Transcript video slide - Dublin City Schools

Chapter 40: Basic
Principles of Animal
Form and Function
40.1 Form and Function
• 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
• Many different animal body plans have evolved
and are determined by the genome
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-2
The ability to perform
certain actions depends
on an animal’s shape,
size, and environment
(a) Tuna
(b) Penguin
Physical laws impose
constraints on animal
size and shape
(c) Seal
• Exchange occurs as substances dissolved in
the aqueous medium diffuse and are
transported across the cells’ plasma
membranes
• A single-celled protist living in water has a
sufficient surface area of plasma membrane to
service its entire volume of cytoplasm
Video: Hydra Eating Daphnia
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-3
An animal’s size and
shape directly affect how it
exchanges energy and
materials with its
surroundings
Exchange
Mouth
Gastrovascular
cavity
Exchange
Exchange
0.15 mm
Exchange with the Environment1.5 mm
(a) Single cell
(b) Two layers of cells
Fig. 40-4
0.5 cm
External environment
CO2
Food
O2
Mouth
Animal
body
Respiratory
system
50 µm
More complex
organisms have
highly folded
internal surfaces
for exchanging
materials
Lung tissue
Nutrients
Heart
Cells
Circulatory
system
10 µm
Interstitial
fluid
Digestive
system
Excretory
system
Lining of small intestine
Kidney tubules
Anus
Unabsorbed
matter (feces)
Metabolic waste products
(nitrogenous waste)
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
• 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 in a variable
environment to maintain a relatively stable internal
environment
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
I. Animal Tissues
A. Epithelial tissue: provides outer covering of
the body and lines the organs and cavities
within the body
1. Bottom layer attaches to the noncellular
basement
2. types are classified by shape and layers
3. Some specialized to absorb/secrete. Some
have cilia.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-5a
Epithelial Tissue
Cuboidal
epithelium
Simple
columnar
epithelium
Pseudostratified
ciliated
columnar
epithelium
Stratified
squamous
epithelium
Simple
squamous
epithelium
Fig. 40-5b
Apical surface
Basal surface
Basal lamina
40 µm
Fig. 40-5c
B. Connective Tissue : live cells are scattered in a nonliving matrix
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
Collagenous fiber
1. Loose connective
tissue: binds epithelia to
other tissues, holds
organs in place.
120 µm
a. Collagen fibers: strong
(skin)
b. Elastic fibers: retractable
property
c. Reticular fibers: join
Elastic fiber
connective tissue to
adjacent tissues (lattice) Loose connective tissue
Fig. 40-5h
2. Adipose tissue stores fat for insulation and
fuel
150 µm
Fat droplets
Adipose tissue
Fig. 40-5e
3. Fibrous connective tissue:
dense collagen fibers
a. tendons: muscles to
bones (little flexibility)
b. ligaments: bone to
bones at joints (more
flexible)
30 µm
Nuclei
Fibrous connective tissue
Fig. 40-5g
4. Cartilage is a strong and
flexible support material
(chondrocytes embedded
in chondrin and collagen
fibers)
100 µm
Chondrocytes
Chondroitin
sulfate
Cartilage
Fig. 40-5f
5. Bone: osteocytes embedded in collagen and
mineral deposits: Haversian systems
700 µm
Osteon
Central canal
Bone
Fig. 40-5i
6. Blood is composed of blood cells and cell
fragments in blood plasma
55 µm
White blood cells
Plasma
Blood
Red blood
cells
Fig. 40-5j
C. Muscle Tissue: long cells capable of contraction
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
1. Skeletal (striated) muscle: voluntary movement
Fig. 40-5m
Nucleus
Intercalated
disk
50 µm
2. Cardiac muscle: branched striated muscle of the heart
Fig. 40-5l
Nucleus
Muscle
fibers
25 µm
3. Smooth muscle: slower, involuntary movement
D. Nervous Tissue
• Nervous tissue senses stimuli and transmits
signals throughout the animal
• Nervous tissue contains:
– Neurons, or nerve cells, that transmit nerve
impulses
– Glial cells, or glia, that help nourish, insulate,
and replenish neurons
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-5n
Nervous Tissue
40 µm
Dendrites
Cell body
Glial cells
Axon
Neuron
Axons
Blood vessel
15 µm
40.2 Coordination and Control: 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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Coordination and Control
• The nervous system
transmits information
between specific
locations (depends on a
signal’s pathway)
• Nerve signal
transmission is very fast
• Nerve impulses can be
received by neurons,
muscle cells, and
endocrine cells
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Homeostasis
• Animals manage their internal environment by
regulating or conforming to the external environment
• 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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Mechanisms of Homeostasis (think thermostat)
• 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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Feedback Loops in Homeostasis
• Negative feedback- a change triggers a
control mechanism that counteracts the effect
of the change (ex. body temperature)
– Most homeostatic control systems function by
negative feedback, where buildup of the end
product shuts the system off
• Positive feedback-a change triggers a
mechanism that amplifies the response (ex.
childbirth)
– do not usually contribute to homeostasis
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
40.3 Example of Homeostasis:
• Thermoregulation is the process by which
animals maintain an internal temperature within
a tolerable range
– 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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• 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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-10
Radiation
Evaporation
Balancing Heat Loss
and Gain
Convection
Conduction
Five general adaptations help animals
thermoregulate:
1. Insulation
2. Circulatory adaptations:
•
arrangement of blood vessels in many marine
mammals and birds allows for countercurrent
exchange. Transfer heat between fluids flowing in
opposite directions
3. Cooling by evaporative heat loss
4. Behavioral responses
5. Adjusting metabolic heat production
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-12
Canada goose
Bottlenose
dolphin
Blood flow
Artery Vein
Vein
Artery
35ºC
33º
30º
27º
20º
18º
10º
9º
Fig. 40-16
Sweat glands secrete
sweat, which evaporates,
cooling the body.
Body temperature
decreases;
thermostat
shuts off cooling
mechanisms.
Thermostat in hypothalamus
activates cooling mechanisms.
Blood vessels
in skin dilate:
capillaries fill;
heat radiates
from skin.
Increased body
temperature
Homeostasis:
Internal temperature
of 36–38°C
Body temperature
increases; thermostat
shuts off warming
mechanisms.
Decreased body
temperature
Blood vessels in skin
constrict, reducing
heat loss.
Skeletal muscles contract;
shivering generates heat.
Thermostat in
hypothalamus
activates warming
mechanisms.
40.4 Bioenergetics: The study of how organisms
manage their resources
• It determines
how much food
an animal
needs and
relates to an
animal’s size,
activity, and
environment
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Quantifying Energy Use
• Metabolic rate is the amount of energy an
animal uses in a unit of time
• Energy is measured in calories (cal) or
kilocalories (Kcal = 1000 calories)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Measuring Metabolic Rate
1. Measure heat loss per unit of time (ex.
placing a bird in a calorimeter)
2. Determine the amount of oxygen consumed
by cellular respiration
– Minimal rate: necessary to support basic
functions (breathing, heart rate)
– Maximal rate: occurs during peak activity
(sprinting, high level aerobics)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Influences on Metabolic Rate
• Metabolic rates are affected by many factors
besides whether an animal is an endotherm or
ectotherm
• These factors are:
Age
body temperature
surrounding temperature
amount of available O2
Hormone balance
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
gender
time of day
food intake
Rate Types: Both rates assume a nongrowing, fasting, and
nonstressed animal
• Basal metabolic rate (BMR) is the metabolic rate
of an endotherm at rest at a “comfortable”
temperature
– Human avg.: 1600-1880 Kcal/day: adult male
1300-1500 Kcal/day: adult female
• Standard metabolic rate (SMR) is the metabolic
rate of an ectotherm at rest at a specific
temperature
Size and Metabolic Rate
• Metabolic rate per gram of body weight is
inversely related to body size among similar
animals
– may be due to surface area to volume ratio but does
not explain the relationship in ectotherms
• The higher metabolic rate of smaller animals leads to
a higher oxygen delivery rate, breathing rate, heart
rate, and greater (relative) blood volume, compared
with a larger animal
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-19a
103
BMR (L O2/hr) (log scale)
Elephant
Horse
102
Human
Sheep
10
Cat
Dog
1
10–1
Rat
Ground squirrel
Shrew
Mouse
Harvest mouse
10–2
10–3
10–2
102
1
10–1
10
Body mass (kg) (log scale)
(a) Relationship of BMR to body size
103
Fig. 40-19b
8
7
BMR (L O2/hr) (per kg)
Each gram of a mouse
requires about 20X’s
more calories as a gram
of an elephant
Shrew
6
5
4
Harvest mouse
3
Mouse
2
Rat
1
Ground squirrel
0
10–3
10–2
Sheep
Human Elephant
Cat
Dog
Horse
1
10
102
10–1
Body mass (kg) (log scale)
103
(b) Relationship of BMR per kilogram of body mass to body size
Annual energy expenditure (kcal/hr)
Fig. 40-20a
Reproduction
800,000
Thermoregulation
Basal
(standard)
metabolism
Growth
Activity
60-kg female human
from temperate climate
Annual energy expenditure (kcal/yr)
Fig. 40-20b
Basal
(standard)
metabolism
Reproduction
Thermoregulation
Activity
340,000
4-kg male Adélie penguin
from Antarctica (brooding)
Annual energy expenditure (kcal/yr)
Fig. 40-20c
Basal
(standard)
metabolism
Reproduction
Thermoregulation
Activity
4,000
0.025-kg female deer mouse
from temperate
North America
Annual energy expenditure (kcal/yr)
Fig. 40-20d
Basal
(standard)
metabolism
Reproduction
Growth
Activity
8,000
4-kg female eastern
indigo snake
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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings