermoregulation?7. How do organisms exchange heat with their environment?8. How can organisms exchange heat within their bodies?9. How do we achieve homeostasis for body temperature?

Figure 40.21 The thermostat function of the hypothalamus in human thermoregulation Thermostat in

hypothalamusactivates coolingmechanisms.

Sweat glands secrete sweat that evaporates, cooling the body.

Blood vesselsin skin dilate:capillaries fillwith warm blood;heat radiates fromskin surface. Body temperature

decreases;thermostat

shuts off coolingmechanisms.

Increased bodytemperature (suchas when exercising

or in hotsurroundings)

Homeostasis:Internal body temperatureof approximately 36–38C

Body temperatureincreases;thermostat

shuts off warmingmechanisms.

Decreased bodytemperature

(such as whenin cold

surroundings)

Blood vessels in skinconstrict, diverting bloodfrom skin to deeper tissuesand reducing heat lossfrom skin surface.

Skeletal muscles rapidlycontract, causing shivering,which generates heat.

Thermostat inhypothalamusactivateswarmingmechanisms.

Chapter 40: Basic Principles of Animal Form & Function1. How has exchange with the environment evolved?2. Reminder…what is the hierarchy of biological organization?3. What is a tissue & what are the 4 types?4. What is metabolism?5. What is homeostasis & how is it achieved?6. What are the 2 types of thermoregulation?7. How do organisms exchange heat with their environment?8. How can organisms exchange heat within their bodies?9. How do we achieve homeostasis for body temperature?10. How do animals thermoregulate in temperature extremes?

- Torpor – physiological state in which activity is low & metabolism is decreased- Hibernation – winter – bears, Belding’s ground squirrels- Estivation – summer – many reptiles, bees

Figure 40.22 Body temperature and metabolism during hibernation in Belding’s ground squirrels

Additional metabolism that would benecessary to stay active in winter

Actualmetabolism

Bodytemperature

Arousals

Outsidetemperature Burrow

temperature

June August October December February April

Tem

pera

ture

(°C

)M

etab

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rate

(kca

l per

day

)

200

100

0

35

30252015105

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