Human Anatomy: Ch 10 - Skeletal Muscle Tissue

Sarcomeres (from PP slide)

1. Basic unit of contraction. 2. Z disc are ends of each sarcomere; myofilaments attach to these discs. 3. Has thin and thick filaments. 4. Dark bands created by full length of thick filaments and the inner ends of the thin filaments which overlap the thick filaments. This area is called the "A band."

Info on Connective Tissue (from PP slide)

1. Binds each muscle with fiber together and holds them in parallel alignment so they can work together and produce force. 2. These sheaths are continuous with each other. 3. The three sheaths converge to form the tendon (connective tissue structure that connects muscle to bones). 4. Sheaths also provide muscle with elasticity and carry the blood vessel and nerves. 5. When muscle fibers contract, they pull on the endomysium which then pulls on the perimysium then the epimysium, then on the tendon.

Sarcomeres Cont. (from PP slide)

1. Central part of the A Band where no thin filaments are is called the "H zone." 2. M line is the center of the H zone and contains tiny rods that hold the thick filaments together. 3. I Bands are the two regions on either side of the A Band and contain only thin filaments. I Bands create the light portion of the striation.

Thick filaments

1. Consist largely of myosin molecules 2. Contains ATPase enzymes that split ATP to release energy needed for contraction. 3. Each end of the thick filament has myosin heads.

List 4 functional properties of muscle tissue that distinguish it from other tissue.

1. Contractility 2. Excitability 3. Extensibility 4. Elasticity

Myofibrils

1. Give the muscle the striation appearance. 2. Long rod shaped. 3. Make up 80% of sarcoplasm 4. Contain myofilaments 5. Contains mitochondria and glycosomes; both supply energy for contraction. 6. Has repeating segments called sarcomeres.

Info on Blood Vessels and Nerves (from PP slide)

1. In general, most muscles are supplied by 1 nerve, 1 artery, and 1 or more veins. All of these usually enter or exit the muscle near the middle of the length. 2. Nerve and vessels branch off repeatedly in the intramuscular connective tissue. 3. Rich blood supply to muscles reflects the high demand that contracting muscle fibers have for nutrients and oxygen.

Info on Muscle Attachments (from PP slide)

1. Location on the bone where a muscle connects to the bone. 2. Each skeletal muscle extends from one bone to another, crossing at least one moveable joint. 3. When muscle contracts, one bone will move while the other usually remains fixed.

Describe skeletal muscle tissue.

1. Makes up 40% of body weight. 2. Muscle cells are called striated muscle. 3. Elongated, cylindrical skeletal muscles are called muscle fibers. 4. Voluntary muscles.

Muscle Attachments Cont. (from PP slide)

1. Most tendons and aponeurosis attach to bones. They can also attach to skin, cartilage, and sheets of fascia or to raphe.

Describe Smooth muscle tissue.

1. Mostly found in walls of hollow internal organs other than the heart. 2. Not striated muscles but does have the elongated muscle fibers. 3. Involuntary muscles.

Muscle Attachments Cont. - Attachment (from PP slide)

1. Muscles attach to their origins and insertions by strong connective tissue that extends into the periosteum of the bone. 2. Direct attachments at the attaching strands of connective tissue are so short that the muscle fascicles themselves appear to attach directly to the bone. 3. Indirect attachments at the connective tissue extends well beyond the end of the muscle fibers to form either a cord-like tendon or a flat sheet called aponeurosis. 4. Indirect attachments are more common and most muscles have tendons.

Name the proteins found in the two types of myofilaments responsible for shortening of the muscle cells.

1. One myofilament contains actin. 2. The other myofilament contains myosin.

Info on Muscle Attachments Cont. - Origin/Insertion (from PP slide)

1. Origin is the muscle attachment on the fixed/less moveable bone. 2. Insertion is the muscle attachment on the more movable bone. 3. When a muscle contracts, it's insertion is pulled toward it's origin.

Expand of the muscle function of movement production.

1. Skeletal muscles attach to bones. 2. Walls of visceral organs squeeze to produce movement/passage of items (peristalsis)

Examples of the muscle function of opening and closing body passageways include:

1. Sphincter Muscles 2. Muscles around mouth and eyes. 3. Iris of the eye

Describe Cardiac muscle tissue.

1. Wall of the heart. 2. Muscle cells are striated muscles. 3. Involuntary muscles.

Thin filaments

1. are composed mostly of actin 2. 2 regulatory proteins (troponin and tropomyosin) regulate interaction with thick filaments.

From external to internal, connective tissue and fascicles are:

1. epimysium 2. perimysium 3. endomysium

Muscle Fiber

1. long cylindrical cells 2. Contain many nuclei that are located at the periphery of each fiber myofibrils.

Skeletal muscles contain:

1. muscle tissue 2. connective tissue 3. blood vessels 4. nerves

Functions of muscle tissue include:

1. produce movement 2. open and close body passageways 3. maintain posture and stabilize joints 4. generate heat

List the types of muscle tissue.

1. skeletal muscle tissue 2. cardiac muscle tissue 3. smooth muscle tissue

What types of muscle tissue are involuntary?

Cardiac muscle and smooth muscle tissue

Describe muscle fibers.

Cylindrical and elongated muscle cells

What initiates contraction?

Excitability

Actin and myosin are two proteins that do what?

Generate contractile force.

About how much of the body's mass is made up of muscles?

Nearly half

Excitability is

Nerve signals or other stimuli excite muscle cells causing electrical impulses to travel along the cells plasma membrane

What kind of muscle tissue makes up about 40% of body weight?

Skeletal muscle

What types of muscle tissue are voluntary?

Skeletal muscle

What types of muscle tissue have elongated muscle fibers?

Skeletal muscle tissue and smooth muscle tissue.

What muscle tissue does not have elongated muscle fibers?

Smooth muscle tissue

Titin filaments (from PP slide)

TITIN- SPRINGLIKE MOLECULE IN SARCOMERES THAT RESIST OVERSTRETCHING • FOUND IN ELASTIC FILAMENTS • EXTEND FROM Z DISC TO THE THICK FILAMENT AND RUN WITH THE THICK FILAMENTS TO ATTACH TO THE M LINE • LARGEST PROTEIN EVER DISCOVERED • STRONGLY RESIST EXCESSIVE STRETCHING • 2 FUNCTIONS • HOLD THICK FILAMENTS IN PLACE IN SARCOMERE • UNFOLDS WHEN MUSCLE IS STRETCHED AND REFOLDS WHEN STRETCHING FORCE IS RELEASED

myofilaments

The contractile proteins, actin and myosin, of muscle cells

There is an "A" in dark, thus Dark Bands are A Bands; and

There is an "I" in light, thus the light bands are I Bands.

Muscle fibers are separated into groups. (T/F)

True

The endomysium is within each fascicle. (T/F)

True

What two types of muscle tissue are collectively called visceral muscles?

cardiac and smooth muscles

Extensibility is

contraction of one muscle stretches an opposing one

sarcoplasmic reticulum

endoplasmic reticulum that is specialized for storage of calcium

Fascicle is

group or bundle of muscle fibers that are encased in the perimysium.

sarco-

means flesh and refers to muscles

Muscles are composed of

muscle cells and surrounding connective tissue

Elasticity is

muscle cells will recoil passively and return to its resting length after being stretched.

Contractility is most highly developed in __.

muscle cells.

Biarticular or multijoint muscles

muscle spans two or more joints.

Contractibility is

muscle tissue contracts forcefully

Extensibility allows

organs to be stretched by other factors like food or urine.

Epimysium is the

outer layer of dense irregular connective tissue that surrounds the whole skeletal muscle. This layer sometimes can blend with the deep fascia that lies between neighboring muscles.

sarcolemma

plasma membrane of muscle cells

Myo-

prefix for muscle

Raphe

seam of fibrous tissue that muscles sometimes attach to.

Connective Tissue and Fascicles are

several sheaths of connective tissue that hold the fibers of a skeletal muscle together.

What type of muscle cells do skeletal and cardiac muscle tissue have?

striated muscle cells

sarcoplasm

the cytoplasm in muscle tissue

Endomysium is

the layer of connective tissue surrounding individual muscle fibers. In this layer, each muscle fiber is surrounded by a fine sheath of loose connective tissue consisting mostly of reticular fibers.

Perimysium is the

the layer of fibrous connective tissue that surrounds each fascicle and are within each skeletal muscle.

Contractility muscles contain

two types of myofilaments that are responsible for shortening of the muscles.

Mechanisms of Contraction (from PP slide)

• 2 TYPES OF MUSCLE CONTRACTION INVOLVED TO PRODUCE MOVEMENT • CONCENTRIC CONTRACTION • MUSCLE SHORTENS AND DOES WORK • ECCENTRIC CONTRACTION • MUSCLE LENGTHENS

Eccentric Contraction (from PP slide)

• A MUSCLE GENERATES FORCE WHILE LENGTHENING • THIS TYPE OF CONTRACTION IS ESSENTIAL FOR CONTROLLED MOVEMENTS AND RESISTANCE TO GRAVITY • LESS UNDERSTOOD THAN CONCENTRIC CONTRACTION • THIS HAPPENS ANYTIME THE MUSCLES ARE ACTING AS A BRAKE

Motor Unit (from PP slide)

• AXON OF A MOTOR NEURON BRANCHES TO INNERVATE A NUMBER OFFIBERS IN A SKELETAL MUSCLE • THE MOTOR NEURON AND ALL THE MUSCLE FIBERS IT INNERVATES ARE THE MOTOR UNIT • WHEN A MOTOR NEURON FIRES ALL THE SKELETAL MUSCLE FIBERS IN THE MOTOR UNIT CONTRACT TOGETHER • AVERAGE NUMBER OF MUSCLE FIBERS IN A MOTOR UNIT IS 150, THAT NUMBER CAN RANGE AS HIGH AS SEVERAL HUNDRED AND TO AS LOW AS FOUR. • MUSCLES THAT REQUIRE VERY FINE CONTROL HAVE FEW MUSCLE FIBERS PER UNIT • FIBERS OF A MOTOR UNIT ARE NOT CLUMPED TOGETHER THEY ARE SPREAD OUT SO STIMULATION OF A MOTOR UNIT RESULTS IN A WEAK CONTRACTION OF THE MUSCLE • EACH MUSCLE CONTAINS SEVERAL MOTOR UNITS • RECRUITMENT IS THE ADDITION OF MOTOR UNITS TO ACCOMPLISH A MOVEMENT

Concentric Contraction Cont. (from PP slide)

• CONTRACTION AFFECTS THE STRIATION PATTERN • FULLY RELAXED SARCOMERE THE THIN FILAMENTS PARTIALLY OVERLAP THE THICK FILAMENTS • CONTRACTED MUSCLE THE THICK FILAMENTS FORCEFULLY PULL THE TWO Z DISC CLOSER CAUSING THE SARCOMERE TO SHORTEN

Neuromuscular Junction (from PP slide)

• EACH MUSCLE FIBER IN A SKELETAL MUSCLE IS SERVED BY A NERVE ENDING WHICH SIGNALS THE FIBER TO CONTRACT • WHERE THE NERVE ENDING AND MUSCLE FIBER MEET IS THE NEUROMUSCULAR JUNCTION • THE NERVE PORTION IS A CLUSTER OF ENLARGEMENTS (TERMINAL BOUTONS) AT THE END OF THE AXONAL PROCESS THAT STORES CHEMICAL MESSENGER MOLECULES (NEUROTRANSMITTERS) • TERMINAL BOUTONS ARE SEPARATED FROM THE SARCOLEMMA OF THE MUSCLE FIBER BY A SPACE CALLED SYNAPTIC CLEFT

SARCOPLASMIC RETICULUM AND T TUBULES (from PP slide)

• EACH SKELETAL MUSCLE FIBER HAS 2 SETS OF TUBULES THAT PARTICIPATE IN REGULATING MUSCLE CONTRACTION • SARCOPLASMIC RETICULUM- SMOOTH ENDOPLASMIC RETICULUM SURROUNDING EACH MYOFIBRIL • MOST RUN LONGITUDINALLY ALONG THE MYOFIBRILS • TERMINAL CISTERNS-FORM LARGE PERPENDICULAR CROSS CHANNELS OVER THE JUNCTION BETWEEN EACH A BAND AND ITS ADJACENT I BAND • HOLDS LARGE AMOUNTS OF CALCIUM AND ITS RELEASED WHEN THE MUSCLE CONTRACTS • T-TUBULES - DEEP IN THE SARCOLEMMA THAT RUN BETWEEN EACH PAIR OF TERMINAL CISTERNS • TRIAD- THE T TUBULE FLANKED BY TWO TERMINAL CISTERNS AT THE A-I JUNCTION • CONDUCT NERVE IMPULSES TO DEEPER REGIONS OF THE MUSCLE FIBER • STIMULATE RELEASE OF CALCIUM FROM TERMINAL CISTERNS

Slow Oxidative Fibers (from PP slide)

• GET ENERGY FROM AEROBIC METABOLIC REACTIONS • RELATIVELY HIGH NUMBER OF MITOCHONDRIA (SITE OF AEROBIC METABOLISM) • RICH SUPPLY OF CAPILLARIES • THIN FIBERS ARE RED DUE TO ABUNDANT AMOUNT OF MYOGLOBIN (OXYGEN BINDING PIGMENT) IN THE SARCOPLASM • CONTRACT SLOWLY, EXTREMELY RESISTANT TO FATIGUE AS LONG AS THERE IS ENOUGH OXYGEN PRESENT, DELIVERS PROLONGED CONTRACTION, THEY DO NOT GENERATE MUCH POWER DUE TO THIN SLOW OXIDATIVE FIBERS • FIND THESE FIBERS IN THE POSTURAL MUSCLES OF THE LOW BACK

Innervations of Skeletal Muscles (from PP slide)

• MOTOR NEURONS - NERVE CELLS THAT INNERVATE MUSCLE FIBERS • NEURON HAS CELL PROCESSES THAT EXTEND FROM THE CELL BODY • DENDRITES ARE RECEPTIVE REGIONS OF THE NEURON • AXON IS LONG SINGULAR CELL PROCESS THAT INITIATES AND TRANSMITS NERVE IMPULSES

Concentric Contraction (from PP slide)

• MUSCLE GENERATES FORCE WHILE SHORTENING • USE OF THE SLIDING FILAMENT MECHANISM • INITIATED BY RELEASE OF CALCIUM FROM SARCOPLASMIC RETICULUM AND BINDING TO THE MOLECULE TROPONIN IN THE THIN FILAMENT • THIS RESULTS IN A CHANGE OF SHAPE OF THE TROPONIN WHICH MOVES THE TROPOMYOSIN MOLECULE AND EXPOSES THE BINDING SITED OF ACTIN FILAMENTS FOR THE MYOSIN HEAD • CONTRACTION RESULTS AS THE MYOSIN HEADS OF THE THICK FILAMENT ATTACH TO THE THIN FILAMENTS AT BOTH ENDS OF THE SARCOMERE AND PULL THE THIN FILAMENTS TOWARD THE CENTER OF THE SARCOMERE BY PIVOTING INWARD • AFTER MYOSIN HEAD PIVOTS AT ITS "HINGE"IT LETS GO, RETURNS TO ITS ORIGINAL POSITION, BINDS TO THE THIN FILAMENT FARTHER ALONG ITS LENGTH AND PIVOTS AGAIN, THIS RATCHET TYPE MECHANISM OCCURS MANY TIMES IN A SINGLE CONTRACTIOM • ATP POWERS THIS PROCESS • THE THICK AND THIN FILAMENTS DO NOT SHORTEN THE THIN FILAMENT MERELY SLIDES OVER THE THICK FILAMENT

Muscles (from PP slide)

• MUSCLES CONTAIN A MIXTURE OF THE THREE FIBER TYPES SO THEY CAN PERFORM DIFFERENT TASKS AT DIFFERENT TIMES • SOME CAN HAVE MORE OF ONE TYPE OF MUSCLE THAN THE OTHERS, THIS IS GENETIC AND CAN AFFECT ATHLETIC ABILITY • YOU CAN TRANSFORM MUSCLE FIBER TYPES THROUGH TRAINING, SPECIFICALLY INTENSE RESISTANCE TRAINING CAN CONVERT FAST GLYCOLYTIC TO FAST OXIDATIVE , THESE FIBERS WILL RETURN TO ORIGINAL WHEN TRAINING STOPS HOWEVER • WEIGHT TRAINING INCREASES THE DIAMETER AND STRENGTH OF FAST MUSCLE FIBERS

Skeletal Muscle Tissue Through Life (from PP slide)

• MUSCLES DEVELOP FROM MYOBLAST, THEY FUSE TO FORM MUSCLE FIBERS, THIS FUSION IS WHY MUSCLE FIBERS ARE MULTINUCLEATED • MUSCLES ARE CONTRACTING BY WEEK 7 EMBRYOLOGICALLY • NERVES GROW INTO MUSCLE MASSES FROM SPINAL CORD • MUSCLES LENGTHEN AND THICKEN TO KEEP UP WITH GROWING BODY • STRENGTH OF SKELETAL MUSCLES DIFFERS IN MEN AND WOMEN • ON AVERAGE THE BODY STRENGTH OF ADULT MEN IS GREATER THAN ADULT FEMALES • WOMEN'S MUSCLE MASS MAKES UP ABOUT 36% OF BODY MASS • MEN'S MUSCLE MASS MAKES UP ABOUT 42%OF BODY MASS

Disorders of Skeletal Muscle Tissue (from PP slide)

• MUSCULAR DYSTROPHY • A GROUP OFINHERITED MUSCLE DESTROYING DISEASES THAT GENERALLY APPEAR IN CHILDHOOD • AFFECTED MUSCLES ENLARGE WITH FAT AND CONNECTIVE TISSUE WHILE MUSCLE FIBERS DEGENERATE • MOST COMMON FORM IS DUCHENNE MUSCULAR DYSTROPHY • INHERITED AS A SEX-LINKED RECESSIVE DISEASE • FEMALES CARRY AND TRANSMIT THE DISEASE BUT IT'S EXPRESSED ALMOST EXCLUSIVELY IN MALES • DIAGNOSED BETWEEN 2-7 YEARS OLD. ACTIVE NORMAL CHILDREN SUDDENLY BECOME CLUMSY AND START TO FALL FREQUENTLY AS THEIR MUSCLES WEAKEN • MYOTONIC DYSTROPHY CAN APPEAR BETWEEN BIRTH TO AGE 60, INHERITED AND SLOW PROGRESSING. SYMPTOMS INCLUDE MUSCLE SPASMS FOLLOWED BY MUSCLE WEAKNESS AND ABNORMAL HEART RYTHEM

Fibromyalgia (from PP slide)

• MYSTERIOUS CHRONIC PAIN SYNDROME OF UNKNOWN CAUSE • SYMPTOMS INCLUDE SEVERE MUSCULOSKELETAL PAIN,FATIGUE, SLEEP ABNORMALITIES AND HEADACHES • AFFECTS 2%OF ALL PEOPLE MOSTLY WOMEN • MOST COMMON SITE OF PAIN IS THE LOW BACK OR NECK • TO IDENTIFY THIS CONDITION PAIN MUST BE PRESENT IN AT LEAST 11 OF 18 STANDARDIZED POINTS THA ARE SPREAD WIDELY OVER THE BODY

Muscle Fiber Length and Force of Contraction (from PP slide)

• OPTIMAL RESTING LENGTH OF A MUSCLE FIBER IS THE LENGTH THAT WILL GENERATE THE GREATEST PULLING FORCE WHEN THE MUSCLE IS CONTRACTED • THIS OPTIMAL LENGTH OCCURS WHEN THE FIBER IS SLIGHTLY STRETCHED SO THAT ITS THIN AND THICK FILAMENTS OVERLAP TO ONLY A MODERATE EXTENT • WHAT IS TRUE OF MUSCLE FIBERS IS TRUE FOR THE ENTIRE MUSCLES ALSO. WHOLE SKELETAL MUSCLES HAVE A RANGE OF OPTIMAL OPERATING LENGTH THAT RUNS FROM ABOUT 80% OF THEIR NORMAL RESTING LENGTH TO ABOUT 120% OF THAT LENGTH

Types of Muscle Fibers Cont. (From PP slide)

• OXIDATIVE FIBERS-FIBERS PREDOMINANTLY PRODUCE ATP AEROBICALLY (USING OXYGEN) • GLYCOLYTIC FIBERS-FIBERS MAKE ATP ANAEROBICALLY (WITHOUT OXYGEN) VIA GLYCOLYSIS • SPEED OF CONTRACTION DEPENDS ON HOW QUICKLY A FIBER BREAKS DOWN ATP TO GAIN THE ENERGY NEEDED FOR CONTRACTION • SLOW OXIDATIVE FIBERS • FAST GLYCOLYTIC FIBERS • FAST OXIDATIVE FIBERS

Myofasical pain syndrome (from PP slide)

• PAIN CAUSED BY TIGHTENED BANDS OF MUSCLE FIBERS THAT TWITCH WHEN THE SKIN OVER THEM IS TOUCHED • SENSITIVE AREA OF SKIN IS CALLED TRIGGER POINTS • MOSTLY ASSOCIATED WITH OVER USED OR STRAINED POSTURAL MUSCLES AND THE PAIN IS OFTEN FELT SOME DISTANCE AWAY FROM THE TRIGGER POINTS, IN PREDICTABLE PLACES CALLED REFERENCE ZONES • VERY COMMON CONDITION AFFECTING UP TO HALF OF ALL PEOPLE MOSTLY THOSE FROM 30-60 YEARS OLD

Muscle Extension (from PP slide)

• SKELETAL MUSCLE AND ITS CONTAINED FIBERS ARE STRECHTED BY A MOVEMENT THAT IS OPPOSITE OF THE MOVEMENT THE MUSCLE NORMALLY PRODUCES. • I.E. A MUSCLE THAT NORMALLY ABDUCTS THE ARM AT THE SHOULDER IS STRECHED BY ADDUCTING THE ARM AT THE SHOULDER • WHEN A MUSCLE IS STRETCHED RATHER THAN CONTRACTED THE AMOUNT OF OVERLAP BETWEEN THE THICK AND THIN FILAMENTS DECREASES, THE I BAND AND H ZONES LENGTHEN AS THE Z DISC MOVE APART

Neuromuscular Junction Cont. (from PP slide)

• TERMINAL BOUTONS CONTAIN VESICLES THAT RELEASE NEUROTRANSMITTER WHEN A NERVE IMPULSE REACHES THE TERMINALS • THE NEUROTRANSMITTER AT THE NEUROMUSCULAR JUNCTION (ACETYCHOLINE) DIFFUSES ACROSS THE SYNAPTIC CLEFT AND BINDS TO RECEPTOR MOLECULES ON THE SARCOLEMMA WHERE IT INDUCES AN IMPULSE THAT INITIATES FIBER CONTRACTION

Neuromuscular Junction Unique Features (from PP slide)

• TERMINAL BOUTONS LIE IN A TROUGH LIKE DEPRESSION OF THE SARCOLEMMA • THE INVAGINATIONS OF THE SARCOLEMMA ARE COVERED WITH BASAL LAMINA • BASAL LAMINA CONTAINS THE ENXYME ACETYLCHOLINESTERASE WHICH BREAKS DOWN ACETYLCHOLINE IMMEDIATELY AFTER THE NEUROTRANSMITTER SIGNALS A SINGLE CONTRACTION • THIS ENSURES THAT EACH NERVE IMPULSE TO THE MUSCLE FIBER PRODUCES JUST ONE TWITCH OF THE FIBER

Fast Oxidative Fibers (from PP slide)

• THESE FIBERS ARE INTERMEDIATE IN MANY OF THEIR CHARACTERISTICS COMPARED TO THE OTHER TWO TYPES • CONTRACT QUICKLY • THEY ARE OXYGEN DEPENDANT • HAVE HIGH NUMBER OF MITOCHONDRIA AND RICH SUPPLY OF CAPILLARIES • FATIGUE RESISTANT BUT LESS RESISTANT THAN SLOW OXIDATIVE FIBERS • POWER OF CONTRACTION IS GOOD BUT NOT AS GOOD AS FAST GLYCOLYTIC • FIND THESE IN THE MUSCLES OF THE LOWER LIMB

Fast Glycolytic Fibers (from PP slide)

• THESE FIBERS ARE PALE DUE TO HAVING LITTLE MYOGLOBIN • TWICE THE DIAMETER OF SLOW OXIDATIVE FIBERS, CONTAIN MORE MYOFILAMENTS AND GENERATE MORE POWER • HAVE FEW MITOCHONDRIA AND CAPILLARIES DUE TO BEING ANAEROBIC TO MAKE ATP • HAVE MANY GLYCOSOMES CONTAINING GLYCOGEN (FUEL SOURCE) • CONTRACT RAPIDLY AND TIRE QUICKLY • FOUND IN MUSCLES OF THE UPPER LIMB

Types of Muscle Fibers (from PP slide)

• VARIOUS TYPES OF FIBERS THEY ARE CATEGORIZED BY TWO CHARACTERISTICS • HOW THEY MANUFACTURE ENERGY (ATP) • HOW QUICKLY THEY CONTRACT