Muscles

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Muscles
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Function a. Muscles contract or
shorten b. Provide motility c. Move
substances through body- heart, blood
vessels digestion
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FUNCTIONS d. Muscle tone - maintains posture
keeps organs in place e. Muscles generate
heat when worked
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Types of muscles
1. Skeletal - Attached to bone a.
Voluntary b. Striated c. Multinuclei d.
Bundled cells e. Movement of body parts
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2. Smooth - internal organs
a. Involuntary b. Not striated c. Only 1 nucleus
per cell d. Regulates other systems
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Ex. Peristalsis moves food through digestive
system
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3. Cardiac - found only in heart
a. Striated b. Involuntary c. Can contract
without nervous stimluation
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d. Contracts relaxes continuously
Does not fatigue!
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Movement
1. Occurs when shortened 2. Work In pairs
a. Flexor - muscle that flexes bone
b. Extensor - muscle that
extends bone
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3. Tendons hold muscle to bone
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Sliding Filament Theory
Muscles made of 2 filaments (actin myosin)
that slide over one another when they contract.
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Sliding Filament Theory
Myosin
Actin
Relaxed
Contracted
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Caring for your muscles
1. Stretch before after exercise lactic acid
can build up and cause soreness possible
injury 2. Without adequate exercise, muscles
will atrophy.
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Caring for your muscles
3. Without proper nutrition, muscles may spasm
or become strained