Download Ch. 40 Lecture Chapter 40_Homeostasis

Basic Principles of Animal Form & Function
Big Ideas
• 1.B.1: Organisms share many conserved core
processes and features that evolved and are
widely distributed among organisms today.
• 2.C.1: Organisms use feedback mechanisms to
maintain their internal environments, respond to
external changes in environment.
• 4.A.6: Interactions among living systems and with
their environment result in the movement of matter
and energy.
Big Ideas
• 1.B.1: Organisms share many conserved core
processes and features that evolved and are widely
distributed among organisms today.
• 2.C.1: Organisms use feedback mechanisms to
maintain their internal environments, respond to
external changes in environment.
• 4.A.6: Interactions among living systems and with
their environment result in the movement of matter
and energy.
Big Ideas
• 1.B.1: Organisms share many conserved core
processes and features that evolved and are widely
distributed among organisms today.
• 2.C.1: Organisms use feedback mechanisms to
maintain their internal environments, respond to
external changes in environment.
• 4.A.6: Interactions among living systems and with
their environment result in the movement of
matter and energy.
Illustrative Examples:
• Cellular structural similarities across animal kingdom
• Methods of cellular control and regulation (e.g. hormones)
• Methods of cellular transport (e.g. diffusion, active transport)
• Temperature regulation in animals (e.g. negative feedback)
• Onset of labor in childbirth (e.g. positive feedback)
• Competition for resources, territoriality, health, predation,
accumulation of wastes  population controls (e.g. natural
selection)
Mix & Match Review: Ch. 40.1-2
© 2011 Pearson Education, Inc.
3, 6
1. C/C concepts of positive &
negative feedback
2. Describe one homeostatic system
including: set point, stimulus,
response, feedback type
2, 5, 8
1. Hierarchy of body plans
2. Describe main body tissues
1, 4, 7
1. C/C Physiology & Anatomy
2. Describe ways that internal,
external environments connect
3. Physical laws that influence
morphology (body shape & size)
Mix & Match Review: Ch. 40.1-2
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
homeostasis
system
exchange
cell
tissue
homeostasis
gas
free energy
+ feedback
organ system
1.
2.
3.
4.
5.
homeostasis
glucose concentration
information
form & function
hierarchy
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
© 2011 Pearson Education, Inc.
Figure 40.1
“Hay! Here are the key points…”
• Animal form and function are
correlated at all levels of
organization.
• Feedback control maintains the
internal environment in many
animals.
• Homeostatic processes for
thermoregulation involve form,
function, and behavior.
• Energy requirements are related to
animal size, activity, and
environment.
Key Point: 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
© 2011 Pearson Education, Inc.
Evolution of Animal Size and Shape
• Physical laws constrain strength, diffusion,
movement, and heat exchange
• As animals increase in size, their skeletons must
be proportionately larger to support their mass
• Evolutionary convergence reflects different
species’ adaptations to a similar environmental
challenge
© 2011 Pearson Education, Inc.
Figure 40.2
Seal
Penguin
Tuna
Figure 40.2a
Seal
Figure 40.2b
Penguin
Figure 40.2c
Tuna
Exchange with the Environment
• Materials such as nutrients, waste products,
and gases must be exchanged across the cell
membranes of animal cells
• The rate of exchange is proportional to a cell’s
surface area while amount of exchange material
is proportional to a cell’s volume. Huh?
© 2011 Pearson Education, Inc.
Figure 40.3
Mouth
Gastrovascular
cavity
Exchange
Exchange
Exchange
0.1 mm
1 mm
(a) Single cell
(b) Two layers of cells
• In flat animals such as tapeworms, the
distance between cells and the environment is
minimized
• More complex organisms have highly folded
internal surfaces for exchanging materials
© 2011 Pearson Education, Inc.
Figure 40.4a
External
environment
Food
CO2
Mouth
O2
Animal
body
Respiratory
system
Heart
Digestive
system
Nutrients
Cells
Interstitial
fluid
Circulatory
system
Excretory
system
Anus
Unabsorbed
matter (feces)
Metabolic waste products
(nitrogenous waste)
Figure 40.4
External environment
CO2 O
Food
2
Mouth
Respiratory
system
Heart
Interstitial
fluid
Circulatory
system
Anus
Unabsorbed
matter (feces)
Metabolic waste products
(nitrogenous waste)
50 m
Excretory
system
100 m
Lining of small
intestine (SEM)
Lung tissue (SEM)
Cells
Digestive
system
Nutrients
250 m
Animal
body
Blood vessels in
kidney (SEM)
100 m
Figure 40.4b
250 m
Lung tissue (SEM)
Lining of small
intestine (SEM)
Figure 40.4d
Blood vessels in
kidney (SEM)
50 m
Figure 40.4c
• In vertebrates, the space between cells is filled
with interstitial fluid, which allows for the
movement of material into and out of cells
• A complex body plan helps an animal living in a
variable environment to maintain a relatively
stable internal environment
© 2011 Pearson Education, Inc.
Hierarchical Organization of Body Plans
• Most animals are composed of specialized cells
organized into tissues that have different
functions
• Tissues make up organs, which together make
up organ systems
• Some organs, such as the pancreas, belong to
more than one organ system
© 2011 Pearson Education, Inc.
Table 40.1
Exploring Structure and Function in
Animal Tissues
• Different tissues have different structures that are
suited to their functions
• Tissues are classified into four main categories:
–
–
–
–
Epithelial,
Connective,
Muscle,
and Nervous
© 2011 Pearson Education, Inc.
Figure 40.5aa
Epithelial Tissue
Stratified squamous
epithelium
Cuboidal
epithelium
Simple columnar
epithelium
Simple squamous
epithelium
Pseudostratified
columnar
epithelium
Figure 40.5ba
Connective Tissue
Loose connective tissue
Blood
Collagenous fiber
Plasma
55 m
120 m
White
blood cells
Elastic fiber
Red blood cells
Cartilage
Fibrous connective tissue
30 m
100 m
Chondrocytes
Chondroitin sulfate
Nuclei
Adipose tissue
Central
canal
Fat droplets
Osteon
150 m
700 m
Bone
Figure 40.5ca
Muscle Tissue
Skeletal muscle
Nuclei
Muscle
fiber
Sarcomere
100 m
Smooth muscle
Nucleus
Muscle fibers
Cardiac muscle
25 m
Nucleus
Intercalated disk
50 m
Figure 40.5da
Nervous Tissue
Neurons
Glia
Glia
Neuron:
Dendrites
Cell body
Axons of
neurons
40 m
Axon
Blood
vessel
(Fluorescent LM)
(Confocal LM)
15 m
Coordination and Control
• Control and coordination within a body depend on
the endocrine system and the nervous system
• The endocrine system transmits chemical signals
called hormones to receptive cells throughout
the body via blood
• A hormone may affect one or more regions
throughout the body
• Hormones are relatively slow acting, but can
have long-lasting effects
© 2011 Pearson Education, Inc.
Illustrative Examples:
• Cellular structural similarities across animal kingdom
• Methods of cellular control and regulation (e.g. hormones)
• Methods of cellular transport (e.g. diffusion, active transport)
• Temperature regulation in animals (e.g. negative feedback)
• Onset of labor in childbirth (e.g. positive feedback)
• Competition for resources, territoriality, health, predation,
accumulation of wastes  population controls (e.g. natural
selection)
Figure 40.6
Figure 40.6a
• The nervous system transmits information
between specific locations
• The information conveyed depends on a signal’s
pathway, not the type of signal
• Nerve signal transmission is very fast
• Nerve impulses can be received by neurons,
muscle cells, endocrine cells, and exocrine
cells
© 2011 Pearson Education, Inc.
Figure 40.6b
“Hay! Here are the key points…”
• Animal form and function are
correlated at all levels of
organization.
• Feedback control maintains the
internal environment in many
animals.
• Homeostatic processes for
thermoregulation involve form,
function, and behavior.
• Energy requirements are related to
animal size, activity, and
environment.
Key Point: Feedback control maintains the internal
environment in many animals
• Animals manage their internal environment by
regulating or conforming to the external
environment
© 2011 Pearson Education, Inc.
Figure 40.7
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
© 2011 Pearson Education, Inc.
Mechanisms of Homeostasis
• Mechanisms of homeostasis moderate changes
in the internal environment
• For a given variable, fluctuations above or below
a set point serve as a stimulus; these are
detected by a sensor and trigger a response
• The response returns the variable to the set point
© 2011 Pearson Education, Inc.
Figure 40.8
Feedback Control in Homeostasis
Negative feedback
Positive feedback
• Helps to return a variable
to a normal range
• Most homeostatic control
systems function by
negative feedback, where
buildup of the end
product shuts the system
off
• amplifies a stimulus and
does not usually
contribute to homeostasis
in animals
• E.g. Childbirth
contractions
– Temperature
– Blood gases
– Blood sugar
© 2011 Pearson Education, Inc.
“Hay! Here are the key points…”
• Animal form and function are
correlated at all levels of
organization.
• Feedback control maintains the
internal environment in many
animals.
• Homeostatic processes for
thermoregulation involve form,
function, and behavior.
• Energy requirements are related to
animal size, activity, and
environment.
Illustrative Examples:
• Cellular structural similarities across animal kingdom
• Methods of cellular control and regulation (e.g. hormones)
• Methods of cellular transport (e.g. diffusion, active transport)
• Temperature regulation in animals (e.g. negative feedback)
• Onset of labor in childbirth (e.g. positive feedback)
• Competition for resources, territoriality, health, predation,
accumulation of wastes  population controls (e.g. natural
selection)
Mix & Match Review: Ch. 40.3
1.
2.
3.
4.
Regulator
Conformer
Negative feedback
Homeostasis
1, 4, 7
1.
2.
3.
4.
Ectotherm
Endotherm
Homeotherm
Poikilotherm
2, 5, 8
3, 6
1. ID, describe five
thermoregulatory
adaptations
Key Point: Homeostatic processes for thermoregulation
involve form, function, and behavior
• Thermoregulation is the process by which
animals maintain an internal temperature within a
tolerable range
© 2011 Pearson Education, Inc.
Endothermy and Ectothermy
• 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 nonavian reptiles
© 2011 Pearson Education, Inc.
• In general, ectotherms tolerate greater variation
in internal temperature, while endotherms are
active at a greater range of external temperatures
• Endothermy is more energetically expensive than
ectothermy. Why?
© 2011 Pearson Education, Inc.
Figure 40.10
Figure 40.10a
Figure 40.10b
Variation in Body Temperature
• The body temperature of a poikilotherm varies
with its environment
• The body temperature of a homeotherm is
relatively constant
• The relationship between heat source and body
temperature is not fixed (that is, not all
poikilotherms are ectotherms)
© 2011 Pearson Education, Inc.
Balancing Heat Loss and Gain
• Organisms exchange heat by four physical
processes:
–
–
–
–
Radiation
Evaporation
Convection
and Conduction
© 2011 Pearson Education, Inc.
Figure 40.11
• Heat regulation in mammals often involves the
integumentary system: skin, hair, and nails
• Five adaptations help animals thermoregulate:


Insulation (blubber, skin, feathers, fur)
Circulatory adaptations
(vasodilation/constriction; countercurrent exch.)


Cooling by evaporative heat loss (sweat)
Behavioral responses (shivering, migration,
basking)

Adjusting metabolic heat production (C.R.)
© 2011 Pearson Education, Inc.
Figure 40.12
Figure 40.13
Figure 40.14
Figure 40.15
Acclimatization in Thermoregulation
• Birds and mammals:
– can vary their insulation to acclimatize to seasonal
temperature changes
• Certain ectotherms:
– e.g. arctic fish produce “antifreeze” compounds to
prevent ice formation in their cells
© 2011 Pearson Education, Inc.
Physiological Thermostats and Fever
• Thermoregulation is controlled by a region of
the brain called the hypothalamus
• The hypothalamus triggers heat loss or heat
generating mechanisms
• Fever is the result of a change to the set point
for a biological thermostat
© 2011 Pearson Education, Inc.
Figure 40.16
Figure 40.16a
Figure 40.16b
“Hay! Here are the key points…”
• Animal form and function are
correlated at all levels of
organization.
• Feedback control maintains the
internal environment in many
animals.
• Homeostatic processes for
thermoregulation involve form,
function, and behavior.
• Energy requirements are related
to animal size, activity, and
environment.
Illustrative Examples:
• Cellular structural similarities across animal kingdom
• Methods of cellular control and regulation (e.g. hormones)
• Methods of cellular transport (e.g. diffusion, active transport)
• Temperature regulation in animals (e.g. negative feedback)
• Onset of labor in childbirth (e.g. positive feedback)
• Competition for resources, territoriality, health, predation,
accumulation of wastes  population controls (e.g. natural
selection)
Mix & Match Review: Ch. 40.4
1. Explain the relationship
between: size and
metabolic rate
1, 4, 7
1. Explain the relationship
between: activity and
metabolic rate
2, 5, 8
3, 6
1. Compare (2) and
contrast (2) torpor with
hibernation
Key Point: Energy requirements are related to animal
size, activity, and environment.
• Bioenergetics is the overall flow and
transformation of energy in an animal
• It determines how much food an animal needs
and it relates to an animal’s size, activity, and
environment
© 2011 Pearson Education, Inc.
Bioenergetics
Gross consumption (input)
-biosynthesis (output)
= Surplus energy
Figure 40.17
Quantifying Energy Use
• Metabolic rate is the amount of energy an
animal uses in a unit of time
• Metabolic rate can be determined by
– An animal’s heat loss
– The amount of oxygen consumed or carbon
dioxide produced
© 2011 Pearson Education, Inc.
AP Lab #5
Influences on Metabolic Rate
• Metabolic rates are affected by many factors
besides whether an animal is an endotherm or
ectotherm
• Two of these factors are size and activity level
© 2011 Pearson Education, Inc.
Figure 40.19a
Figure 40.19b
Energy Budgets
• Different species use energy and materials in
food in different ways, depending on their
environment
• Use of energy is partitioned to BMR (or SMR),
activity, thermoregulation, growth, and
reproduction
© 2011 Pearson Education, Inc.
Figure 40.20
Figure 40.20a
Figure 40.20b
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
© 2011 Pearson Education, Inc.
“Hay! Here are the key points…”
• Animal form and function are
correlated at all levels of
organization.
• Feedback control maintains the
internal environment in many
animals.
• Homeostatic processes for
thermoregulation involve form,
function, and behavior.
• Energy requirements are related to
animal size, activity, and
environment.
Practice Quiz Questions (Campbell)
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#1
#2
#3
#4
#5
#10