Download Muscular System - Junction Hill C

• Muscles that
attach to bones
and the
connective tissue
that attaches
them make up the
muscular system.
Types of Muscle
• Smooth Muscle
– Found in the digestive tract
and the blood vessels
• Cardiac muscle
– Special type of muscle
found only in your heart
• Skeletal muscles
– Attached to your bones for
movement, and they help
protect your inner organs
Skeletal Muscle
Cardiac Muscle
Smooth Muscle
• Muscle action can be voluntary or
involuntary
• Muscle action that is under your control is
voluntary
• Muscle action that is not under your
control is involuntary
• Smooth muscle and cardiac muscle are
involuntary
• Skeletal muscles can be both voluntary
and involuntary
– You can blink your eyes any time you
want to, but your eyes will also blink
automatically if you do not think about
it.
• When you want to make
a movement, you cause
electrical signals to travel
from the brain to the
skeletal muscle cells.
• The muscle cells respond
to these signals by
contracting or getting
shorter.
It takes an average of
13 muscles to smile
and an average of 43
muscles to frown
• Strands of tough
connective tissue
called tendons
connect your
skeletal muscles
to your bones
• Many basic movements are
the result of muscle pairs that
cause bending and
straightening.
• If a muscle bends part of your
body, then that muscle is
called a flexor
• If the muscle straightens part
of your body, then it is called
an extensor
• Skeletal muscles,
such as the biceps
and triceps muscles,
work in pairs.
• When the biceps
muscle contracts,
the elbow bends.
• When the triceps
muscle contracts,
the elbow
straightens
• When muscles are not
exercised, they become
smaller and weaker
• When muscles are
exercised, they
contract allowing blood
vessels in that muscle to
get squeezed. This helps push blood
along, increasing blood flow without
demanding more work from the heart.
Resistance Exercises
• To develop the size
and strength of your
skeletal muscles,
resistance exercises
are the most effective
form of exercise.
• Resistance exercises
require muscles to
overcome the
resistance of another
object.
Aerobic Exercise
• Aerobic Exercise
increases the size
and strength of your
skeletal muscles
somewhat, but
mostly it strengthens
the heart while
increasing the
endurance of your
skeletal muscles.
A muscle strain, commonly called a pulled
muscle, is the overstretching or
even tearing of a muscle.
Muscle strain often occurs
because the muscle has
not been properly
conditioned for the work
A damaged tendon can become hot or inflamed
as your body tries to repair it. This painful
condition is called tendinitis, and an extended
period of rest is often required for the tendon to
heal.
Dangers of Anabolic Steroids
• Some people try to make their
muscles larger and stronger by
taking hormones called anabolic
steroids.
• Anabolic steroids are powerful
chemicals that resemble
testosterone, a male sex
hormone.
• The use of anabolic steroids
threatens the heart, liver, and
kidneys, and it can cause high
blood pressure