Download Muscular System Notes

Muscular System
• Did you know you have more than 600
muscles in your body?
• They help you do almost everything —
from pumping blood throughout your
body to lifting heavy weights.
• You control some of your muscles and
others, like your heart, do their jobs
without you thinking about them at all.
• Muscles are all made of the same material,
a type of elastic tissue (sort of like the
material in a rubber band).
• Thousands, or even tens of thousands, of
small fibers make up each muscle. You have
three different types of muscles in your
body:
– smooth muscle
– cardiac muscle
– skeletal muscle.
Smooth Muscle
• On the lining of passageways and
internal organs.
– Blood vessels
– Digestive tract
– Passageways that lead to the lungs and
bladder
• Involuntary control
Skeletal Muscle
• Attached to bone and cause body
movements
• Striated, or striped, appearance
• Skeletal muscle makes up most of
muscle tissue
• Almost all is voluntary
Skeletal Muscle
• Skeletal muscles often work together,
undergoing opposing actions
– One muscle contracts as another extends
• Bicep and tricep
• Flexor- the muscle that closes the joint
(bicep)
• Extensor- the muscle that opens the
joint (tricep)
Cardiac Muscle
• A type of striated muscle that forms
the wall of the heart.
• Involuntary
• Responsible for the contraction of the
heart.
• The heart contracts rhythmically about
100,000 times each day to pump blood
throughout your body.
Care of the Muscular System
• Regular physical activity
• Muscles that remain unused for long
periods of time will atrophy.
– Atrophy- decrease in size and strength
• Muscle tone
– The natural tension in the fibers of the
muscle
Problems with the Muscular
System
• Bruise
– This happens when blood vessels under the
skin rupture and leak.
Problems with the Muscular
System
• Muscle strain or sprain
– A strained muscle usually occurs when a
muscle is stretched or partially torn as a
result of overexertion.
– A sprain is an injury to the ligament in a
joint, and it requires medical treatment.
Problems with the Muscular
System
• Tendonitis
– Inflammation of a tendon
– Caused by:
• Injury
• Overuse
• Natural aging
– Signs
• Swelling
• Pain
• Swelling that worsens with activity
Problems with the Muscular
System
• Hernia
– When an organ or tissue protrudes through
an area of weak muscle.
– Results from straining to lift a heavy
object
– Usually requires surgery
Problems with the Muscular
System
• Muscular Dystrophy
– An inherited disorder in which skeletal
muscle fibers are progressively destroyed.
– No cure
– With early detection muscle weakness can
be delayed through exercise programs.