Muscular Control of Movement - Illinois Wesleyan University

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Transcript Muscular Control of Movement - Illinois Wesleyan University

Muscular Control of
Movement
Review of Anatomy
Types of Muscles
– Smooth: blood vessels and
organs
– Cardiac: heart
– Skeletal: muscles
for movement
Review of Anatomy
Skeletal
Muscle
– 600 Skeletal
Muscles
– Voluntary
Movement
– Origin /
Insertion
– 75% H2O,
20% Prot.
The Structure of
Skeletal Muscle
Epimysium
– Covers the entire muscle
Perimysium
– Covers the Fasciculi
Endomysium
– Covers the muscle fiber
Sarcoplasm
– Surrounds the myofibril
The Structure of a
Muscle Cell
Sarcoplasm
– Transverse Tubules
– Sarcoplasmic Reticulum
Myofibril
– Sarcomere
Myosin (heads)
Actin (tropomyosin, troponin)
The Sliding Filament
Theory
Motor nerve impulse
– motor nerve releases ACh to
sarcolemma
Depolorization causes chain
reaction
– sarcoplasmic reticulum
releases calcium
– calcium binds with troponin
– troponin lifts tropomyosin
– myosin heads bind with actin
(cross bridge)
Power Stroke: is the tilting of
the myosin head
The Sliding Filament
Theory
Energy is required for muscle
action
– the myosin head binds to ATP, and ATPase
found on the head splits ATP into ADP and P,
releasing energy for muscle contraction.
Calcium releases for muscle
relaxation
– calcium is pumped out of the sarcoplasm and
back into the sarcoplasmic reticulum for
storage, which requires ATP.
Slow Twitch vs Fast
Twitch
STo
slow ATPase
small SR
small motor
neuron
less fibers per
unit
aerobic
endurance
red color capillaries
B oxidation
enzymes
FTa, FTb, FTc
fast ATPase
large SR
large motor
neuron
more fibers
per unit
anaerobic
power
pink or white
in color
glycolytic
enzymes
Muscle Fiber
Recruitment
Motor units: consists of a single motor
neuron and all of the muscle fibers is supplies.
All-or-None Response:
Gradation of recruitment
– force production: is due to the number
of fibers recruited, not the force generated by
each fiber
– conditioning response: training
effects the coordination and recruitment of
muscles for specific activities
FTb & FTc fibers aren’t easily
recruited
Generation of Force
number of
motor unit
types of motor
units
size of the
muscle
muscles initial
length
angle of the
joint
muscle’s speed
stretch reflex
Use of Muscles
Types of
Movement
Types of
Contraction
– agonists
– concentric
– antagonists
– static
– synergists
– eccentric
Requirements For
Large Muscle
Development
Proper Nutrition
– 65% CHO, 20% Fat, 15%
Protein
Resistance Training
Genetics
Hormonal Secretion Levels
– testosterone
– androgens
ACSM Strength
Guidelines
Frequency = 2-3 days/week
Intensity
– 85% of max for strength
– 75% of max for muscular
power + (method)
– 50% - 65% of max for
muscular endurance
Time =
– 30 - 90 sec. per set / 8 - 12
reps per set
– work to rest ratio 1:4
Specificity = resistance type
Strength Training Myths
Strength training will cause “muscle
boundness”
Women who strength train will become
masculinized
Strength training reduces speed
“No pain - No gain”
It takes hours of daily training to gain
muscle mass
Food supplements will speed up
muscle development
Anabolic steroids are safe and
effective
Amino Acids are safe and effective
Types of Training
Isometric
Isotonic
Isokinetic
Plyometrics
Modes of Training
Free weights
Nautilus
Hydraulics
Friction
Rubber tubing
Cybex
Bow-flex
Box-jumps
Hydrotherapy
Etc.