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Muscular SystemMuscular System

Muscles for LocomotionMuscles for Locomotion

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EngageEngage

Tennis Ball Muscle ActivityTennis Ball Muscle Activity

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ExploreExplore

Chicken Wing DissectionChicken Wing Dissection

The major function of the muscular The major function of the muscular system is to support our body in system is to support our body in movement. Through observations movement. Through observations and class discussion, you will make and class discussion, you will make deduction about certain principles of deduction about certain principles of muscle function. muscle function.

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ExploreExplore

““Multitalented Muscles” Multitalented Muscles”

Web SearchWeb Search

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ExplainExplain

What are some functions of the What are some functions of the Muscular System?Muscular System?

Contract and relax to move the body.Contract and relax to move the body.

Stores energyStores energy

Protects internal organsProtects internal organs

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Two Muscle CategoriesTwo Muscle Categories

InvoluntaryInvoluntary– NOT under conscious controlNOT under conscious control

VoluntaryVoluntary– Under conscious controlUnder conscious control

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Think About It!!Think About It!!

Can you think of one body function Can you think of one body function that you perform without thinking that you perform without thinking about it?about it?– Breathing, Heart Beating, Digestion, Breathing, Heart Beating, Digestion,

etc… etc…

How about one that one must think How about one that one must think about?about?– Picking up a pencil, walking, running, Picking up a pencil, walking, running,

etc… etc…

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Three Types of MusclesThree Types of MusclesSmooth MuscleSmooth Muscle

Cardiac MuscleCardiac Muscle

Skeletal MuscleSkeletal Muscle

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Smooth MuscleSmooth MuscleWhereWhere lining lining of Internal of Internal Organs and Organs and Blood VesselsBlood VesselsInvoluntaryInvoluntaryNon striated Non striated FunctionFunction Squeeze, exert Squeeze, exert pressure by pressure by slow and slow and prolonged prolonged contractionscontractions

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Cardiac MuscleCardiac Muscle

WhereWhere Heart Heart

InvoluntaryInvoluntary

Striated Striated and and branchedbranched

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Skeletal MuscleSkeletal MuscleMajority of Majority of muscle in the muscle in the bodybodyVoluntaryVoluntaryStriatedStriatedFound Found attached to attached to the skeleton the skeleton by TENDONS.by TENDONS.

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QuestionsQuestions

What are the two categories of What are the two categories of muscles?muscles?

What are the three types of muscles?What are the three types of muscles?

Muscle that contract under conscious Muscle that contract under conscious control are _________.control are _________.

______ attaches muscle to bone.______ attaches muscle to bone.

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Skeletal Muscle StructureSkeletal Muscle Structure

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Skeletal Muscle StructureSkeletal Muscle Structure

MuscleMuscle - made of bundles - made of bundles

Bundles-Bundles- many muscle fibers many muscle fibers

Muscle Fiber – Muscle Fiber – many myofibrilsmany myofibrils

MyofibrilsMyofibrils- filaments (thick or thin)- filaments (thick or thin)

Thick filamentsThick filaments –myosin protein –myosin protein

Thin filamentsThin filaments –actin protein –actin protein

Thick and Thin give striated lookThick and Thin give striated look

Skeletal Muscle StructureSkeletal Muscle Structure

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Functional Unit of MuscleFunctional Unit of Muscle

SarcomereSarcomere– Section of myofibrilSection of myofibril

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Muscle ContractionsMuscle Contractions

Actin pulledCross-bridge releases actin

Cross-bridge changes shape

Myosin returns to original

shape

Myosin forms cross-bridge

with actin

2

1

34

5

Cycle Diagram

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Muscle ContractionsMuscle Contractions

Actin pulledCross-bridge releases actic

Cross-bridge changes shape

Myosin returns to original

shape

Myosin forms cross-bridge

with actin

2

1

34

5

Cycle Diagram

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Muscle Attachment to BoneMuscle Attachment to Bone

Muscles attached to bone by Muscles attached to bone by tendonstendons..

Muscles are attached in opposing Muscles are attached in opposing pairs.pairs.

One Muscle contracts to raise the One Muscle contracts to raise the limb, while the second will contract limb, while the second will contract to lower it.to lower it.

Bicep / TricepsBicep / Triceps

Movement Movement

Biceps (relaxed)

Triceps (contracted)

Biceps (contracted)

Triceps (relaxed)

Figure 36-11 Opposing Muscle Pairs

Section 36-2

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Muscle Strength and ExerciseMuscle Strength and Exercise

Strength DOES NOT depend upon the Strength DOES NOT depend upon the number of fibers. Why?number of fibers. Why?

Born with all fibers we will have.Born with all fibers we will have.

Depends on the THICKNESS of fibers Depends on the THICKNESS of fibers and how many contract at one timeand how many contract at one time

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Muscle Soreness After ExerciseMuscle Soreness After ExerciseDo muscle cells need ODo muscle cells need O22??– Yes!!!Yes!!!

Do muscle cells need ATP?Do muscle cells need ATP?– Yes!!!Yes!!!

Working out moderately provides us enough Working out moderately provides us enough oxygen (aerobic) to change glucose into ATPoxygen (aerobic) to change glucose into ATP– Called _________ respirationCalled _________ respiration

Working out rigorously does not allow us to get Working out rigorously does not allow us to get enough Oenough O22 in our blood. What happens with no O in our blood. What happens with no O22 (anaerobic)?(anaerobic)?Lactic Acid FermentationLactic Acid FermentationLactic Acid builds up in muscle cells passes into Lactic Acid builds up in muscle cells passes into the blood stream, causes the blood to become the blood stream, causes the blood to become acidic, stimulates breathing, and can cause acidic, stimulates breathing, and can cause crampingcramping

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Regular ExerciseRegular Exercise

Improves functioning of musclesImproves functioning of muscles

Aerobic training can affect a muscle’s Aerobic training can affect a muscle’s ability to share and use energyability to share and use energy

Increases endurance and thickness Increases endurance and thickness of muscle filaments (strength)of muscle filaments (strength)

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ElaborationElaborationThe Universe WithinThe Universe WithinWatch the coordination of several different Watch the coordination of several different body systems and how they make Mike body systems and how they make Mike Powell the world’s greatest long jumper.Powell the world’s greatest long jumper.Muscle Builders! Muscle Builders! Using various materials, you will build a Using various materials, you will build a model that simulates muscle contractions model that simulates muscle contractions and relaxations. This model depicts one and relaxations. This model depicts one muscle working in isolation, but as we muscle working in isolation, but as we have learned, muscles in the body have learned, muscles in the body cooperate in a group effort, like in the cooperate in a group effort, like in the chicken wing. chicken wing.