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
olic
rate
(kca
l per
day
)
200
100
0
35
30252015105
0
-5-10-15