Download Chapter 47: Effectors: Making Animals Move

Chapter 47: Effectors: Making Animals Move
CHAPTER 47
Effectors: Making
Animals Move
Chapter 47: Effectors: Making Animals Move
Chapter 47: Effectors:
Making Animals Move
Effectors
Cilia, Flagella, and Cell Movement
Muscle Contraction
Skeletal Systems Provide Support for Muscles
Other Effectors
Chapter 47: Effectors: Making Animals Move
Effectors
• Effectors enable animals to respond to
information from their internal and external
environments.
• Most effector mechanisms generate
mechanical forces and cause movement.
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Chapter 47: Effectors: Making Animals Move
Cilia, Flagella, and Cell
Movement
• Cell movement is generated by two
structures, microtubules and microfilaments.
• Both consist of long protein molecules that
can change length or shape.
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Chapter 47: Effectors: Making Animals Move
Cilia, Flagella, and Cell
Movement
• The movements of cilia and flagella depend
on microtubules.
Review Figures 47.1, 47.3, 47.4
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Chapter 47: Effectors: Making Animals Move
Figure
47.1
Figure 47.1
figure 47-01.jpg
Chapter 47: Effectors: Making Animals Move
Figur
e
47.3
Figure 47.3
figure 47-03.jpg
Chapter 47: Effectors: Making Animals Move
Figure 47.4
Figure 47.4
figure 47-04.jpg
Chapter 47: Effectors: Making Animals Move
Cilia, Flagella, and Cell
Movement
• Microfilaments allow animal cells to change
their shape and move.
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Chapter 47: Effectors: Making Animals Move
Muscle Contraction
• The three types of vertebrate muscle are
smooth, cardiac, and skeletal.
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Chapter 47: Effectors: Making Animals Move
Muscle Contraction
• Smooth muscle provides contractile force for
internal organs.
• Smooth muscle cells are electrically coupled
through gap junctions, so action potentials
causing contraction spread rapidly
throughout the tissue.
• Autonomic neurotransmitters alter the
membrane potential of smooth muscle cells.
Review Figure 47.6
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Chapter 47: Effectors: Making Animals Move
Figure
47.6 –
Part 1
Figure 47.6 – Part 1
figure 47-06a.jpg
Chapter 47: Effectors: Making Animals Move
Figure 47.6
– Part 2
Figure 47.6 – Part 2
figure 47-06b.jpg
Chapter 47: Effectors: Making Animals Move
Muscle Contraction
• The walls of the heart consist of sheets of
branching cardiac muscle cells.
• The cells are electrically coupled through
gap junctions, so action potentials spread
rapidly throughout sheets of cardiac muscle
and cause coordinated contractions.
• Some are pacemaker cells that generate
heartbeat
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Chapter 47: Effectors: Making Animals Move
Muscle Contraction
• Skeletal, or striated, muscle consists of
muscle fiber bundles.
• Each muscle fiber is a huge cell containing
multiple nuclei and numerous myofibrils,
which are bundles of actin and myosin
filaments.
• The regular, overlapping arrangement of the
filaments into sarcomeres gives the muscle
a striated appearance.
• During contraction, filaments slide past each
other in a telescoping fashion.
Review Figure 47.7
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Chapter 47: Effectors: Making Animals Move
Figure 47.7
– Part 1
Figure 47.7 – Part 1
figure 47-07a.jpg
Chapter 47: Effectors: Making Animals Move
Figure 47.7
– Part 2
Figure 47.7 – Part 2
figure 47-07b.jpg
Chapter 47: Effectors: Making Animals Move
Muscle Contraction
• The molecular mechanism of muscle
contraction involves binding of the globular
heads of myosin molecules to actin.
• Upon binding, the myosin head changes
conformation, causing the two filaments to
move relative to each other.
• Release of the myosin heads from actin and
return to original conformation requires ATP.
Review Figure 47.8
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Chapter 47: Effectors: Making Animals Move
Figure
47.8
Figure 47.8
figure 47-08.jpg
Chapter 47: Effectors: Making Animals Move
Muscle Contraction
• The plasma membrane of the muscle fiber is
continuous with a system of T tubules that
extends deep into the sarcoplasm.
Review Figure 47.9
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Chapter 47: Effectors: Making Animals Move
Figure
47.9
Figure 47.9
figure 47-09.jpg
Chapter 47: Effectors: Making Animals Move
Muscle Contraction
• When an action potential spreads across the
plasma membrane and through the T tubules, it
causes Ca2+ ions to be released from the
sarcoplasmic reticulum.
• Ca2+ ions bind to troponin and change its
conformation, pulling the tropomyosin strands away
from the myosin binding sites on the actin filament.
• Cycles of actin–myosin binding and release occur,
and the muscle fiber contracts until Ca2+ is returned
to the sarcoplasmic reticulum.
Review Figure 47.10
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Chapter 47: Effectors: Making Animals Move
Figure
47.10
Figure 47.10
figure 47-10.jpg
Chapter 47: Effectors: Making Animals Move
Muscle Contraction
• In striated muscle, a single action potential
causes a minimum unit of contraction, a
twitch.
• Twitches occurring in rapid succession can
be summed, increasing the strength of
contraction.
Review Figure 47.11
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Chapter 47: Effectors: Making Animals Move
Figure
47.11
Figure 47.11
figure 47-11.jpg
Chapter 47: Effectors: Making Animals Move
Muscle Contraction
• Slow-twitch muscle fibers are adapted for
extended, aerobic work; fast-twitch fibers
for generating maximum forces for short
periods.
• The ratio of slow- to fast-twitch fibers in an
individual’s muscle is genetically
determined.
Review Figure 47.12
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Chapter 47: Effectors: Making Animals Move
figure 47-12.jpg
Figure
47.12
Figure 47.12
Chapter 47: Effectors: Making Animals Move
Skeletal Systems Provide
Support for Muscles
• Skeletal systems provide rigid supports
against which muscles can pull.
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Chapter 47: Effectors: Making Animals Move
Skeletal Systems Provide
Support for Muscles
• Hydrostatic skeletons are fluid-filled cavities
that can be squeezed by muscles.
Review Figure 47.13
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Chapter 47: Effectors: Making Animals Move
Figure 47.13
– Part 1
Figure 47.13 – Part 1
figure 47-13a.jpg
Chapter 47: Effectors: Making Animals Move
Figure 47.13 –
Part 2
Figure 47.13 – Part 2
figure 47-13b.jpg
Chapter 47: Effectors: Making Animals Move
Skeletal Systems Provide
Support for Muscles
• Exoskeletons are hardened outer surfaces
to which internal muscles are attached.
Review Figure 47.14
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Chapter 47: Effectors: Making Animals Move
Figure
47.14
Figure 47.14
figure 47-14.jpg
Chapter 47: Effectors: Making Animals Move
Skeletal Systems Provide
Support for Muscles
• Endoskeletons are internal, articulated
systems
• They are composed of rigid rod, plate, and
tubelike supports
• These consisting of bone and cartilage to
which muscles are attached.
Review Figure 47.15
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Chapter 47: Effectors: Making Animals Move
Figure
47.15
Figure 47.15
figure 47-15.jpg
Chapter 47: Effectors: Making Animals Move
Skeletal Systems Provide
Support for Muscles
• Bone is continually being remodeled by
osteoblasts, which lay down new bone, and
osteoclasts, which erode bone.
Review Figure 47.16
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Chapter 47: Effectors: Making Animals Move
Figure
47.16
Figure 47.16
figure 47-16.jpg
Chapter 47: Effectors: Making Animals Move
Skeletal Systems Provide
Support for Muscles
• Bones develop from connective tissue
membranes or from cartilage through
ossification.
• Cartilage bone can grow until centers of
ossification meet.
Review Figure 47.17
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Chapter 47: Effectors: Making Animals Move
Figure
47.17
Figure 47.17
figure 47-17.jpg
Chapter 47: Effectors: Making Animals Move
Skeletal Systems Provide
Support for Muscles
• Bone can be solid and hard, or it can
contain numerous internal spaces.
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Chapter 47: Effectors: Making Animals Move
Skeletal Systems Provide
Support for Muscles
• Tendons connect muscles to bones.
• Ligaments connect bones to each other and
help direct forces generated by muscles by
holding tendons in place.
Review Figure
47.19
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Chapter 47: Effectors: Making Animals Move
Figure
47.19
Figure 47.19
figure 47-19.jpg
Chapter 47: Effectors: Making Animals Move
Skeletal Systems Provide
Support for Muscles
• Muscles and bones work together around
joints as systems of levers.
Review Figures 47.20, 47.21
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Chapter 47: Effectors: Making Animals Move
Figure
47.20
Figure 47.20
figure 47-20.jpg
Chapter 47: Effectors: Making Animals Move
Figure
47.21
Figure 47.21
figure 47-21.jpg
Chapter 47: Effectors: Making Animals Move
Other Effectors
• Effector organs other than muscles
nematocysts
 chromatophores
 glands
 electric pulses

Review Figure 47.22
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