Muscle Physiology

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Muscle Physiology

• Summer Prematriculation Program
• Summer 2004
• Rahul Dave

Rdave2_at_uic.edu [phone] Rm 206 CMW
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Muscles act in many organ systems
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Muscles need a signal to contract
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Muscle Anatomy
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MotorUnit
Main Nerve
Nerve branch
Muscle
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SkeletalMuscle
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Smooth Muscle
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Cardiac Muscle 1
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Cardiac Muscle 2
Intercalated Disc
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3 Fiber Types
Fuel ATP Fatigues?
Fast White Glyc High Hard
Fast Red Oxid High Medium
Slow Red Oxid Low Easy
Motor Unit Size Recruitment Order Use
Fast White Large Third Power Lift
Fast Red Medium Second Jogging
Slow Red Small First Postural mm
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Sarcomere Structure
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Sliding Filament Theory
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Other Muscle Proteins
Brown Tropomyosin Yellow Troponins Blue Actin B
lack Myosin Head Bind Site
Pink Myosin
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Smooth Muscle Structure
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Muscle Structure

• Describe the hierarchy of organization in muscle
• Distinguish smooth, skeletal and cardiac muscle
  based on histology
• Understand and rationalize the differences
  between fiber types
• Know the skeletal muscle sarcomere structure cold.

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Nerve-MuscleInterface
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Excitation-Contraction Coupling
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Cross Bridge Cycle
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Smooth MuscleNerve-Muscle Interface
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E-C Coupling (Smooth)
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Crossbridge Cycle (Smooth)
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Muscle Contraction

• Know each step in transmission across the
  neuromuscular junction
• Know each step in E-C Coupling for striated
  muscle
• Know each step in the cross-bridge cycle for
  striated muscle
• Know the differences between smooth and striated
  (skeletal cardiac) muscle

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Preload and Afterload
Preload The force (load) a muscle exerts prior to
contraction. Pre-contraction Afterload Force
muscle exerts during contraction. After the
start of contraction
Demonstration
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Frank-Starling Law
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Force-Velocity Curve
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Exercise Physiology

• These are all adaptations
• Learning new motor patterns
• Strength exercises muscle hypertrophy
• Endurance exercises changes in muscle metabolism

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Muscle Diseases

• Metabolism
• Lactic Acidosis
• Glycogen Storage Diseases
• Muscle Function
• Dilated Cardiomyopathy
• Muscular Dystrophy
• Malignant Hyperthermia

• Neurologic
• Hirschsprungs disease
• Myesthenia Gravis
• Multiple Sclerosis
• Parkinsons Disease
• Polio