Transcript (b) Two cell layers

Chapter 32 An Introduction to Animal Diversity
1. What is an animal?
- Multicellular, heterotrophic eukaryote – ingestion
- Structural support from structural proteins – NOT cell walls
- Nervous tissue & muscle tissue for impulse conduction & movement
- Sexual reproduction with motile sperm swimming to non-motile egg
Chapter 40: Basic Principles of Animal Form & Function
1. What is an animal?
2. 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
Mouth
Diffusion
Gastrovascular
cavity
Diffusion
Diffusion
(a) Single cell
(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)
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).
Chapter 40: Basic Principles of Animal Form & Function
1. What is an animal?
2. How has exchange with the environment evolved?
- Simple diffusion from direct contact w/ environment
- To internal exchange thru moist medium
3. Reminder…what is the hierarchy of biological organization?
Atomsmoleculesorganellescellstissuesorgansorgan systems…
4. What is a tissue & what are the 4 types?
- Group of cells in a matrix with a common structure & function
- Epithelial
- Tightly packed sheets that cover the body, line organs & cavities w/in the body
-
-
-
- Involved with secretion & absorption
Connective
- Binds & supports other tissues
- 3 kinds - collagenous, elastic, reticular
Muscular
- Long cells made of contractile proteins (actin & myosin)
- 3 kinds - skeletal, smooth, cardiac
Nervous
- Sense stimuli & transmits signals
- Neuron – basic unit/cell
Chapter 40: Basic Principles of Animal Form & Function
1.
2.
3.
4.
5.
What is an animal?
How has exchange with the environment evolved?
Reminder…what is the hierarchy of biological organization?
What is a tissue & what are the 4 types?
What is metabolism?
- All of the chemical rxns within an organism
- Catabolism – hydrolysis breaks bonds – releases energy – exergonic
- Anabolism – dehydration rxns forms bonds – requires energy – endergonic
Figure 40.7 Bioenergetics of an animal: an overview
Organic molecules
in food
External
environment
Animal
body
Digestion and
absorption
Heat
Nutrient molecules
in body cells
Carbon
skeletons
Cellular
respiration
Energy
lost in
feces
Energy
lost in
urine
Heat
ATP
Biosynthesis:
growth,
storage, and
reproduction
Heat
Cellular
work
Heat
Chapter 40: Basic Principles of Animal Form & Function
1.
2.
3.
4.
5.
What is an animal?
How has exchange with the environment evolved?
Reminder…what is the hierarchy of biological organization?
What is a tissue & what are the 4 types?
What is metabolism?
- All of the chemical rxns within an organism
- Catabolism – hydrolysis breaks bonds – releases energy – exergonic
- Anabolism – dehydration rxns forms bonds – requires energy – endergonic
6. 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
Response
No heat
produced
Heater
turned
off
Room
temperature
decreases
Set point is maintained
Too
hot
Set
point
Too
cold
Set
point
Set point
Control center:
thermostat
Room
temperature
increases
Heater
turned
on
Response
Heat
produced
Chapter 40: Basic Principles of Animal Form & Function
1.
2.
3.
4.
5.
6.
What is an animal?
How has exchange with the environment evolved?
Reminder…what is the hierarchy of biological organization?
What is a tissue & what are the 4 types?
What is metabolism?
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 direction
7. 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
40
Body temperature (°C)
River otter (endotherm)
30
20
Largemouth bass (ectotherm)
10
0
10
20
30
Ambient (environmental) temperature (°C)
40
Chapter 40: Basic Principles of Animal Form & Function
1.
2.
3.
4.
5.
6.
7.
What is an animal?
How has exchange with the environment evolved?
Reminder…what is the hierarchy of biological organization?
What is a tissue & what are the 4 types?
What is metabolism?
What is homeostasis & how is it achieved?
What are the 2 types of thermoregulation?
Chapter 40: Basic Principles of Animal Form & Function
1.
2.
3.
4.
5.
6.
7.
8.
What is an animal?
How has exchange with the environment evolved?
Reminder…what is the hierarchy of biological organization?
What is a tissue & what are the 4 types?
What is metabolism?
What is homeostasis & how is it achieved?
What are the 2 types of thermoregulation?
How can organisms exchange heat within their bodies?
- Countercurrent heat exchange
Figure 40.15 Countercurrent heat exchangers
1 Arteries carrying warm blood down the
legs of a goose or the flippers of a dolphin
are in close contact with veins conveying
cool blood in the opposite direction, back
toward the trunk of the body. This
arrangement facilitates heat transfer
from arteries to veins (black
arrows) along the entire length
of the blood vessels.
Canada
goose
Artery
1
35°C
30º
2 Near the end of the leg or flipper, where
arterial blood has been cooled to far below
the animal’s core temperature, the artery
Vein
can still transfer heat to the even colder
3
blood of an adjacent vein. The venous blood
33°
continues to absorb heat as it passes warmer
and warmer arterial blood traveling in the
opposite direction.
27º
20º
18º
10º
9º
2
Pacific
bottlenose
dolphin
1
3
Blood flow
3
Vein
Artery
2
3 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 parts
immersed in cold water.
In the flippers of a dolphin, each artery is
surrounded by several veins in a
countercurrent arrangement, allowing
efficient heat exchange between arterial
and venous blood.
Chapter 40: Basic Principles of Animal Form & Function
1.
2.
3.
4.
5.
6.
7.
8.
9.
What is an animal?
How has exchange with the environment evolved?
Reminder…what is the hierarchy of biological organization?
What is a tissue & what are the 4 types?
What is metabolism?
What is homeostasis & how is it achieved?
What are the 2 types of thermoregulation?
How can organisms exchange heat within their bodies?
How do we achieve homeostasis for body temperature?
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.
Thermostat in
hypothalamus
activates
warming
mechanisms.
Chapter 40: Basic Principles of Animal Form & Function
1. What is an animal?
2. How has exchange with the environment evolved?
3. Reminder…what is the hierarchy of biological organization?
4. What is a tissue & what are the 4 types?
5. What is metabolism?
6. What is homeostasis & how is it achieved?
7. What are the 2 types of thermoregulation?
8. How do organisms exchange heat with their environment?
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 be
necessary to stay active in winter
Temperature (°C)
Metabolic rate
(kcal per day)
200
Actual
metabolism
100
0
35
30
25
Arousals
Body
temperature
20
15
10
5
0
-5
-10
-15
Outside
temperature
June
August
Burrow
temperature
October
December
February
April