Review contraction

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Class Topics
Title Anat Phys 12/6/06
Objectives

• To learn about the physiology of muscles.

• Review contraction
• Isometric contraction
• Contraction graphs
• Myosin isoforms
• Test review
• Biomechanics
• One cannot talk himself out of something he
  behaved himself into.
• Anonymous

Tuesday, November 17, 2009 335 PM
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Class Assignments
By When
What

• Muscle physiology test 12/8/06
• Due this class period
• Due next class period
• Due in the future

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Anaerobic Respiration

• Oxygen debt
• oxygen goes toward decomposition of lactic acid -
  not respiration
• Muscle fatigue
• too much lactic acid - low pH - no contraction
• Muscle cramp
• muscle contracts but doesnt relax
• not enough ATP to move calcium ions back into SR

4
Muscle Tone

• Sustained contraction occurring in muscle fibers
  at all times - resting muscle
• Used for posture, body positioning, reflexes, and
  keep body firm
• Lost when a person passes out
• dead weight

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Rigor Mortis

• Contraction of muscle after death
• Sarcoplasmic Reticulum releases Calcium ions
• muscles contract, do not relax
• relax when decomposition occurs

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Isotonic

• Produces movement as the muscle pulls the bone
  toward a stationary structure
• ex. Bicep curl
• All movements!

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Isometric

• Produces muscle tensions, but the muscle does not
  shorten
• No body movement
• ex. Pushing an immovable object

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Twitch
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(No Transcript)
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Muscle TypesHO Muscle, Genes, and Athletic
Performance

• Slow twitch
• Type I
• Fast twitch
• Type IIe
• Type IIx

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Test Review

• No multiple choice
• All short answer, drawings, labeling, and essay
• Essay Explain muscle contraction and relaxation

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Test Review

• Connective tissues
• Drawing, labeling
• Organelles
• Mitochondrion, nucleus, ribosomes
• Neuromuscular junction
• All or none response
• Innervation
• Proteins
• Myofibril
• Energy sources
• Oxygen debt
• Muscle fatigue
• Muscle tone
• Muscle cramp
• Rigor mortis
• Isometric/isotonic
• Graphs twitch, summation, tetanic
• Myosin isoforms

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Biomechanics

• Skeletal system and muscular system working
  together
• Levers
• 3 types of levers
• 1st class
• 2nd class
• 3rd class

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Levers
Fi
Fi
Fo
Fo
2nd class
1st class
Fi
Fo
3rd class
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1st class leverTriceps Brachii, also found in
muscles of neck and head
Fi
Fo
Increases speed and overcomes resistance
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2nd Class LeverGastrocnemius
Fi
Fo
Used to overcome resistance, move large weights
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3rd Class LeverMasseter and temporalis with the
mandible, also the biceps brachii
Used to obtain rapid movement
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Mechanical Advantage

• Force out can be many times larger than force in
  by using the correct lever system
• Fo Fi (li/lo)
• li is the distance from Fi to the pivot
  (fulcrum), and lo is the distance from Fo to the
  pivot

Fi 160 dynes
3 mm
1 mm
Fo ?
Fi
Fo