1. Why don’t skeletons play music in church?
They have no organs

2. What does a skeleton order at a restaurant? Spare ribs

4. The Muscular System – 32.3

5. Essential Questions What are the three types of muscle tissue?
What are the events involved in muscle contraction at the cellular and molecular levels?
What are the differences between slow-twitch and fast-twitch muscle fibers?
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The Muscular System

6. The Muscular System
The ability to move is an essential activity of the human body
½ our body weight comes from muscles
Consists of over 600 individual muscles.
3 purposes:
Body movement
Body shape
Body heat (maintain temp.)

7. The Muscular System
Body movements are determined by three types of muscles
Smooth (involuntary) – cannot be controlled by will.
Cardiac – control the contractions of the heart.
Skeletal (Voluntary) – can be controlled by will.

8. Three Types of Muscle
Muscles are classified according to their structure and function.
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The Muscular System

9. Three Types of Muscle Smooth Muscle involuntary muscle Not striated
Not under conscious control
Not striated
Many hollow internal organs such as the stomach, blood vessels, intestines, bladder, and uterus are lined with smooth muscle.
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The Muscular System

10. Three Types of Muscle Cardiac Muscle Involuntary muscle. Striated
Fibers are arranged in a network that allows the heart muscle to contract efficiently and rhythmically.
Walls of heart
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The Muscular System

11. Three Types of Muscle Skeletal Muscle tough band connective tissue
voluntary muscles that cause movement.
striated
attached to bones by tendons.
tough band connective tissue
when tightened they contract, they cause movement.
muscles connected to bones
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The Muscular System

14. skeletal

15. Cardiac

16. Smooth

17. How Do Muscles Move the Body
Muscle Movement and Types
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The Muscular System

18. Skeletal Muscle Contraction
Skeletal muscle is arranged into fibers consisting of smaller units called Myofibrils.
Myofibrils c
consist of even smaller units:
Myosin
Actin
Arranged in sections called sacromere
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The Muscular System

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The Muscular System

20. Skeletal Muscle Contraction Sliding Filament Theory
Once a nerve signal reaches a muscle, the actin filaments slide toward one another, causing the muscle to contract.
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The Muscular System

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The Muscular System

22. Skeletal Muscle Contraction
Most skeletal muscles are arranged in opposing, or antagonistic pairs.
Flexion Extension
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The Muscular System

23. Types of Muscular Contractions
eccentric – lengthening contraction
concentric – shortening contraction
isometric – muscle contracts but does not change length (Demonstration)
9-24

24. They contain myoglobin
Skeletal Muscle Strength
Slow-twitch muscles
Slow-twitch muscle fibers have more endurance than fast-twitch muscle fibers.
They contain myoglobin
respiratory molecule that stores oxygen and serves as an oxygen reserve.
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The Muscular System

25. Skeletal Muscle Strength Fast-Twitch Muscles fatigue easily
provide great strength for rapid, short movements.
rely on anaerobic metabolism, which causes a buildup of lactic acid.
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The Muscular System

26. Textbook page 950 Data Analysis Lab 1

27. Muscle Review Basics

28. Identify Muscles Holes Anatomy Book pages 195-208