1. Lesson 7.7 Muscle Strength/Weakness
Keeping muscle healthy is
important because injury results in
reduced muscle strength.

2. Hypertrophy - enlargement of
a muscle through use.
Atrophy – the degeneration of
muscle due to lack of use.

3. All muscles contain
mitochondria (energy) and
myoglobin (oxygen).
Myoglobin gives meat its
red color.

4. Types of Muscle fibers
A. Red muscle fibers
Contains lots of
mitochondria and myoglobin.
Contraction is slow
known as slow-twitch fibers
Has great endurance
(marathon runner) (chicken
legs)

5. Types of Muscle fibers
A. Red muscle fibers
B. White muscle fibers
 fewer mitochondria and
myoglobin
Contract quickly called
fast-twitch fibers.
fatigue quickly because
fewer mitochondria
(sprinter) (chicken breast)

6. •Most muscles are a
combination of both red
and white.
•Red used mostly but if
need rapid and forceful
movement the white are
stimulated.

7. Can train your muscles
according to whether you
want
strength, endurance, or
speed.
Important to warm you
muscles up and cool them
down.

8. Muscle strains
when you tear a tendon due to
over work
usually heals fine

9. Muscle fatigue
when muscle becomes stiff, sore
and difficult to contract
occurs do to excessive use
occurs because of anaerobic
respiration and lactic acid build up

10. Muscle cramps
sudden and painful involuntary
contraction of muscle
Possibly resulting from ATP
storage

11. Muscle Tone
is a state of slight muscle
contraction even when at rest
keeps muscles from sagging and
ready for action

12. Note: The muscular, skeletal
and nervous system all
function together to make
motion possible.
A Divine Design!!!