Download Chapter 40: Animal Form and Function

CHAPTER 40:
ANIMAL FORM
AND FUNCTION
Essential Knowledge




2.a.1 – All living systems require constant input of
free energy.
2.c.1 – Organisms use feedback mechanisms to
maintain their internal environments and respond to
external environmental changes.
2.c.2 – Organisms respond to changes in their
external environments.
4.b.2 – Cooperative interaction within organisms
promote efficiency in the use of energy and matter.
Introduction

Anatomy –
 The

study of structure of organism
Physiology –
 The
study of the functions of an organism’s
anatomical features

Bioenergetics –
 How
organisms obtain, process and use their
energy resources
Constraints

Limits to animal shape and size  1)
Physical laws
 Physics
of flight
 Gravity
 Laws of hydrodynamics
 2)
Environment
 Aqueous
requirement for cellular medium
 Plasma
 Hierarchy
membrane, surface area to volume ratios
of living organisms
 Climate/Weather
Organizational Levels

Illustrate emergent properties
 Cell
– Basic unit of life
 Tissue – Group of cells with same function
 Organ – Group of tissues with same function
 Organ system – Group of organs with same function
 Individual – All organ systems working together
Tissue

Four Major Types:


Epithelial, muscle, connective, nervous
Epithelial
 Tightly
packed cells (very little space in b/t)
 Cover outside of body
 Line organs and cavities
 Function: barrier against injury, microbes and fluid loss
 Classified by: # of layers, shape
#
of layers – simple and stratified
 Shape – cuboidal, columnar, squamous
Tissue, cont.

Connective
 Function:
bind and support other tissue types
 NOT tightly packed
 Three kinds of protein fibers:
 Collagenous
 Elastic
 Reticular
 Major
types of connective tissue:
 Loose,
blood
adipose, fibrous, cartilage, bone and
Tissue, cont.

Muscle
 Long
cells capable of contracting
 Consumes
most of cellular energy work
 Stimulated
by nerve cells
 Made of proteins called actin and myosin
 Most abundant tissue in animals
 Three types:
 Skeletal,
cardiac, smooth
Tissue, cont.

Nervous
Sense
stimuli and transmits signals
Functional unit:
Nerve
cell (neuron)
Specialized to transmit nerve impulses
Concentrated
Remember?
in brain (anterior end)
Called cephalization
Organs and organ systems

Systems:
 Digestive
 Circulatory
 Respiratory
 Immune/lymphatic
 Excretory
 Endocrine
 Reproductive
 Nervous
 Integumentary
 Skeletal
 Muscular
Energy

Two ways to obtain energy:
 Heterotroph
 Autotroph

Bioenergetics:
 The
flow of energy through an animal
 Limits animal’s behavior, growth, repair,
regulation and reproduction
 Determines how much food an animal must
consume
Energy sources

Animals are heterotrophs
 Obtain energy through enzymatic
hydrolysis (aka – Cellular Rs)
 Use
food, oxygen to make energy molecules
and carbon dioxide (waste product)
 Most
of energy molecules are made into
ATP
 Production
and use of ATP generates heat
 Animal continuously gives off heat
 This
release of heat helps to regulate internal
body temp
Metabolic rate
Def – amount of energy animal uses in a
given amount of time
 Measured in calories (C)
 Can be determined:

 Monitoring
an animal’s rate of heat loss using a
calorimeter
 Measuring oxygen consumption
 Can
use an EKG or heart monitor to measure
 Measuring
carbon dioxide output
Influences on Metabolic Rate

1) Size
 Amt
of energy to maintain each gram of weight is
inversely related to size
 Small animals = MORE energy per gram of weight

2) Activity
 More

activity = more energy needed
3) Others
 Size,
sex, age, body/environmental temps
Homeostasis

Def - How an animal maintains stable
internal environmental conditions
 Such
as: temp, heart rate, metabolism
“Steady state”
 Two schools/groups of animals:

 Regulators
 Conformers
Regulators and Conformers

Regulators – use internal control mechanisms to
moderate internal changes (despite external
fluctuations)
 Ex:

Conformers –allow their internal environment to
vary with external fluctuations
 Ex:

freshwater and saltwater fish
lizards
No organism is SOLELY one or another
 Animals
maintain homeostasis while being BOTH a
regulator AND conformer
Homestatic mechanisms

Three functional control mechanisms:
 1)
Receptor
 Detects
 2)
change
Control center/Integrator
 Processes
change and sends response to
effector
 3)
Effector
 Changes
 Ex:
internal conditions
a house thermostat
Positive and Negative Feedback

Positive and Negative Feedback Loops
Thermoregulation
Def - The process by which animals
maintain an internal body temperature
 Most biological body processes are VERY
sensitive to changes in body temp
 Two strategies:

 Endotherm
 Ectotherm
Endotherm
Animals that internally control body temp
 Ex:

 Mammals,
birds, few reptiles, some fish, most insect
species
High metabolic rate
 Maintain high and very stable internal temp

 Ex:

Humans – 98.6o F
Source of heat: metabolic heat (ATP)
Endotherm, cont.

Advantages:
 Can
perform rigorous activities for longer periods
of time
 Elaborate circulatory systems (division of blood)
 Elaborate respiratory system (oxygen exchange)
 Maintain stable body temp

Disadvantages:
 Very
“expensive” in energy use
 High metabolic rate
 Need
to consume much more food than ectotherm
Ecototherm
Animals who gain most of heat from
environment
 Ex:

 Reptiles,
amphibians, most invertebrates, fishes
Low metabolic rate
 Regulate body temp by behavioral
mechanisms

 Hibernation
 Basking
in sun
 Shade seeking
Modes of Heat Exchange
Ectotherms and endotherms exchange
heat using the same processes
 Four processes to do so:

 Radiation
 Evaporation
 Convection
 Conduction
Balance of Heat Exchange

Ultimate goal:
To
balance heat loss with heat gain
Five adaptations help animals to meet
this goal:
1)
Insulation
2) Circulatory Adaptations
3) Cooling by Evaporative Heat Loss
4) Behavioral Responses
5) Adjusting Metabolic Heat Production
Energy Conservation

Animals often times encounter periods of
time that challenge their heat balancing
abilities
 Ex:

extreme temps; food is scarce
Torpor – a physiological state in which
animal activity is low and metabolism
decreases
 Enables
animals to save energy while
avoiding dangerous conditions
Energy Conservation, cont.

Hibernation:
 Long-term
Other animals
hibernating
torpor
 Adaptation to winter temp and lack of food
 Vertebrate endotherms hibernate
 Body temps decline
 Saves energy and metabolic rate drops
 Triggered by shorter days (less daylight) and slight
temperature decreases
 Ex: bears, ground squirrels
Bear Hibernating (1:00)
Energy Conservation, cont.

Estivation:
 Summer
torpor
 Adaptation to long periods of high temps
and scarce water supply
 Slow metabolism and inactivity
 Triggered by long days
 Ex: frogs, snails, salamanders