1. MUSCULAR
SYSTEM
MT H O B I S I
S HABANGU

2. INTRODUCTION
• The muscular system is composed of specialized
cells called muscle fibers.
• These fibers are different lengths and shapes and
form to become muscles.
• Muscles make up about 42% of a person’s total
body weight.
• Muscle fibers are held together by connective
tissue , enclosed in “fascia”.
• Muscles must have proper oxygen and nutrition to
function properly.

3. TYPES OF MUSCLE
TISSUE
Muscle Tissue
Skeletal
Voluntary
Satiated cells
Smooth
Involuntary
Blood vessels,
Urinary bladder,
Digestive system
Cardiac Muscle
Tissue
Found in the Heart
Striated and
Involuntary

4. TYPES OF MUSCLE
TISSUES CONT…
• Skeletal muscle
• Smooth Muscle
• Cardiac Muscle

5. Skeletal
Muscle
•
How many different
muscles can there
be?
•
~660

6. CHARACTERISTICS OF
MUSCLES of muscles to
• Contractility – the ability
shorten
•
Elasticity – the ability of muscles to go
back to its original shape
•
Excitability – the ability of muscles to
respond to stimuli
•
Extensibility – the ability of muscle to
lengthen
•
Sphincter – muscles that constrict
openings

7. CLASSIFICATION OF
MUSCLES
FUNCTIONALLY
• Voluntary – can be moved at
will
STRUCTURALLY
• Striated – have stripes across
the fibers
• Smooth – no striations
• Involuntary – can’t be moved
intentionally

8. CATEGORIES OF SKELETAL
MUSCLE ACTIONS
ACTIONS
CATEGORIES
• Extensor
• Flexor
• Abductor
• Adductor
• Levator
• Depressor
• Rotator
• Sphincter
•
•
•
Increases the angle at a joint
•
•
•
•
•
Moves limb toward midline of body
Decreases the angle at a joint
Moves limb away from midline of
body
Moves insertion upward
Moves insertion downward
Rotates a bone along its axis
Constricts an opening

9. NAMING SKELETAL
MUSCLES
Trapezius
• Shape:
• deltoid (triangle)
Deltoid
• trapezius (trapezoid, 2
parallel sides)
• serratus (saw-toothed)
• rhomboideus (rhomboid,
4 parallel sides)
• orbicularis and sphincters
(circular)
Serratus anterior
Rhomboideus
major

10. MUSCLES NAMED BY SIZE
• Maximus (largest)
• minims (smallest)
• Longus (longest)
• Brevis (short)
• Major (large)
• Minor (small)
Psoas minor
Psoas major

11. MUSCLES NAMED FOR
NUMBER OF ORIGINS
• Biceps (2)
Biceps brachii
• Triceps (3)
• Quadriceps (4)

12. MUSCLES NAMED FOR ACTION
• Flexor carpi radialis
(extensor carpi radialis)
– flexes wrist
• Abductor pollicis brevis
(adductor pollicis)
– flexes thumb
• Abductor magnus
– abducts thigh
• Extensor digitorum
– extends fingers
Adductor
magnus

13. COVERINGS OF SKELETAL MUSCLE
• Epimysium
• Connective tissue that covers the entire
muscle
• Lies deep to fascia
• Perimysium
• Surrounds organized bundles of muscle
fibers, called fascicles
• Endomysium
• Connective tissue that covers individual
muscle fibers (cells)

14. SARCOMERE
Now let us take a look at Sarcomere:
• A sarcomere is the functional unit of
skeletal muscle
•
A sarcomere is the area between
adjacent Z-lines.
• During a muscle contraction the z-lines
move together and the sarcomere
shortens.

15. Picture of a Sarcomere

16. Type I slow
fibers of
skeletal
muscle
Type II fast
fibers of
skeletal
muscle
Slow tonic
specially designed
for postural
muscles, red in
colour due to high
concentration of
myoglobin and rich
in mitochondria and
oxidative enzymes
Fast tonic
Varient of Type II
contractions needed
for body
movement, pale
colour rich in
glycogen and
phosphorylases
Highly resistance
to fatigue due to
well-developed in
aerobic respiration
Easily fatigue
Intermedia
te fibers of
skeletal
muscle
Resistant to fatigue
The types of
Fibers

17. THERE ARE ABOUT 60 MUSCLES IN
THE FACE.
Smiling is easier than
frowning.
It takes 20 muscles to smile and over 40 to frown.
Smile and make someone happy.

19. MACROSTRUCTURE
Skeletal muscle
c.s. 40x
It is the number of muscle
fibers packed into a given
muscle cross-sectional area
that determine overall
force-generating capacity

21. MICROSTRUCTURE
• basic functional unit of
muscle
• Striated (light & dark
bands)
• Contains ACTIN & MYOSIN
filaments that are
responsible for
contraction

22. REFERENCES
Dimapilis, H. 2014. Muscular System. www.slideshare.net/hansdimapilis/muscular-systemidsn
05/03/2014
Accessed
Agamez, M. 2011. An overview comparing the three different types of muscular tissue.
http://www.slideshare.net/monica_agamez/muscular-system. Accessed on the 05/03/2014
Marydelaney, L. 2009, Muscular System. http://www.slideshare.net/marydelaney/chapter-22-muscular-system.
Accessed 05/03/2014
By Itsebo, 2011. The muscular-system. http://www.slideshare.net/itsebo/the-muscularsystempowerpoint-drbantiles Accessed 05/03/2014
•
Cerny, L. 2009. Applied Excecise Physiology, Muscular Skeletal. http://www.slideshare.net/pcerny/muscularsystem Accessed 05/03/2014