Download CH14_02 Muscular System

The muscular system enables the
limbs and other parts of the body to
move.
smooth muscles
skeletal muscles
flexor
extensor
cardiac muscle
tendinitis
hernia
What Muscles Do
The muscular system allows for voluntary
and involuntary movements.
Your muscular system allows you to move.
What Muscles Do
Involuntary muscle movements help you breathe,
make your heart beat, and move food through your
digestive system.
What Muscles Do
Skeletal muscles work
in pairs to produce
movement.
How Muscles Work
Muscles consist of long, fibrous cells that
can shorten and stretch to make muscles
move.
Major muscles in the body are made up of
hundreds of bundles of muscle fibers.
How Muscles Work
When bundles of muscles are stimulated by nerve
impulses, or signals, they contract, or shorten.
When they relax, the bundles extend, or stretch.
Types of Muscles
Three Types of Muscle Tissue
Smooth
Muscle
Skeletal
Muscle
Cardiac
Muscle
Types of Muscles
Smooth muscles are involuntary muscles.
Smooth muscles
Muscles that act on the lining of
the body’s passageways and
hollow internal organs
Types of Muscles
Most of your muscle tissue is skeletal, and almost
all skeletal muscles are under voluntary control.
Skeletal muscles
Muscles attached to bone that
cause body movements
Types of Muscles
When you bend and straighten your arm at the
elbow, the biceps is the flexor.
Flexor
The muscle that closes
a joint
Types of Muscles
When you bend and straighten your arm at the
elbow, the triceps is the extensor.
Extensor
The muscle that opens
a joint
Types of Muscles
Cardiac muscle is involuntary and is responsible
for the contraction of your heart. Your heart beats
100,000 times each day.
Cardiac muscle
A type of striated muscle that
forms the wall of the heart
Caring for Your Muscles
Eating a healthy diet and getting regular
exercise will help you care for your muscular
system.
Muscle tone is the natural tension in the fibers
of a muscle.
Caring for Your Muscles
Get regular exercise.
Eat high protein foods to build muscle.
Practice good posture to strengthen back muscles.
Use proper equipment and wear appropriate clothing to protect
muscles during any physical activity.
Warm up properly and stretch before exercising, and cool down
after exercising to prevent injury.
Caring for Your Muscles
Prepare your muscles
by stretching before
beginning a workout.
Understanding Muscular Problems
Caring for the muscular system can help
prevent health problems and injuries.
Recovery from muscle injuries varies according
to the type and severity of the injury or disease.
Understanding Muscular Problems
Bruises are areas of discolored skin that appear
after an injury that causes the blood vessels
beneath the skin to rupture and leak.
Large bruises can be treated with an ice pack to
reduce initial swelling.
Understanding Muscular Problems
Muscle strains or sprains result when muscles are
stretched or partially torn from overexertion.
Apply ice to strains to reduce swelling, and rest the
affected area.
Understanding Muscular Problems
Tendinitis can be caused by injury, overuse, or
natural aging.
Tendinitis
The inflammation of
a tendon
Understanding Muscular Problems
Hernias commonly occur in the abdomen from
straining to lift a heavy object. Surgery can usually
repair hernias.
Hernia
An organ or tissue
protrudes through an area
of weak muscle
Understanding Muscular Problems
Muscular dystrophy is an inherited disorder in
which skeletal muscle fibers are progressively
destroyed.
There is no cure, but with early detection, muscle
weakness can be delayed through exercise
programs.
After You Read
Reviewing Facts and Vocabulary
1. What are the functions of the muscular
system?
The muscular system allows for voluntary
and involuntary movements.
After You Read
Reviewing Facts and Vocabulary
2. Where is smooth muscle found?
Smooth muscle is found in the lining of the
body’s passageways and hollow internal
organs, such as in the digestive tract, the
urinary bladder, the lining of the blood
vessels, and passageways into the lungs.
After You Read
Reviewing Facts and Vocabulary
3. What is a hernia? How can you get one?
A hernia occurs when an organ or tissue
protrudes through an area of weak muscle.
A hernia in the abdomen can be caused by
straining to lift a heavy object.