926 Chapter 36

1 FOCUSObjectives36.2.1 Describe the three types of

muscle tissue.36.2.2 Explain how muscles contract.36.2.3 Explain why exercise is

important.

Vocabulary PreviewCall students’ attention to the termneuromuscular. Point out that theterm is made up of two parts, neuro-,which means “of or relating to thenervous system,” and muscular,which means “of or relating to themuscular system.” Ask: What do youthink the term neuromuscularmeans? (Of or relating to the nervousand muscular systems together)

Reading StrategyBefore students read the section,suggest that they rewrite the head-ings as how, why, or what questionsabout the muscular system. As theyread, they should write brief answersto their questions.

2 INSTRUCTTypes of MuscleTissueBuild Science SkillsInferring Show students a pictureof a person with larger-than-averagemuscles, such as a wrestler or weightlifter, and then show them a pictureof a person with average-sized mus-cles. Ask: Would you infer that theperson with larger muscles hasmore skeletal muscle cells?(Students are likely to say yes, eventhough the inference is incorrect.)Explain that most people have aboutthe same number of muscle cells,and then ask: In what other waycould muscles become larger? (Byincreasing the size of existing cells)

Section 36–2

Despite the fantasies of Hollywood horror films, a skeleton

cannot move by itself. Movement is the function of the

muscular system. More than 40 percent of the mass of the

average human body is muscle. The muscular system includes

the large muscles displayed by some athletes. It also includes

thousands of tiny muscles throughout the body that help to

regulate blood pressure, move food through the digestive sys-

tem, and power every movement of the body—from the blink of

an eye to the hint of a smile.

Types of Muscle TissueMuscle tissue is found everywhere in the body—not only just

beneath the skin but also deep within the body. There arethree different types of muscle tissue: skeletal, smooth,and cardiac. Each type of muscle is specialized for a specific

function in the body. Refer to Figure 36–6 as you read about the

different types of muscles.

Skeletal Muscles Skeletal muscles are usually attached

to bones. Skeletal muscles are responsible for such voluntary

movements as typing on a computer keyboard, dancing, or

winking an eye. When viewed under a microscope at high magni-

fication, skeletal muscle appears to have alternating light and

dark bands called striations. For this reason, skeletal muscle is

sometimes called striated muscle. Most skeletal muscles are

consciously controlled by the central nervous system.

Skeletal muscle cells are large, have many nuclei, and vary

in length from 1 millimeter to about 30 centimeters. Because

skeletal muscle cells are long and slender, they are often called

muscle fibers. Complete skeletal muscles consist of muscle

fibers, connective tissues, blood vessels, and nerves. Figure 36–7shows the structure of a skeletal muscle in the leg.

Key Concepts• What are the three types of

muscle tissue?• How do muscles contract?• Why is exercise important?

Vocabularymyosinactinneuromuscular junctionacetylcholinetendon

Reading Strategy:Summarizing As you read,find the main ideas for eachparagraph. Write down a fewkey words from each main idea.Then, use the key words in yoursummary. Reread your summary,keeping only the most impor-tant ideas.

Figure 36–6 There are threetypes of muscle tissue: skeletal,smooth, and cardiac. Skeletalmuscle cells have striations, or stripes,and many nuclei. Smooth musclecells are spindle-shaped and haveone nucleus and no striations.Cardiac muscle cells have striationsand usually only one nucleus.

Skeletal Muscle (150�) Smooth Muscle (400�) Cardiac Muscle (500�)

36–2 The Muscular System

SECTION RESOURCES

Print:

• Laboratory Manual B, Chapter 36 Lab• Teaching Resources, Lesson Plan 36–2,

Adapted Section Summary 36–2, AdaptedWorksheets 36–2, Section Summary 36–2,Worksheets 36–2, Section Review 36–2

• Reading and Study Workbook A, Section 36–2• Adapted Reading and Study Workbook B,

Section 36–2

Technology:

• iText, Section 36–2• Animated Biological Concepts DVD, 39

Muscle Contraction• Transparencies Plus, Section 36–2

Tim

eSaver

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Less Proficient ReadersUrge students to organize the information ontypes of muscle tissue in a compare/contrastmatrix. Their matrices should have columns fortype of tissue, how it is controlled, where it isfound, whether or not it is striated, whether itscells are small or large, and whether it has onenucleus or many nuclei. Check students’ com-pleted matrices for accuracy, and advise them tosave their matrices for review.

Advanced LearnersChallenge students to research the opposingmuscle groups in the human body. UsingInternet or library resources, they should findthe names, locations, and ranges of motion ofeach pair of opposing muscles. Have studentscreate a diagram or other visual representationof what they learn and share it with the rest ofthe class. Allow time for questions.

Bundle of muscle fibers

Actin

MyosinSkeletal muscle

Sarcomere

Z line

Myofibril

Muscle fiber (cell)

Smooth Muscles Smooth muscles are usually not under

voluntary control. A smooth muscle cell is spindle-shaped, has

one nucleus, and is not striated. Smooth muscles are found in

the walls of hollow structures such as the stomach, blood ves-

sels, and intestines. Smooth muscles move food through your

digestive tract, control the way blood flows through your circula-

tory system, and decrease the size of the pupils of your eyes in

bright light. Most smooth muscle cells can function without

nervous stimulation. They are connected to one another by gap

junctions that allow electrical impulses to travel directly from

one muscle cell to a neighboring muscle cell.

Cardiac Muscle Cardiac muscle is found in just one place in

the body—the heart. The prefix cardio comes from a Greek word

meaning “heart.” Cardiac muscle shares features with both

skeletal muscle and smooth muscle. Cardiac muscle is striated

like skeletal muscle, although its cells are smaller. Cardiac

muscle cells usually have one nucleus, but they may have two.

Cardiac muscle is similar to smooth muscle because it is usually

not under the direct control of the central nervous system and

cardiac cells are connected to their neighbors by gap junctions.

You will learn more about cardiac muscle in Chapter 37.

What kind of muscle tissue lines the blood vessels?

Skeletal muscles are made up of bundles of muscle fibers, which in turn are composed ofmyofibrils. Each myofibril contains thin filaments made of actin and thick filaments made ofmyosin. Muscle fibers are divided into functional units called sarcomeres. Applying ConceptsWhat nervous system structures carry messages to skeletal muscles?

For: Links on muscle contraction

Visit: www.SciLinks.orgWeb Code: cbn-0362

NSTA

FIGURE 36–7 SKELETAL MUSCLE STRUCTURE

Use VisualsFigure 36–7 Call students’ atten-tion to the figure, which they mightfind confusing. Check their under-standing by having them put thefollowing terms in order from largestto smallest: myosin, muscle fiber,skeletal muscle, myofibril. (Skeletalmuscle, muscle fiber, myofibril, myosin)Help students integrate the figurewith the text by asking: Which partof the drawing represents a singlemuscle cell? (The muscle fiber)

Build Science SkillsInferring Call students’ attention tothe similarities between cardiac muscle and skeletal muscle andbetween cardiac muscle and smoothmuscle. Ask: Why is it important forcardiac muscle to share these features with the other two typesof muscle? (The heart needs the fea-tures of skeletal muscle to perform thehard mechanical work of pumpingblood throughout the body. It needsthe features of smooth muscle to keepbeating continuously without voluntary control.)

Skeletal, Muscular, and Integumentary Systems 927

NSTA

Download a worksheet on muscle contraction for studentsto complete, and find additionalteacher support from NSTA SciLinks.

Answers to . . . Smooth muscle tissue

lines the blood vessels.

Figure 36–7 Motor neurons carrymessages to skeletal muscles.

UNIVERSAL ACCESS

0920_0936_bi_c07_te 3/13/06 2:10 PM Page 927

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Movement of Actin Filament

Muscle ContractionThe muscle fibers in skeletal muscles are composed of smaller

structures called myofibrils. Each myofibril is made up of even

smaller structures called filaments. The striations in skeletal

muscle cells are formed by an alternating pattern of thick and

thin filaments. The thick filaments contain a protein called

(MY-uh-sin). The thin filaments are made up mainly of

a protein called The filaments are arranged along the

muscle fiber in units called sarcomeres, which are separated

from each other by regions called Z lines. As Figure 36–8 shows,

when a muscle is relaxed, there are no thin filaments in the

center of a sarcomere.

The tiny myosin and actin filaments are the force-producing

engines that cause a muscle to contract. A muscle con-tracts when the thin filaments in the muscle fiber slideover the thick filaments. This process is called the sliding-

filament model of muscle contraction. For a muscle to contract,

the thick myosin filament must form a cross-bridge with the thin

actin filament. As the cross-bridge changes shape, it pulls on the

actin filament, which slides toward the center of the sarcomere.

The distance between the Z lines decreases. The cross-bridge

detaches from the actin filament. The cycle is repeated when the

myosin binds to another site on the actin filament.

When hundreds of thousands of myosin cross-bridges change

shape in a fraction of a second, the muscle fiber shortens with

considerable force. The energy for muscle contraction is supplied

by ATP. Because one molecule of ATP supplies the energy for one

interaction between a myosin cross-bridge and an actin filament,

the cell needs plenty of ATP molecules for a strong contraction.

Recall that the cell can produce ATP in two ways—by cellular

respiration and by fermentation.

What is actin? What is myosin?

actin.myosin

During muscle contraction, theknoblike head of a myosin filamentattaches to a binding site on actin,forming a cross-bridge.

Powered by ATP, the myosin cross-bridge changes shape and pulls theactin filament toward the center ofthe sarcomere.

The cross-bridge is broken, themyosin binds to another site on the actin filament, and the cyclebegins again.

Actin

Cross-bridges

Myosin

Contracted Muscle

Relaxed MuscleZ line

Z line

Z line

Sarcomere

Figure 36–8 During musclecontraction, the actin filamentsslide over the myosin filaments,decreasing the distance betweenthe Z lines.

928 Chapter 36

Muscle ContractionBuild Science SkillsInferring Point out to students thatthe description of muscle contractionin the text applies specifically toskeletal muscles, which are easy tostudy. Guide students in inferringwhether other muscles are likely tocontract in a similar way. First ask: Do you think that cardiac muscleor smooth muscles have alternat-ing bands of thick and thinfilaments as skeletal muscles do?(Students should infer that cardiacmuscle has the filaments because it isstriated like skeletal muscle, whereassmooth muscle lacks the filamentsbecause it is not striated.) Then, ask:Do you think that smooth musclesor cardiac muscle contracts in away that is similar to skeletal mus-cle contractions? (Students shouldinfer that cardiac muscle may contractin a similar way but that smooth mus-cles probably do not.)

Use VisualsFigure 36–8 Make sure studentsunderstand that the three illustra-tions across the bottom of the figureshow the sequence of events thatoccur during a muscle contraction.Help them integrate the top andbottom parts of the figure by asking:What effect does the movement ofthe actin filament have on the dis-tance between Z lines? (It shortensthe distance.) How does this affectthe muscle? (It causes the muscle tocontract.)

After teaching about muscle contraction, I chal-lenge students to defend one of two positionsregarding the best way to prepare for a work-out: first warm up and then stretch or firststretch and then warm up. I guide the class inconcluding that warming up should precedestretching, because a cold muscle cannot beadequately stretched. I also point out that astretched muscle can contract with greater forcethan a muscle that has not been stretched.

After teaching about the synapse and theenzyme cholinesterase, I ask students to predictwhat would happen if the enzyme were some-how inactivated. This facilitates studentunderstanding of muscle paralysis and theactions of insecticides and nerve gases.

—Thomas P. Rooney, Ph.D.Science Department ChairFather Judge High SchoolPhiladelphia, PA

TEACHER TO TEACHER

36–2 (continued)

0920_0936_bi_c07_te 3/13/06 2:10 PM Page 928

Control of Muscle ContractionSkeletal muscles are useful only if they contract

in a controlled fashion. Remember that motor

neurons connect the central nervous system to

skeletal muscle cells. Impulses from motor

neurons control the contraction of skeletal

muscle fibers.

Figure 36–9 shows a (noo-

roh-MUS-kyoo-lur) which is the point

of contact between a motor neuron and a skel-

etal muscle cell. Vesicles, or pockets, in the axon

terminals of the motor neuron release a neuro-

transmitter called (as-ih-til-KOH-leen).

Acetylcholine molecules diffuse across the synapse, producing

an impulse in the cell membrane of the muscle fiber. The

impulse causes the release of calcium ions (Ca2+) within the

fiber. The calcium ions affect regulatory proteins that allow

actin and myosin filaments to interact. From the time a nerve

impulse reaches a muscle cell, it is only a few milliseconds

before these events occur and the muscle cell contracts.

A muscle cell remains contracted until the release of

acetylcholine stops and an enzyme produced at the axon

terminal destroys any remaining acetylcholine. Then, the cell

pumps calcium ions back into storage, the cross-bridges stop

forming, and contraction ends.

What is the difference between a strong contraction and a

weak contraction? Each muscle contains hundreds of cells.

When you lift something light, such as a sheet of paper, your

brain stimulates only a few cells in your arm muscles to

contract. However, as you exert maximum effort, as the rock

climber in Figure 36–10 is doing, almost all the muscle cells in

your arm are stimulated to contract.

acetylcholine

junction,neuromuscular

� Figure 36–9 The long greenaxon of a motor neuron makescontact with a long pink musclefiber at the neuromuscular junction.(Note that color has been added tothis SEM.)

� Figure 36–10 Because this rock climberexercises regularly, her muscles are firm and haveincreased in size. Predicting What would happento her muscles if she stopped exercising regularly?

Control of MuscleContractionMake ConnectionsHealth Science Help studentsrelate nervous control of muscles tohealth issues. Point out that manycases of paralysis occur as a result ofspinal cord injuries. Remind studentsthat the spinal cord carries nerveimpulses from the brain to otherparts of the body. Ask: How does aspinal cord injury cause paralysis ofthe legs? (The injury interrupts thepathway of impulses from the brain tothe nerves that control muscles in thelegs. Without impulses from the nerves,the muscles cannot contract, andparalysis results.)

DemonstrationUse a simple demonstration toemphasize the role of the centralnervous system in muscle contrac-tion. Hold a small, closed box thatcontains a book or other object. Tellthe class that the box is empty and,therefore, very light in weight. Then,hand the box to a volunteer whilethe other students watch. Being prepared for a lightweight object, thevolunteer is likely to nearly drop thebox before realizing that it is heavyand compensating for the unex-pected weight. Ask: What wouldhave happened if the volunteerhad known the box was heavyinstead of light? (The volunteer’s cen-tral nervous system would have beenprepared to stimulate more muscle cellsto contract before he or she took thebox.)

A painter and a poisonOne of the earliest scientists to study and correctlyportray the human muscular system was theItalian artist Leonardo da Vinci, who livedbetween 1452 and 1519. Up until da Vinci’s time, knowledge of the muscular system wasbased as much on myth as on fact. Da Vinci’sknowledge of the muscular system, in contrast,was based on dissections, and his drawings of themuscles were accurate as well as beautiful. In the

mid-1800s, the role of nerves in the contractionof skeletal muscles was established by a scientistnamed Claude Bernard, who did experimentsusing a drug called curare. Curare blocks thetransmission of nerve impulses, and it was used bysome Amazonian Native Americans to poison thetips of their hunting arrows. Bernard injectedcurare into muscles and found that the musclesbecame paralyzed when nerve impulses wereblocked by the drug.

HISTORY OF SCIENCE

Skeletal, Muscular, and Integumentary Systems 929

Answers to . . . Actin is the protein in

the thin filaments of skeletal muscles.Myosin is the protein that makes upthe thick filaments of skeletal muscles.

Figure 36–10 Her muscles woulddecrease in size.

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What do tendons do?

Materials raw chicken wing treated with bleach,paper towels, forceps, scissors, scalpel

Procedure

1. Put on the plastic gloves and lab apron. CAUTION:Do not touch your face with your hands during thelab. Be careful with the scissors and scalpel.

2. Put a chicken wing on a paper towel. Peel back orcut away the skin and fat of the largest wingsegment to expose the large muscle. This muscle iscalled the biceps. Find the tendon that attaches thebiceps to the bones of the middle segment of thewing. Tendons are the tough, shiny white cordsthat join the muscles to the bones.

3. Use forceps to pull on the tendon of the biceps andobserve what happens to the chicken wing.

4. Clean your tools and dispose of the chicken wingand gloves according to your teacher’s instructions.Wash your hands with soap and warm water.

5. Next, observe the back of your hand as you moveeach of your fingers in turn. Compare what you seeto how the chicken wing moved.

Analyze and Conclude1. Applying Concepts What happened when you

pulled on the tendon? In a live chicken, what struc-ture would pull on the tendon to move the wing?

2. Comparing and Contrasting How is the waythe wing moves similar to the way your fingersmove?

How Muscles and Bones InteractSkeletal muscles generate force and produce movement by

contracting, or pulling on body parts. Individual muscles can

only pull in one direction. Yet, you know from experience that

your legs bend when you sit and extend when you stand up.

How is this possible?

Skeletal muscles are joined to bones by tough connective

tissues called Tendons are attached in such a way

that they pull on the bones and make them work like levers.

The joint functions as a fulcrum—the fixed point around which

the lever moves. The muscles provide the force to move the

lever. Usually, there are several muscles surrounding each joint

that pull in different directions.

Most skeletal muscles work in opposing pairs. When one

muscle contracts, the other relaxes. The muscles of the upper

arm shown in Figure 36–11 are a good example of this dual

action. When the biceps muscle contracts, it bends, or flexes,

the elbow joint. When the triceps muscle contracts, it opens,

or extends, the elbow joint. A controlled movement, however,

requires contraction by both muscles. To hold a tennis racket

or a violin, both the biceps and triceps must contract in balance.

This is why the training of athletes and musicians is so difficult.

The brain must learn how to work opposing muscle groups in

just the right ways to make the joint move precisely.

tendons.

Biceps

Tendon

930 Chapter 36

How Muscles and Bones Interact

All about musclesThere are about 600 different muscles in thehuman body and an astounding 6 trillion individ-ual muscle fibers. The largest muscle is thegluteus maximus, covering the buttocks. Thesmallest is the stapedius, located in the middleear. Contrary to popular belief, muscles are notmade up mostly of protein. Protein makes up only about 20 percent of muscle. Water makes up most of the rest. Muscles are surprisingly

inefficient. Even under ideal conditions, more thanhalf the total chemical energy used by muscles islost in the form of heat. After playing squash forjust 7 minutes, a 62-kilogram person producesenough heat to raise the temperature of 91 litersof water by 1°C. Although most people completetheir growth in body size by age 20, muscularstrength keeps increasing, usually peaking some-time between the ages of 20 and 30.

FACTS AND FIGURES

36–2 (continued)

Objective Students will be able tocompare and contrast movementsof the tendons that control chickenwings and their own fingers.Skill Focus Applying Concepts,Comparing and ContrastingMaterials plastic gloves, raw chicken wing treated with bleach,paper towels, forceps, scissors,scalpelTime 20 minutesAdvance Prep Briefly soak thewings in bleach to kill any surfacebacteria. Then, rinse them thor-oughly in water and dry them. Ifyou do not use the wings immedi-ately, refrigerate them until you do.Safety All work surfaces should bedisinfected at the end of the lab.Dispose of the chicken parts properly.Strategies• If necessary, help students find the

biceps muscle in the chicken wing.• Students can observe the tendons

that control their fingers by watch-ing the backs of their hands as they drum their fingers on theirdesks.

Expected Outcomes Studentsshould observe that pulling on thetendon in the wing causes the wingto bend and that bending their fin-gers causes the tendons in theirhands to move.Analyze and Conclude1. The wing bent at the joint. In alive chicken, the biceps muscle would pull on the tendon.2. Like the chicken’s biceps muscle,muscles controlling the fingers causethe fingers to bend by pulling ontendons.

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36–2 Section Assessment1. Skeletal, which controls voluntary move-

ments; smooth, which controls involuntarymovements; and cardiac, which controlscontractions of the heart

2. Myosin cross-bridges cause the thin fila-ments to slide over the thick filaments,shortening the muscle.

3. It maintains muscular and skeletal strength;increases coordination, endurance, and flexibility; and decreases body fat.

4. To control body movement, help circulateblood, and help move food through thedigestive system

5. Acetylcholine is a neurotransmitter. It diffusesacross nerve synapses to produce impulses inmuscle cell membranes.

6. No; it must relax before it can respond to asecond impulse.

Exercise and HealthSkeletal muscles generally remain in a state of partial contrac-

tion called resting muscle tone. Muscle tone is responsible for

keeping the back and legs straight and the head upright, even

when you are relaxed.

Regular exercise is important in maintainingmuscular strength and flexibility. Muscles that are exer-

cised regularly stay firm and increase in size and strength by

adding actin and myosin filaments. Muscles that are not used

become weak and can visibly decrease in size.

Aerobic exercises—such as running and swimming—cause

the body’s systems to become more efficient. For example,

aerobic exercise helps your heart and lungs become more effi-

cient. This, in turn, increases physical endurance—the ability to

perform an activity without fatigue. Regular exercise also

strengthens your bones, making them thicker and stronger.

Strong bones and muscles are less likely to become injured.

Resistance exercises, such as weight lifting, increase muscle

size and strength. Resistance exercises also decrease body fat

and increase muscle mass. Over time, weight-training exercises

will help to maintain coordination and flexibility.

Movement

Movement

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� Figure 36–11 By contractingand relaxing, the triceps and bicepsin the upper arm enable you to bendor straighten your elbow. ApplyingConcepts Which skeletal musclemust contract in order for you tostraighten your elbow?

1. Key Concept List thethree types of muscle tissue andexplain the function of each.

2. Key Concept Explain howa muscle contracts.

3. Key Concept Describe theimportance of regular exercise.

4. What is the function of themuscular system?

5. What is the role of acetylcholine inthe process of muscle contraction?

6. Critical Thinking PredictingIf a muscle cell receives a secondstimulus while it is contracting,will it respond to the secondstimulus? Explain.

Using Models Create your own model toshow how actin filaments slideover myosin filaments duringa muscle contraction. Includeas much detail in your modelas possible.

36–2 Section Assessment

Skeletal, Muscular, and Integumentary Systems 931

Answer to . . . Figure 36–11 The triceps musclemust contract to straighten your elbow.

Exercise and HealthUse Community ResourcesInvite a physical therapist, personaltrainer, or other exercise specialist tospeak to the class about exercising toincrease and maintain muscle sizeand strength. Ask the speaker to tailor the message to high-schoolstudents. If possible, have the speaker demonstrate exercises tohelp maintain muscle tone and prevent injury. Urge students to askquestions at the end of the talk.

3 ASSESSEvaluate UnderstandingHave students make Venn diagramscomparing and contrasting skeletalmuscle tissue, smooth muscle tissue,and cardiac muscle tissue.

ReteachUsing the chalkboard or a trans-parency, work with the class to makea flowchart showing how a motorneuron stimulates a muscle cell.

The models should illustrate thefollowing: A cross-bridge formsbetween the actin and myosin fila-ments. When the cross-bridgebends, the actin slides over themyosin. Then, the cross-bridgedetaches, unbends, and reattachesto a new site on the actin.

If your class subscribes to the iText,use it to review the Key Concepts inSection 36–2.

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The skin is not only the largest organ in the

body, it is also one of the most easily injured,

especially by fire. More than 2 million Americans

suffer burn injuries every year, and more than

10,000 die from such injuries. The skin is the

body’s most important barrier against infection,

but burns can destroy that barrier, leaving tissues

exposed and vulnerable.

The best way to protect badly burned tissue is to

cover it with a layer of fresh skin. If the burned

region is small, this can be done with skin grafts

taken from other parts of the body. For larger

burns, however, this isn’t possible. Scientists have

developed a way to help many victims of serious

burns—they have developed artificial skin.

Constructing a ScaffoldSkin is a complex organ. For this reason, research-

ers realized that the best way to replace skin

would be with an artificial skin that the body’s own

cells could grow into. After the outer layer of

burned tissue is removed from a severely burned

patient, surgeons can apply artificial skin made

from a biodegradable meshwork of protein fibers

similar to those in human skin. Cells from the der-

mis migrate upward and gradually “take over” the

artificial layer, replacing the meshwork with

human proteins. Thus, a new layer of dermis is

produced. A very thin layer of the patient’s own

epidermal cells, grown in culture, is then applied

to the surface of the artificial skin.

Perfecting the TechniqueArtificial skin is used only in the treatment of

burns so severe that normal healing is not pos-

sible. One of its main drawbacks is that the migra-

tion of cells into the artificial layer may take as

long as three weeks, enough time for infection and

other complications to develop. Researchers are

trying to speed up the process by placing cell-

growth signal chemicals in the artificial layer.

If they succeed, the successful treatment of even

serious burns may become routine.

Research and DecideUse library or Internet references to learn more

about artifical skin and how it is used for the treat-

ment of serious burns. Design a brochure that

explains and illustrates the steps in the treatment

of third-degree burns.

Making Artificial Skin

For: Links from the authorsVisit: PHSchool.comWeb Code: cbe-0363

932 Chapter 36

Students will get more out of thefeature if they first read Section36–3. After students have read thefeature, you might want to discussone or more of the following:• How burns are classified based on

the degree of skin damage theycause, as first-degree, second-degree, or third-degree burns, withthird-degree burns being the mostserious

• How burns that affect the dermisdiffer from burns that affect onlythe epidermis

• What causes burns, includingmatches, flammable liquids, hotwater, and steam

• How students can prevent burns,for example, by following packageprecautions when using flammableliquids and testing bathwaterbefore getting in

Research and DecideStudents are likely to find the mostup-to-date information on artificialskin on the Internet. Useful Web sitesinclude those of the Shriners and theNational Institute of General MedicalSciences. Students’ brochures shouldinclude the following steps: coveringthe burn to help prevent infection;elevating the hands and feet to helpprevent shock; getting the victim toa hospital as soon as possible; andreplacing the burned skin with a newbarrier against infection, using eitherskin grafts or artificial skin.

Students can research artificialskin on the site developed byauthors Ken Miller and Joe Levine.

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