Download Muscular System

Muscular System
This is what
happens without
muscles
“The power system”

#One Function
Responsible
for all body
movement.

#Two Function
 Responsible
for body form
and shape
(Posture)

#Three Function
 Responsible
for body heat
and
maintaining
body
temperature.
Test Your Gray Matter….

Muscles are responsible for producing
most of our : White blood cells,
Hormones, Protein synthesis, or Body
Heat.
Types of Muscles
Skeletal
Muscle
Smooth
Muscle
Cardiac
Muscle
Attached to
bone
Visceral
muscle
Found only
in the heart
Voluntary
Involuntary
Involuntary
Skeletal Muscles
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Attached to bone
Striated (striped)
appearance
Voluntary
Sarcolemma = cell
membrane
Contract quickly, fatigue
easily, can’t maintain
contraction for a long
period of time
Test your skeletal muscles…

Open and close your
dominant hand until
the teacher tells you
to stop.
Smooth Muscle
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Visceral (organ) muscle
Found in the walls of digestive
system, uterus, and blood
vessels
Cells small and spindle shaped
Involuntary – ANS Controlled
Act slowly, do not tire easily,
can remain contracted for a
long time.
Cardiac Muscle
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Found in heart
Striated and branched
Involuntary
Cells are fused, when
one contracts, they all
contract (HB)
Test your gray matter..
Which of the following Which kind of muscle
muscles are
forms the walls of the
considered “voluntary” heart?
Striated,
cardiac, skeletal,
visceral
Cardiac, Skeletal,
Smooth, Visceral
Sphincter

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Special circular
muscles in openings
of esophagus and
stomach, and small
intestine, anus,
urethra and mouth
AKA: dilator muscles
Characteristics of Muscles
Contractibility
Excitability
Extensibility
1.05 Understand the functions and
disorders of the muscular system
Elasticity
Muscle Characteristics

Contractibility
The ability of a muscle to
reduce the distance
between the parts of its
content or the space it
surrounds.
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Excitability
The ability to respond to
certain stimuli by producing
impulses.
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Extensibility
The ability to be stretched.
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Elasticity
Ability of muscle to return to
its original length when
relaxing.
Muscular system structures
Connective tissue
 Tendons
dense bands that connect skeletal muscle
to the bone
1.04 Remember the structures of the
muscular system
17
Structures of the muscular
system
Connective tissue
 Fascia
Fibrous connective
tissue sheets that
wrap around muscle
bundles
1.04 Remember the structures of the
muscular system
18
Sources of heat / energy
For muscles to contract and do their work they
need energy

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ATP – adenosine triphosphate – a major source
of energy found in the muscle cell.
When muscle is stimulated, ATP is released,
which produces heat and energy to contract
muscle.
Lactic acid – a by-product of cell metabolism
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Muscle
Movement
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Muscle moves bones by
pulling on them.
As a muscle contracts, it
pulls the Insertion one
closer to the Origin bone.
Movement occurs at the
joint between the origin
and the insertion.
Rule: A muscle’s insertion
bone moves toward its origin
bone.

Groups of muscles usually contract to produce a
single movement
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Prime mover
muscle whose
contraction is mainly
responsible for
producing a given
movement
 Antagonist
muscle whose actions
oppose the action of
prime mover in any
given movement.
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Synergist
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helps steady a
movement and
stabilize joint activity.
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When the antagonist muscles contract, they
produce a movement opposite to that of the
prime movers.
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Motor Unit – a motor neuron plus
all the muscle fibers it stimulates.
Neuromuscular Junction – the
junction between the motor
neuron’s fiber which transmits the
impulse – and the muscle cell
membrane.
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Muscle chemical
neurotransmitter, diffuses
across the synaptic cleft
(carries impulse across
synaptic cleft)
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Acetylcholine
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Fatigue
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caused by the
accumulation of lactic
acid in the muscles
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Oxygen Debt

after exercise, the
amount of oxygen needed
by the muscle to change
lactic acid back to
glucose.
Movement: Skeletal Muscle
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Receptors in muscles provide the brain with
information about body position and
movement.
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The brain controls the contraction of
skeletal muscle.
1.05 Understand the functions and
disorders of the muscular system
26
Movement: Digestive System
The nervous system regulates the speed at
which food moves through the digestive tract.
1.05 Understand the functions and
disorders of the muscular system
27
Exercise and training
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Will affect the size, structure and strength
of a muscle.
If injured, muscles can only regenerate a
limited degree.
If severe injury, muscle tissue may be
replaced with scar (connective) tissue.
Benefits of exercising
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Improved muscle coordination
Improved respiratory and circulatory
system to supply needs of an active
muscular system
Eliminate or reduce excessive fat.
Improve joint movement.
Increase muscle size
Atrophy vs
hypertrophy
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Atrophy –wasting
away of a muscle
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Hypertrophy –
growth of a
muscle due to
repetitive usage
Muscle Tone
John just got a cast off
his leg. His calf muscle
on the affected leg is 1”
smaller in diameter than
his other calf muscle.
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What happened?
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How do you explain
this to him?
1.05 Understand the functions and
disorders of the muscular system
31
Head & Neck Muscles
1.04 Remember the structures of the
muscular system
34
Torso/Trunk
(anterior)
1.04 Remember the structures of the
muscular system
35
Torso/Trunk
(anterior)
1.04 Remember the structures of the
muscular system
36
Torso/Trunk
(posterior)
1.04 Remember the structures of the
muscular system
37
Upper extremities
1.04 Remember the structures of the
muscular system
38
Lower extremities
1.04 Remember the structures of the
muscular system
39
Musculoskeletal disorders - Strain
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a tear of the muscle resulting
from excessive use
Pain and swelling occur due
to bleeding in the muscle
Ice packs will help reduce
swelling and stop bleeding
Rest and OTC medicines also
help.
Muscle spasm
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a sustained contraction of the muscle.
Occurs from over usage.
Myalgia
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muscle pain
Fibromyalgia
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chronic disease that includes muscle pain
lasting for 3 or more months
S/S: HA, fatigue, numbness, tingling, and
joint pain
Tx – rest, exercise, medicines,
chiropractic services, and massage.
Movement:
Digestive System
The nervous system regulates the speed at which
food moves through the digestive tract.
1.05 Understand the functions and
disorders of the muscular system
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Hernia
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occurs when an organ
protrudes through a weak
muscle.
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Abdominal
Inguinal
Hiatal – occurs when the
stomach pushes through the
diaphragm.
Tetanus (lockjaw)
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infectious disease that causes continuous
spasms of the voluntary muscles
Caused by toxin from the bacillus:
clostridium tetani
enters the body through a wound
Can be prevented by vaccine.
Muscular dystrophy
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muscle cells deteriorate
most common is Duchenne’s MD:usually
genetic defect
Usually death occurs in late teens or early
20’s.
Myasthenia gravis
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muscle weakness and paralysis
cause unknown: possible immune system
defect.
TENDONITIS
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inflammation of
a tendon