2. Problem Solving
Animals must solve basic challenges of life:
Obtain oxygen
Nourish themselves
Excrete waste products
Move
These questions will be addressed throughout
our next unit.
Unifying themes that will be introduced here:
Form & function are closely related
3. Vocabulary
Anatomy – is the study of the structure of an
organism
Physiology – is the study of the functions an
organism performs
Bioenergetics – how organisms obtain,
process, and use their energy resources.
Homeostasis – regulating internal
temperature
4. 40.1
Physical laws and the
environment constrain
animal size and shape.
An animal’s size and
shape (body plan or
design) affect the way
it interacts with its
environment.
5. Physical Laws
Physical laws and the need to exchange
materials with the environment place certain
limits on the range of animals forms.
Examples: Aquatic animals (sleek streamlined
body forms) and flying animals (bones that allow
for the organism to generate enough lift to
become air born)
6. Exchange with the
environment
Living cells must be bathed in a aqueous
medium to keep the plasma membrane intact
Single celled organisms – Surface-to-volume ratio
Fig. 40.3a
7. Multicellular organisms
Composed of numerous
cells which also must be in
water
Saclike body plan
Hydra Fig. 40.3b
Flat body plan –
tapeworm
8.
9. Both of these put a large surface area in
contact with the environment but do NOT
allow for complexity in internal organization
Complex body forms allow for: outer
coverings to protect against predators, large
muscles for fast movement internal digestive
organs to break down food gradually,
maintaining relatively stable internal
environment, and for living on land.
10. Animal form and function are correlated at all
levels of organization.
Tissues are classified into 4 main categories –
11. Epithelial
Sheets of tightly packed cells
Where is it found? Epithelial tissue covers the
outside of the body and lines organs and
cavities within the body
Form & function? Closely joined (tight
junctions between them) so epithelium
functions as a barrier against mechanical
injury, microbes, and fluid loss.
12.
13. Types?
Stratified columnar
Simple columnar
Pseudostratified ciliated columnar
Stratified squamous
Simple squamous
Cuboidal
All have slightly different volumes of
cytoplasm which allow them to perform
different functions.
14. Connective Tissue
Sparse population of cells scattered through
an extracellular matrix.
Where is it found? Everywhere
Form & function? Bind and support other
tissues
18. Muscles tissue
Long cells called muscle fibers
Where is it found? Everywhere!! Most
abundant tissue in most animals
Form & function? Contraction brings about
movement
23. Animals use the chemical energy in food to
sustain form and function
Bioenergetics – limits the animal’s behavior,
growth, and reproduction and determines
how much food it needs.
24. – After the energetic needs of staying alive
are met any remaining molecules from food
can be used in biosynthesis (body growth &
repair, storage material such as fat and
production of gametes)
25.
26. Metabolic rate – the sum of all the energy-
requiring biochemical reactions occurring
over a given time interval.
Energy measured in Calories (cal) or kilocalories
(kcal)
Unit Calorie with a capital C is actually a kilocalorie
Energy appears as heat so metabolic rate can be
determined by measuring heat.
27. 2 Bioenergetic Strategies
Endothermic – bodies are warmed mostly by
heat generated by matabolism and body
temperature is maintained within a relatively
narrow range.
Ectothermic – meaning that they gain their
heat mostly from external sources
31. Influences on metabolic
rate
Size and metabolic rate: amount of energy it
takes to maintain each gram of body weight
is inversely related to body size. (Example –
each gram of a mouse requires about 20
times more calories than a gram of an
elephant)
32.
33. Activity and metabolic rate: every animal
experiences a range of metabolic rates. Basal
Metabolic rate (BMR) – metabolic rate of a
nongrowing endotherm that is at rest, has an
empty stomach, and is not experiencing
stress.
1,600-1,800 kcal per day for adult male
1,300-1,500 kcal per day for adult female
34. Standard Metabolic rate (SMR) – metabolic rate of a
resting, fasting, nonstressed ectotherm at a
particular temperature.
Maximum potential metabolic rates and ATP sources
36. 40.4
Many animals regulate their internal
environment within relatively narrow limits
Interstitial fluid (Bernard more than a century
ago) – internal environment of vertebrates –
today homeostasis – steady state
37. Regulators vs. Conformers
Regulators – animal is a regulator for a
particular environmental variable is it uses
internal control mechanisms to moderate
internal change in the face of external
fluctuation
38. Conformer – an animal is said to be a
conformer for a particular environmental
variable if it allows its internal condition to
vary with certain external changes
Regulators and conformers are extremes and
no animal is a perfect regulator or conformer
Some animals may regulate some internal
conditions and conform to external
conditions for others.
39. Mechanisms of Homeostasis
Negative feedback – thermostat in your
house pg. 832 Fig. 40.1
Positive feedback – amplify rather than
reverse the change (child birth)
40.
41. Thermoregulation – process by which animals
maintain an internal temperature within a
tolerable range. Critical because most
biological processes work best at optimal
conditions (plasma membrane)
42. Ectotherms vs. Endotherms
Ectotherms include invertebrates, fishes,
amphibians, lizards, snakes, and turtles
The amount of heat they generate has little effect
on body temperature
Bask in the sun to warm
Seek shade to cool
Can tolerate greater variation in internal
temperature than endotherms
Not “cold-blooded”
43. Endotherms include mammals, birds, some
fish, and numerous insect species
Can use metabolic heat to regulate body
temperature
Sweating to cool
Not “warm-blooded”
44. Advantages & Disadvantages
Advantages – able to generate a large amount of
heat metabolically – can perform vigorous activity
for much longer than is possible for most
ectotherms, can tolerate extreme temperatures
Disadvantages – energetically expensive – requires
more food
47. Balancing heat loss & gain
Insulation
Circulatory adaptations
Cooling by evaporative heat loss
Behavioral responses
Adjusting metabolic heat production
50. Circulatory adaptations
Vasodilation (warms skin) – increases in
diameter of superficial blood vessels
Vasoconstriction (cools skin) – reduces blood
flow and heat transfer by decreasing the
diameter of superficial blood vessels
Countercurrent heat exchanger – important
for reducing heat loss in many endotherms
51.
52.
53. Cooling by evaporative heat
loss
Water absorbs considerable heat when it
evaporates
Panting
Sweat glands
Spreading saliva on body surface
58. Adjusting metabolic heat
production
Endotherms must counteract constant heat
loss
Heat production is increased by shivering
NST – nonshivering thermogenesis (produce
heat instead of ATP)
60. Acclimatization – both ectotherms and
endotherms can adjust to new range of
environmental temperatures.
Shedding, growing a thicker coat
Heat shock proteins – help maintain integrity of
cell’s proteins when exposed to extreme heat so
they don’t denature
61.
62. Torpor & energy
conservation
Torpor – a physiological state in which
activity is low and metabolism decreases
Hibernation – long term torpor to winter cold and
food scarcity
Estivation – summer torpor
Daily torpor – adapted to feeding patterns