Download Class Topics

5/24/2017
Title:
Anat & Phys
12/6/06
Objectives:
To learn about the physiology of muscles.
Class Topics
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Review contraction
Isometric contraction
Contraction graphs
Myosin isoforms
Test review
Biomechanics
“One cannot talk himself out of something he behaved himself
into.”
Anonymous
Wednesday, May 24, 2017 4:29 AM
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Class Assignments
What
• Muscle physiology test
By When
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 doesn’t relax
– not enough ATP to move calcium ions
back into SR
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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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Muscle Types
HO “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
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Connective tissues
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Organelles
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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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Drawing, labeling
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Mitochondrion, nucleus, ribosomes
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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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Pivot
Levers
Fi Force in
Fo Force out
Fi
Fi
Fo
2nd class
Fo 1st class
Fo
Fi
3rd class
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1st class lever
Triceps Brachii, also found in muscles of neck and head
Fi
Fo
Increases speed and overcomes resistance
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2nd Class Lever
Gastrocnemius
Fi
Fo
Used to overcome resistance, move large weights
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3rd Class Lever
Masseter and temporalis with the mandible, also the biceps brachii
F1
Fo
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
1 mm
Fo
3 mm
Fi
Fo = ?
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