+ Chapter 40:
Basic
Principles of
Form and
Function
Mrs. Valdes
AP Biology
Overview:
Diverse Forms, Common
+
Challenges
 Anatomy:
study of
biological form of
organism
 Physiology: study
of
biological functions
organism performs
 Comparative
study of
animals reveals form and
function closely
correlated… you know
this!
Concept 40.1: Animal form and function
+ correlated at ALL levels of organization


Body plans evolved and determined by genome
Physical Constraint: ability to perform certain actions
depends on animal’s shape, size, and environment
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Environment Exchange: animal’s size and shape
directly affect how it exchanges energy and
materials with its surroundings


Evolutionary convergence reflects different species’
adaptations to similar environmental challenge
Physical laws impose constraints on animal size and
shape
occurs as substances dissolved in aqueous medium
diffuse and are transported across cells’ plasma
membranes
 Single-celled: protist living in water has sufficient
surface area of plasma membrane to service its entire
volume of cytoplasm
 Multicellular organisms: some have sac body plan;
body walls only two cells thick, facilitating diffusion of
materials
 More complex organisms: highly folded internal
surfaces for exchanging materials
 Vertebrates: space between cells filled with interstitial
fluid
 allows for movement of material into and out of cells
A complex body plan helps animal in variable
environment to maintain stable internal environment
Hierarchical Organization of Body Plans
+
 Cells > Tissues > Organs > Organ System
 Tissues
classified into four main categories: epithelial,
connective, muscle, and nervous
Epithelial Tissue
+
 Epithelial tissue: covers outside of body and lines organs
and cavities within body
 contains cells closely joined
 shape of epithelial cells:
 cuboidal (like dice)
 columnar (like bricks on end)
 squamous (like floor tiles)
 arrangement of epithelial cells:
 simple (single cell layer)
 stratified (multiple tiers of cells)
 pseudostratified (a single
layer of cells of varying length)
Connective Tissue
+
 mainly binds and supports
other tissues
 contains sparsely packed
cells scattered through
extracellular matrix
 matrix consists of fibers in
liquid, jellylike, or solid foundation
 Types of connective tissue fiber:

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Connective cells:


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Collagenous fibers provide strength and flexibility
Elastic fibers stretch and snap back to original length
Reticular fibers join connective tissue to adjacent tissues
Fibroblasts: secrete the protein of extracellular fibers
Macrophages: involved in immune system
Fibers and foundation combine to form six major types of connective
tissue:
Loose connective tissue: binds epithelia to underlying tissues; holds organs in place
Cartilage: strong and flexible support material
Fibrous connective tissue: found in tendons (attach muscles to bones) and ligaments (connect bones at
joints)
Adipose tissue: stores fat for insulation and fuel
Blood: composed of blood cells and cell fragments in blood plasma
Bone: mineralized and forms skeleton
Fig. 40-5c
+
Connective Tissue
Loose
connective
tissue
Chondrocytes
Cartilage
Elastic fiber
Chondroitin
sulfate
Nuclei
Fat droplets
Adipose
tissue
Osteon
150 µm
Fibrous
connective
tissue
30 µm
100 µm
120 µm
Collagenous fiber
White blood cells
Blood
55 µm
700 µm
Bone
Central canal
Plasma
Red blood
cells
Fig. 40-5d
+
120 µm
Collagenous fiber
Elastic fiber
Loose connective tissue
Fig. 40-5e
+
30 µm
Nuclei
Fibrous connective tissue
Fig. 40-5f
+
700 µm
Osteon
Central canal
Bone
Fig. 40-5g
+
100 µm
Chondrocytes
Chondroitin
sulfate
Cartilage
Fig. 40-5h
+
150 µm
Fat droplets
Adipose tissue
Fig. 40-5i
+
55 µm
White blood cells
Plasma
Blood
Red blood
cells
+ Muscle Tissue
 consists
of long cells called muscle fibers,
which contract in response to nerve signals
 Types:

Skeletal muscle: or striated muscle, responsible for voluntary movement

Smooth muscle: responsible for involuntary body activities

Cardiac muscle: responsible for contraction of the heart
Fig. 40-5j
+
Muscle Tissue
Multiple
nuclei
Muscle fiber
Sarcomere
Skeletal
muscle
Nucleus
100 µm
Intercalated
disk
50 µm
Cardiac muscle
Nucleus
Smooth
muscle
Muscle
fibers
25 µm
Fig. 40-5k
+
Multiple
nuclei
Muscle fiber
Sarcomere
100 µm
Skeletal muscle
Fig. 40-5l
+
Nucleus
Muscle
fibers
25 µm
Smooth muscle
Fig. 40-5m
+
Nucleus
Intercalated
disk
Cardiac muscle
50 µm
+Nervous Tissue
 senses
stimuli and transmits signals
throughout the animal
 Contains:

Neurons: nerve cells, that transmit nerve impulses

Glial cells, or glia: help nourish, insulate, and replenish neurons
Coordination and Control
+
 Depend on endocrine system
and nervous system
 Endocrine system: transmits
hormones to receptive cells
throughout body via blood
 hormone
may affect one or more
regions throughout body
 Hormones relatively slow acting,
but can have long-lasting effects
 Nervous
system: transmits
information between specific
locations
 information
conveyed depends on
a signal’s pathway NOT type of
signal
 Nerve signal transmission is FAST
 Nerve impulses received by
neurons, muscle cells, and
endocrine cells
+Concept 40.2: Feedback control loops maintain
internal environment in many animals
 Animals
manage internal environment by
regulating or conforming to external
environment
 Regulator: uses
internal control
mechanisms to
moderate internal
change
in face of external,
environmental
fluctuation
 Conformer: allows
internal condition
to vary with certain
external changes
Homeostasis
+
Maintain “steady state” or internal balance regardless of external environment

Humans: body temperature, blood pH, and glucose concentration

Mechanisms: moderate changes in internal environment

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For given variable, fluctuations above/below
set point serve as stimulus that are detected by
sensor and trigger response

response returns the variable to the set point
Feedback Loops:
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Negative feedback

Helps return variable to either normal range
or a set point

Most homeostatic control systems function by
negative feedback, where buildup of the end
product shuts the system off
Positive feedback

occur in animals, but do not usually contribute
to homeostasis

Set points and normal ranges change with age or
show cyclic variation

Acclimatization: homeostasis can adjust to changes in external environment
Concept 40.3: Homeostatic processes for
+
thermoregulation
involve form, function, & behavior
Thermoregulation: process by
which animals maintain internal
temperature within tolerable range
 Endotherm: animal generates heat
by metabolism; Ex: birds and
mammals
 active at a greater range of
external temperatures
 more energetically expensive

Homeotherm: body temperature
relatively constant
 Ectotherm: animal gains heat from
external sources; include most
invertebrates, fishes, amphibians,
and non-avian reptiles
 tolerate greater variation in
internal temperature, while
endotherms are
 Poikilotherm: body temperature
varies with its environment,

+
Balancing Heat Loss & Gain
Organisms exchange heat by :
•
•
•
•
•
conduction
convection
radiation
evaporation
Heat regulation in mammals
involves integumentary
system:
•
•
•
•
skin
hair
nails
General adaptations:
•
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Insulation
Circulatory adaptations
Cooling by evaporative heat loss
Behavioral responses
Adjusting metabolic heat production
+ Insulation
 Major
thermoregulatory adaptation in mammals
and birds
 Ex: Skin, feathers, fur, and blubber
 Reduce heat flow between an animal and its
environment
Circulatory Adaptations
+
 Regulation
of blood flow near body
surface significantly affects
thermoregulation
 Many endotherms and some
ectotherms alter amount of blood
flowing between body core and skin
 Vasodilation: blood flow in skin
increases increase heat loss
 Vasoconstriction: blood flow in skin
decreases decrease heat loss
 Countercurrent exchange:
important mechanism for reducing
heat loss; transfer heat between fluids
flowing in opposite directions
 arrangement of blood vessels in
marine mammals and birds
 Some bony fishes and sharks
 Many endothermic insects use to
maintain high temperature in thorax
+ Cooling by Evaporative Heat Loss
 Animals
lose heat through evaporation of
water in sweat
 Panting increases cooling effect in birds and
many mammals
 Sweating/bathing moistens skin, helping cool
animal down
+Behavioral Responses
 Endotherms
and
ectotherms use
behavioral responses to
control body
temperature
 Terrestrial
invertebrates
have postures to
minimize or maximize
absorption of solar heat
 Ex: Dragonfly
obelisk to
minimize sun exposure
Adjusting Metabolic Heat Production
+
 Some
animals regulate
body temperature by
adjusting rate of
metabolic heat
production
 Heat
production
increased by muscle
activity like moving or
shivering
 Some
ectotherms
shiver to increase
body temperature
Acclimatization in Thermoregulation
+
 Birds and mammals vary
insulation to acclimatize
to seasonal temperature
changes
 Temps subzero: some
ectotherms produce
“antifreeze” compounds
to prevent ice formation
in their cells
 Thermoregulation:
controlled by
hypothalamus
 Hypothalamus:
triggers
heat loss or heat
generating mechanisms
 Fever: result
of change
to set point for
biological thermostat
Concept
40.4: Energy requirements related
+
to animal size, activity, and environment
Bioenergetics: overall flow and
transformation of energy in an
animal
 determines how much food
animal needs
 relates to animal’s size, activity,
and environment
 Energy Allocation and Use
 Animals harvest chemical energy
from food
 Food  ATP  Cellular Work
 After needs of staying alive
met, remaining food molecules
used in biosynthesis
 Biosynthesis: includes
 body growth and repair
 synthesis of storage material
such as fat
 production of gametes

Quantifying Energy Use
+
 Metabolic rate: amount of
energy animal uses in unit of time
 One way to measure: determine
amount of oxygen consumed OR
carbon dioxide produced
 affected by many factors besides
whether an animal is an
endotherm or ectotherm
 size
 activity
 Basal metabolic rate (BMR):
metabolic rate of endotherm at
rest at “comfortable” temperature
 Standard metabolic rate (SMR):
metabolic rate of ectotherm at
rest at specific temperature
 Both rates assume nongrowing,
fasting, and nonstressed animal
 Ectotherms have lower metabolic
rates than endotherms of
comparable size
+ Size and Metabolic
Rate
 Metabolic
rate per gram
inversely related to body
size among similar
animals
 Higher
metabolic rate of
smaller animals higher
oxygen delivery rate,
breathing rate, heart rate,
and greater (relative)
blood volume, compared
with a larger animal
+Activity and Metabolic Rate
 Maximum
metabolic rate
animal can sustain
inversely related to
duration of the
activity
+Energy Budgets
 Different
species use energy and materials in
different ways depending on environment
 Use
of energy is partitioned to BMR (or SMR),
activity, thermoregulation, growth, and
reproduction
+Torpor and Energy Conservation
 Torpor: physiological
state
in which activity is low and
metabolism decreases
 enables animals to save
energy while avoiding
difficult and dangerous
conditions
 Hibernation: long-term
torpor; adaptation to winter
cold and food scarcity
 Estivation: summer torpor;
enables animals to survive
long periods of high
temperatures and scarce
water supplies
 Daily torpor: exhibited by
many small mammals and
birds; seems adapted to
feeding patterns
+ You should now be able to:
1.
2.
3.
4.
5.
6.
7.
Distinguish among the following sets of terms:
collagenous, elastic, and reticular fibers; regulator and
conformer; positive and negative feedback; basal and
standard metabolic rates; torpor, hibernation, estivation,
and daily torpor
Relate structure with function and identify diagrams of the
following animal tissues: epithelial, connective tissue (six
types), muscle tissue (three types), and nervous tissue
Compare and contrast the nervous and endocrine systems
Define thermoregulation and explain how endotherms
and ectotherms manage their heat budgets
Describe how a countercurrent heat exchanger may
function to retain heat within an animal body
Define bioenergetics and biosynthesis
Define metabolic rate and explain how it can be
determined for animals