Download Muscular System powerpoint

 Movement
(voluntary and
involuntary)
 Bodily functions
 There are THREE types of
muscle
Involuntary muscle that causes
movements within your body.
 Involuntary means “not consciously
controlled”
 Found in walls of esophagus and
intestines (help push food through
digestive system)
 Found in blood vessels, uterus, veins,
bladder, walls of stomach

Involuntary muscle that is found ONLY
IN THE HEART
 Allows your heart to beat and pump
blood throughout the body

Muscles that you control to move and
perform activities
 Skeletal muscles are attached to your
bones by tendons (a thick strand of
tissue that attaches a muscle to a
bone)






Contraction (becoming shorter and thicker)
Muscle fibers (muscle cells) contract when
they receive a nerve message to do so
Motor neurons control multiple muscle fibers
and receive the message to contract or relax
Your body recruits as many muscle fibers as
it needs
Have you ever started to drop something
because you thought it was lighter than it
was? Then what happened?




Similar to twizzles (reward prize, demonstrate
to show muscle)
Concentric contraction- contraction as the
muscle fibers shorten (Positive phase in
lifting, going against gravity)
Eccentric contraction-greater force lengthens
or elongates the muscle fibers as they
contract to DECELERATE (negative phase in
weight lifting, going with gravity)
Strength training is more effective when it
includes both types of contractions
Atrophy: weakening or shrinking of a
muscle (often due to lack of use)
 Hypertrophy: Enlarging of a muscle
 Muscle tone: Slight tension by a few
muscle fibers

Quadriceps
muscle
Hamstring