The
muscular
system
function
• Supports the
skeleton
• Aids in
movement
• Controls vital
processes such
as breathing and
heartbeat
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3 Different Muscle Types
• Skeletal Muscle
– Attaches to and moves bones
– Striated (striped) – alternating light and
dark bands
– Multiple nuclei in each cell
– Voluntary-under brain’s conscious
control
• Example: biceps
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• Smooth muscle
– Spindle-shaped cells
– One nucleus/cell
– No striations
– Controls breathing & digestion
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• Cardiac muscle
–
–
–
–
–
Striated
Cells smaller than striated muscle
1 or 2 nuclei/cell
Involuntary
Found only in the heart
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Muscle Fatigue
• If oxygen is not available muscle fatigue will set
in . Cells will start making energy by Anaerobic
Respiration without oxygen.
• Lactic Acid accumulates in the skeletal muscles
and causes a burning pain in the muscles.
• Rest restores the oxygen
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Muscle function
• Voluntary muscle
– Muscles that contract (move) only when you want them
to
– Examples: skeletal- biceps, abdominals
• Involuntary muscle
– Muscles contract (move) on their own
– Examples: cardiac, stomach, etc
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What connects our bones and our
muscles???
• Tendons
– Connects skeletal muscle to bones
– Ex. Achilles Tendon – connects gastrocnemius (calf)
to heel bone
• Ligaments
– Connects bone to bone
– Ex. ACL – Anterior Cruciate Ligament
connects femur to fibula
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Malfunctions:
• Strain
– Overstretching or tearing the muscle or tendon (can be
caused by improper lifting)
• Sprain
– Stretch or tear of ligament (at the joint) resulting from
sudden movement (ankle,wrists)
• “Pulled hamstring”
– Tear in a hamstring muscle
• Shin splint
– An inflammatory condition of the front part of the tibia
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Muscles
There are about 650-800 muscles in
your body with some conflicting
opinions because what experts
consider a muscle.
Smallest muscle in the ear- stapedius
Largest muscle –Gluteus Maximus
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