Section 11.2 Your Muscular System

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Objectives

Describe the functions of the three types of muscles.

Explain how you can keep your muscular system healthy.

Section 11.2 Your Muscular System

Define:Atrophy-Hypertrophy-Anabolic Steroids-

Section 11.2 Your Muscular System

Definitions:*Atrophy- A condition in which muscles that cannot contract

or are not used often weaken and shrink.

*Hypertrophy- An enlargement of the muscle tissue as a result from an increase in size rather than number of muscle cells.

*Anabolic Steroids- An artificial form of the male hormone testosterone that is used to increase muscle size and strength.

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Section 11.2 Your Muscular System

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• Muscles move your eyes as you read.

What do your Muscles do?

• Muscles in your chest allow you to breathe.

• Muscles in your heart pump your blood.

• Every time your body moves, muscles are at work.

Section 11.2 Your Muscular System

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3 types of muscles

Types of Muscle

• *Smooth muscle is involuntary muscle that causes movements within your body.

• *Cardiac muscle is involuntary muscle that is found only in the heart.

• *Skeletal muscles are the muscles that you control to do activities, such as walk or play a musical instrument. A thick strand of tissue called a tendon attaches a muscle to a bone.

Section 11.2 Your Muscular System

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3 types of muscles

Types of Muscle

Section 11.2 Your Muscular System

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Which type of muscle are the following? 1.

2.

3.

Section 11.2 Your Muscular System

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• *All muscles do work by contracting, or becoming shorter and thicker.

How Muscles Work

• *Many skeletal muscles work in pairs.

• *One muscle in the pair contracts to move the bone in one direction.

• *Then, the other muscle in the pair contracts to move the bone back.

Section 11.2 Your Muscular System

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Muscle Pairs

Biceps contracted

Biceps relaxed

Triceps relaxed

Triceps contracted

Section 11.2 Your Muscular System

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Section 11.2 Your Muscular System

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345

8

910

11

12

The Muscular System

3) Trapezius

4) Deltoid

5) Pectoralis major

8) Biceps

9) Triceps

10) External oblique

11) Rectus abdominus

12) Quadriceps muscles

Section 11.2 Your Muscular System

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• You can maintain a healthy muscular system by regularly participating in different types of exercise.

Keeping Healthy

Section 11.2 Your Muscular System

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• *Muscular Endurance is the amount of times a muscle can contract without getting tired.

• Examples: Bench pressing a light amount of weight many times. Hiking the pill boxes. Swimming to flat island.

• *Muscular Strength is the amount of force a muscle can generate 1 or 2 times.

• Examples: Bench pressing a heavy weight a few times. Jumping to block a volleyball. Pitching a baseball.

Working Your Muscles

• Other exercises make individual fibers grow, which causes the muscles to thicken and increase in strength.

Question: What is this process called?

Section 11.2 Your Muscular System

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Working Your Muscles

• Other exercises make individual fibers grow, which causes the muscles to thicken and increase in strength.

Question: What is this process called?

Section 11.2 Your Muscular System

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• A muscle cramp is a strong, uncontrolled muscle contraction.

Preventing Muscle Cramps

• To relieve a cramp, try stretching and massaging the affected area and exercising the limb gently.

• Drinking plenty of water before and during exercise can help you avoid muscle cramps.