weight and work skeletal muscle
DESCRIPTION
Weight and Work Skeletal Muscle. Definitions. Motor Unit : a motor neuron and all muscle fibers it innervates. Twitch : single contraction in response to a single stimulus/AP. Isotonic : muscular contraction where constant tension continues while the length of the muscle changes. Concentric - PowerPoint PPT PresentationTRANSCRIPT
Weight and WorkSkeletal Muscle
Definitions• Motor Unit: a motor neuron and all muscle fibers it
innervates.• Twitch: single contraction in response to a single
stimulus/AP.• Isotonic: muscular contraction where constant
tension continues while the length of the muscle changes. – Concentric– Eccentric
• Isometric: muscular contraction against resistance in which the length of the muscle remains the same.
Isotonic Contraction
Isometric Contraction
Work• Work is accomplished only when an object is moved.• Work = Force X Distance• Force = muscle tension required to overcome the
load (weight of the object).• In an isometric contraction where no object is
moved (muscles do not change length) the work done = zero.
Load/Velocity relationship
• Load is an important determinant of shortening velocity. Load = velocity
Load/Velocity Relationship
3 Muscle Fiber TypesSlow Oxidative
Fast Oxidative Fast Glycolytic
Postural muscles
Bird flight muscles
Mammal breast muscles
Lithobates pipiens• Referred to as Rana pipiens
also.• Opportunistic feeders• Occurs through much of US
and Canada (cosmopolitan)• Status is controversial:
widespread, but most populations throughout range are decreasing rapidly.
• Commonly used in research.
HOMEWORK!!!!• Write an entire lab report, again. • Include answers to ALL labscribe
questions WITHIN the body of the paper.
• Follow my formatting instructions!!!!!!
• Due on November 28/29.
Next Week…• Have a GREAT Thanksgiving!!!