The Muscular System

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The Muscular System

• Southern Boone County HS
• Dual Credit Anatomy
• Bill Palmer

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The Muscular System

• Muscles are organs
• There are more than 700 muscles in the human

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The Muscular System

• Four Properties of Muscle Tissue
• Excitability-very sensitive to input from nerves
• Contractility-cells contract
• Elasticity-ability to return to original shape
• Extensibility-cells must extend when opposite
  muscle contracts

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The Muscular System

• Five Functions of Skeletal Muscle Tissue
• Body Movement- Muscles work with the skeleton to
  provide movement
• Posture-muscles must contract to maintain posture
  
• Temperature Regulation-muscle contraction
  produces heat to keep body warm
• Storage of materials-sphincters (circular
  muscles) open and close to move material
• Support-protect and support organs (abdominal
  muscles)

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The Muscular System

• Each muscle is composed of a group of muscle
  fascicle
• Each fascicle is composed of a group of muscle
  fibers
• Muscle fibers are covered by three connective
  tissue layers
• Endomysium-inner layer
• Perimysium-middle layer
• Epimysium-outer layer

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The Muscular System
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The Muscular System

• Muscle Attachments
• Muscle fibers unite to form Tendons
• Most tendons cross at least one moveable joint
• Origin-fixed or less moveable end of muscle
• Insertion-more moveable end of muscle

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The Muscular System

• Tendonitis
• Inflammation of tendon or sheath surrounding
  tendon
• Caused by overuse of tendon
• Age, arthritis play a role
• Treatment
• Rest
• Ice
• NSAIDs
• Stretching and exercise help strengthen tendon
• Surgery

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The Muscular System

• Exercise and Skeletal Muscle
• Exercise builds muscle
• Muscle building requires diet, proper exercise
  routine, rest
• Lack of exercise cause muscle to atrophy (waste
  away)

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The Muscular System

• Hypertrophy-increase in muscle tone
• Exercise builds mitochondria, glycogen, and ATP
• More muscle fibers
• Hypotonia-decreased muscle tone, flaccid muscles,

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The Muscular System

• Anabolic Steroids
• Synthetic substances that mimic male
  testosterone-more than 100 are known
• Stimulate manufacture of muscle proteins
• Large doses needed
• Side effects include heart attack, kidney
  damage, aggressive behavior roid rage, tumors,
  testicular atrophy, acne, personality
  aberrations, man boobs

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The Muscular System
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The Muscular System
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The Muscular System
IS THIS REAL?
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The Muscular System

• Anabolic Steroids
• Women grow hair, menstrual problems, atrophy of
  uterus and breast.

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The Muscular System

• FOUR TYPES OF MUSCLES
• Circular muscle (sphincter)-arranged around an
  opening or recess (eye, mouth, anus)
• Convergent muscle-triangular muscle with a common
  attachment site (pectoralis major)
• Parallel muscle-long thin muscles (rectus
  adominis six-pack)
• Pennate muscle-one or more tendons (most muscles)

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The Muscular System
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The Muscular System

• Action of Skeletal Muscles
• Muscles work in pairs-three types
• 1) Agonist-contract to make a movement (triceps
  brachii agonist that causes extension)
• 2) Antagonist-oppose the agonist
• 3) Synergist-assist a prime mover

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The Muscular System

• Names of Muscles include clues to their ID
• Muscle action-Flexor carpi radialis
• Body region- Quadratis femoris
• Attachment- Sternocleidomastoid
• Orientation of fibers-Rectus abdominus
• Shape and size-Deltoid
• Origin-Biceps femoris

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The Muscular System

• Names of Muscles include clues to their ID
• Muscle action-Flexor carpi radialis
• Body region- Quadratis femoris
• Attachment- Sternocleidomastoid
• Orientation of fibers-Rectus abdominus
• Shape and size-Deltoid
• Origin-Biceps femoris

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The Muscular System
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The Muscular System

• General Muscle Types
• Skeletal Muscle-Voluntary long fibers, many
  nuclei, striated (biceps)
• Cardiac Muscle-Involuntary Short branched
  fibers, 1 or 2 central nuclei, striated (heart)
• Smooth Muscle- Involuntary Spindle shaped
  fibers, one central nucleus, no striations
  (intestines)

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The Muscular System
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The Muscular System

• Aging decreases the elasticity and diameter of
  muscle fibers. Ability to exercise decreases with
  age.
• Muscle system begins to develop during the fourth
  week.

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The Muscular System

• Neuromuscular Diseases
• Fibromyalgia-pain, stiffness, fatigue, depression
• Cause not known
• Affects 1-2 of population, mostly women
• TreatmentNSAIDs, exercise, reduce caffeine and
  smoking

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The Muscular System

• Neuromuscular Diseases
• Muscular Dystrophy-hereditary
• Skeletal muscles degenerate, lose strength
• Duchenne Muscular Dystrophy (DMD) most common
• affects males
• Most die by age 20

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The Muscular System

• Neuromuscular Diseases
• Myasthenia Gravis (MG)
• Affects 1 in 10,000 people (mostly women, 20-40
  years old)
• Antibodies attack muscle nerves
• Treat with drugs
• Variations in affects on life span

PTOSIS-Drooping of eyelid
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The Muscular System

• Neuromuscular Diseases
• Myofascial Pain Syndrome (MPS)
• Common-affects 50 of 30-60 year olds
• Associated with use of posture muscles
• Muscles tighten and twitch
• Treatment is NSAIDs, massage,

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The Muscular System- Wrap-ups

1. How many muscles are there in the human body?
2. What are the four properties of muscle tissue?
3. What are the five functions of the muscular
   system?
4. What are the three components of a muscle?
5. How are muscles attached?

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The Muscular System- Wrap-ups

• 6. What is the role of exercise in muscle
  development?
• 7. What are hypertrophy and hypotonia?
• 8. What are anabolic steroids? What are the side
  effects of using anabolic steroids?
• 9. What are the four types of muscles based on
  shape?
• 10. How are muscles named (6 ways)?

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The Muscular System- Wrap-ups

• 11. Name the three general muscle types and where
  each may be found.
• 12. When does the muscle system develop and how
  does aging affect muscles?
• 13. What is fibromyalgia? Symptoms? Treatment?
• 14. What is DMD? Symptoms? Treatment?
• 15. What is MG? Symptoms? Treatment?
• 16. What is MPS? Symptoms? Treatment?

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The Muscular System- Wrap-ups

• Complete labs 19-23
• Work on Muscle Poster Teams of four
• Due last day before Christmas Vacation