chapter 30 introduction how animals...

© 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko

PowerPoint Lectures for

Campbell Biology: Concepts & Connections, Seventh Edition

Reece, Taylor, Simon, and Dickey

Chapter 30Chapter 30 How Animals MoveIntroduction

Horses are well adapted for long-distance runningwith legs that are

– long and

– light.

© 2012 Parson Education, Inc.

Figure 30.0_1Chapter 30: Big Ideas

Movement andLocomotion

The Vertebrate Skeleton

Muscle Contractionand Movement

Figure 30.0_2

MOVEMENT ANDLOCOMOTION


Animal movement

– is very diverse but

– relies on the same cellular mechanisms, moving proteinstrands against one another using energy.

Locomotion

– is active travel from place to place and

– requires energy to overcome friction and gravity.

30.1 Locomotion requires energy to overcomefriction and gravity


An animal swimming is

– supported by water but

– slowed by friction.



Figure 30.1A

An animal walking, hopping, or running

– involves less overall friction between air and the animal,

– must resist gravity, and

– requires good balance.



Figure 30.1B

Figure 30.1C

An animal burrowing or crawling

– must overcome great friction between the animal andthe ground,

– is more stable with respect to gravity,

– may move by side-to-side undulations (such assnakes), or

– may move by a form of peristalsis (such as worms).



Figure 30.1D

Longitudinalmusclerelaxed(extended)

Circularmusclecontracted

Circularmusclerelaxed

Longitudinalmusclecontracted

Head

Bristles

1

2

3

An animal flying uses its wings as airfoils togenerate lift.

Flying has evolved in very few groups of animals.Flying animals include

– most insects,

– reptiles, including birds, and

– bats (mammals).



Figure 30.1E

Airfoil

Animal movement results from a collaborationbetween muscles and a skeletal system toovercome

– friction and

– gravity.



Skeletons provide

– body support,

– movement by working with muscles, and

– protection of internal organs.

There are three main types of animal skeletons:

– hydrostatic skeletons,

– exoskeletons, and

– endoskeletons.

30.2 Skeletons function in support, movement,and protection


1. Hydrostatic skeletons are

– fluid held under pressure in a closed bodycompartment and

– found in worms and cnidarians.

– Hydrostatic skeletons

– help protect other body parts by cushioning them fromshocks,

– give the body shape, and

– provide support for muscle action.



Figure 30.2A

2. Exoskeletons are rigid external skeletons thatconsist of

– chitin and protein in arthropods and

– calcium carbonate shells in molluscs.

– Exoskeletons must be shed to permit growth.



Figure 30.2B Figure 30.2C

Shell(exoskeleton)

Mantle

3. Endoskeletons consist of hard or leatherysupporting elements situated among the softtissues of an animal. They may be made of

– cartilage or cartilage and bone (vertebrates),

– spicules (sponges), or

– hard plates (echinoderms).



Figure 30.2D

Figure 30.2E

THE VERTEBRATESKELETON


The vertebrate skeletal system provided

– the structural support and

– means of location

– that enabled tetrapods to colonize land.

30.3 EVOLUTION CONNECTION: Vertebrateskeletons are variations on an ancient theme


The human skeleton consists of an

– axial skeleton

– that supports the axis or trunk of the body and

– consists of the skull, vertebrae, and ribs and

– appendicular skeleton

– that includes the appendages and the bones that anchor theappendage and

– consists of the arms, legs, shoulders, and pelvic girdles.



Figure 30.3A

Skull

Sternum

Ribs

Vertebra

Clavicle

ScapulaPectoralgirdle

Humerus

RadiusUlna

Pelvic girdle

Carpals

Phalanges

Metacarpals

Femur

Patella

Tibia

Fibula

TarsalsMetatarsalsPhalanges

Figure 30.3A_1

Skull

SternumRibs

Vertebra

Clavicle

ScapulaPectoralgirdle

Humerus

RadiusUlna

Pelvic girdle

Carpals

PhalangesMetacarpals

Figure 30.3A_2

Femur

Patella

Tibia

Fibula

TarsalsMetatarsalsPhalanges

Figure 30.3B

Intervertebraldiscs

7 cervicalvertebrae

12 thoracicvertebrae

5 lumbarvertebraeHip

bone Sacrum

Coccyx

Vertebrate bodies reveal variations of this basicskeletal arrangement.

Master control (homeotic) genes

– are active during early development and

– direct the arrangement of the skeleton.

– Vertebrate evolution has included changes in thesemaster control genes.



Figure 30.3C

Python Chicken

Cervicalvertebrae

Gene expressionduring development

Hoxc6

Hoxc8

Hoxc6 and Hoxc8

Thoracicvertebrae

Lumbarvertebrae

Thoracicver te

br

ea

Cartilage at the ends of bones

– cushions joints and

– reduces friction of movements.

Fibrous connective tissue covering most of theouter surface of bone forms new bone in the eventof a fracture.

30.4 Bones are complex living organs


Bone cells

– live in a matrix of flexible protein fibers and hardcalcium salts and

– are kept alive by blood vessels, hormones, and nerves.



Long bones have

– a central cavity storing fatty yellow bone marrow and

– spongy bone located at the ends of bones containingred bone marrow, a specialized tissue that producesblood cells.



Figure 30.4

Cartilage

Spongybone(contains redbone marrow)

Compactbone

Centralcavity

Yellowbone marrow

Fibrousconnectivetissue

Bloodvessels

Cartilage

Bone cells

– repair bones and

– reshape bones throughout life.

Broken bones

– are realigned and immobilized and

– bone cells build new bone, healing the break.

30.5 CONNECTION: Healthy bones resist stressand heal from injuries


Figure 30.5A

Osteoporosis is

– a bone disease,

– characterized by low bone mass and structuraldeterioration, and

– less likely if a person

– has high levels of calcium in the diet,

– exercises regularly, and

– does not smoke.

30.5 CONNECTION: Healthy bones resist stressand heal from injuries


Figure 30.5B

30.6 Joints permit different types of movement

Joints allow limited movement of bones.

Different joints permit various movements.

– Ball-and-socket joints enable rotation in the arms andlegs.

– Hinge joints in the elbows and knees permitmovement in a single plane.

– Pivot joints enable the rotation of the forearm at theelbow.


Figure 30.6

Headof humerus

Humerus

Scapula

Ulna

Ball-and-socket joint Hinge joint

Ulna

Pivot joint

Radius

MUSCLE CONTRACTIONAND MOVEMENT


Muscles and bones interact to produce movement.

Muscles

– are connected to bones by tendons and

– can only contract, requiring an antagonistic muscle to

– reverse the action and

– relengthen muscles.

30.7 The skeleton and muscles interact inmovement


Figure 30.7A

Biceps contracted,triceps relaxed(extended)

Biceps

Triceps

TendonsTriceps

Biceps

Tricepscontracted,bicepsrelaxed

Muscle fibers are cells that consist of bundles ofmyofibrils. Skeletal muscle cells

– are cylindrical,

– have many nuclei, and

– are oriented parallel to each other.

Myofibrils contain overlapping

– thick filaments composed primarily of the proteinmyosin and

– thin filaments composed primarily of the protein actin.

30.8 Each muscle cell has its own contractileapparatus


Sarcomeres are

– repeating groups of overlapping thick and thin filamentsand

– the contractile unit—the fundamental unit of muscleaction.

30.8 Each muscle cell has its own contractileapparatus


Figure 30.8

Muscle

Several muscle fibers

Single muscle fiber

(cell)

Plasma membrane

Nuclei

Myofibril

Lightband

Darkband

Lightband

Z line

Sarcomere

SarcomereZ lineZ line

Thickfilaments(myosin)

Thinfilaments(actin)

According to the sliding-filament model of musclecontraction, a sarcomere contracts (shortens)when its thin filaments slide across its thickfilaments.

– Contraction shortens the sarcomere without changingthe lengths of the thick and thin filaments.

– When the muscle is fully contracted, the thin filamentsoverlap in the middle of the sarcomere.

30.9 A muscle contracts when thin filaments slidealong thick filaments


Figure 30.9A

Relaxed muscle

Contractingmuscle

Fully contractedmuscle

Dark band

Sarcomere

Contracted sarcomere

Z Z

Myosin heads of the thick filaments

– bind ATP and

– extend to high-energy states.

Myosin heads then

– attach to binding sites on the actin molecules and

– pull the thin filaments toward the center of thesarcomere.

30.9 A muscle contracts when thin filaments slidealong thick filaments


Figure 30.9B

Thinfilaments

Thinfilament

Thickfilament

Thick filament

Z lineActin

Myosin head (low-energy configuration)

Myosin head (high-energy configuration)

Cross-bridge

Newpositionof Z lineThin filament moves

toward center of sarcomere.

1

2

3

ATP

ADPP

ADPP

4

ADP P

5

Myosin head (pivoting tolow-energy configuration)

ATP Myosin head (low-energy configuration)

A motor neuron

– carries an action potential to a muscle cell,

– releases the neurotransmitter acetylcholine from itssynaptic terminal, and

– initiates a muscle contraction.

30.10 Motor neurons stimulate muscle contraction


Figure 30.10A

Motor neuronaxon

Synapticterminal

T tubule

Action potential

Mitochondrion

Endoplasmicreticulum (ER)

Myofibril

Plasma membraneSarcomere

Ca2

releasedfrom ER

An action potential in a muscle cell

– passes along T tubules and

– into the center of the muscle fiber.

Calcium ions

– are released from the endoplasmic reticulum and

– initiate muscle contraction by moving the regulatoryprotein tropomyosin away from the myosin-binding siteson actin.



Figure 30.10B

Myosin-binding sites blocked

Myosin-binding sites exposed

Myosin-binding site

Ca2 floods thecytoplasmicfluid

Actin

Tropomyosin Ca2-binding sites

Troponin complex

A motor unit consists of

– a neuron and

– the set of muscle fibers it controls.

More forceful muscle contractions result whenadditional motor units are activated.



Figure 30.10CSpinal cord

Motor neuroncell body

Nerve

Motor neuronaxon

Synapticterminals

Muscle

Tendon

Muscle fibers(cells)

Nuclei

Bone

Motorunit 1

Motorunit 2

Aerobic respiration

– requires a constant supply of glucose and oxygen and

– provides most of the ATP used to power musclemovement during exercise.

The anaerobic process of lactic acid fermentation

– can provide ATP faster than aerobic respiration but

– is less efficient.

30.11 CONNECTION: Aerobic respirationsupplies most of the energy for exercise


Figure 30.11

Table 30.11

Depending on the pathway they use to generateATP, muscle fibers can be classified as

– slow,

– intermediate, or

– fast.

Most muscles have a combination of fiber types,which can be affected by exercise.

30.12 CONNECTION: Characteristics of musclefiber affect athletic performance


Table 30.12

Muscles can adapt to exercise by increasing the

– levels of myoglobin,

– number of mitochondria, and/or

– number of capillaries going to muscles.

30.12 CONNECTION: Characteristics of musclefiber affect athletic performance


Figure 30.12

SlowIntermediateFast

100

80

60

40

20

0World-class

sprinter

Averagecouchpotato

Averageactiveperson

Middle-distancerunner

World-class

marathonrunner

Extremeendurance

athlete

Perc

en

tag

eo

fto

talm

uscle

1. Describe the diverse methods of locomotion foundamong animals and the forces each method mustovercome.

2. Describe the three main types of skeletons, theiradvantages and disadvantages, and provideexamples of each.

3. Describe the common features of terrestrialvertebrate skeletons, distinguishing between theaxial and appendicular skeletons.

You should now be able to


4. Describe the complex structure of bone, notingthe major tissues and their relationship to blood-forming tissues.

5. Explain why bones break and how we can helpthem heal.

6. Describe three types of joints and provideexamples of each.

7. Explain how muscles and the skeleton interact toproduce movement.



8. Explain at the cellular level how a muscle cellcontracts.

9. Explain how a motor neuron signals a musclefiber to contract.

10. Describe the role of calcium in a musclecontraction.

11. Explain how motor units control musclecontraction.

12. Explain what causes muscle fatigue.



13. Distinguish between aerobic and anaerobicexercise, noting the advantages of each.

14. Compare the structure and functions of slow,intermediate, and fast muscle fibers.



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