Transcript Muscles

By: Adam Lundquist, Carmela Patriz, DeCarlo Ward
“ROTATE, FLEX, EXTEND
THE MUSCULAR SYSTEM IS YOUR
FRIEND!”
The Major Functions of
the muscular system:
• Skeletal muscles contract which moves the body.
• Skeletal muscles also maintains a person’s posture.
• Production of body heat which is necessary for
homeostasis and maintaining a person’s body
temperature.
• Smooth muscles can move solids and liquids
through the digestive track and other secretions
from organs.
• Cardiac muscle makes the heart beat and propels
blood throughout the entire body.
C
Muscle Structures
Skeletal Muscle
Each muscle is an
organ, comprised of
skeletal muscle tissue,
several connective
tissue coverings,
nervous tissue that
causes it to contract
and blood that
nourishes it.
C
Connective Tissue Coverings:
• Epimysium- Under the • Fascia- Layers of fibrous
outer layer is this layer tissue that surround and
separate each muscle
which is around each
- This type of connective
whole muscle
tissue extends past the
• Perimysium- surrounds
ends of the muscle and
individual bundles of
gives rise to cord like
fibers called fascicles
tendons that are fused to
within each muscle
the periosteum of bones.
• Endomysium- is a
• Aponeurosis - Broad
fibrous connective tissue sheets of connective
layer that covers each tissue that are sometimes
connected to muscles
D
muscle cell (fiber)
Muscle Fiber(Cell)
‒ Each muscle fiber is covered by a connective
tissue layer called endomysium.
‒ Muscle fiber membrane is the sarcolemma
which contains cytoplasm called sarcoplasm.
‒ Within the sarcoplasm are many parallel
myofibrils.
‒ These protein filaments are actually made up of
two types; a thicker filament which is mysosin
and a thinner filament actin.
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Muscle Fiber(Cell)
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Relationships with the Neuromuscular
Junction
The neuromuscular junction is the site
where the motor neuron and muscle
fiber meet.
The muscle fiber membrane forms a
motor end plate in which the
sarcolemma is tightly folded and where
nuclei and mitochondria are abundant.
Acetylcholine is a neurotransmitter
released from the motor of the neuron.
Muscle innervation releases calcium.
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Sliding Filament Theory
‒Sarcomere shortens when ATP gives
energy to myosin because crossbridges of
thick filaments (myosin) pull on think
filaments (actin).
Steps:
•
•
•
•
•
Nerve impulse---acetylcholine is released
Muscle impulse
Calcium released--- (from sarcoplasmic reticulum)
Calcium binds to troponin, changing shape
Myosin heads attach to actin
• Heads pivot, shortening
• Sarcomere = Contract
A
Sources of Energy:
Existing ATP in molecule
Creatine Phosphate(converting
ADP+P to ATP)
Glycolysis (without oxygen)-lactic
acid
Cell Respiration (with oxygen)need blood supply (hemoglobin)
-interrupted=fatigue
Myoglobin in muscles stores
oxygen for cell respiration
ENERGY
A muscle cramp is an involuntarily
and forcibly contracted muscle that
does not relax.
A cramp can involve a part of a
muscle, the entire muscle, or even
several muscles that usually act
together.
A very common reason for cramping
is dehydration or low sodium.
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ENERGY(oxygen debt)
When oxygen debt gets to a certain point then
muscle fatigue occurs & too much lactic acid
builds up due to lack of oxygen
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Muscular Responses
Summation:
Recruitment:
This is when the force of
individual twitches
combines.
An increase in
the number of
motor units being
activated.
D
Muscular Responses
Sustained Contraction:
Muscle Tone:
‒ Summation and
‒ Even when a
recruitment
muscle appears
together can
produce a sustained to be at rest its
fibers undergo
contraction of
increasing strength. some sustained
contraction.
This is called
muscle tone.
D
Movements of Muscles
FLEXION
EX
EXENTION
PRONATION SUPINATION
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Movements of Muscles (cont.)
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Movements of Muscles (cont.)
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Diseases/Disorders
• This is a group of inherited disorders
& can occur in childhood or
adulthood and involve weakness in
muscles and the loss of muscle
tissues over a period of time that can
keep getting worse and worse.
• Some of the types of muscular
dystrophy are:
Becker muscular dystrophy
Duchenne muscular dystrophy
Limb-girdle muscular dystrophy,
Myotonia congenita
A
Myotonic dystrophy
Fibromyalgia:
Diseases/Disorders
• Fibromyalgia is a common
syndrome in which some
people can have bodywide pain and some
tenderness in their joints,
and in muscles, tendons,
and soft tissues.
• It has also been linked to
loss of sleep, fatigue,
depression and anxiety,
and headaches.
A
Myositis:
Diseases/Disorders
• This is the inflammation of your skeletal
muscles (called voluntary muscles)
• Injuries, infections or an autoimmune
disease can cause myositis.
Focal Myositis
Inflammatory Myopathy
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The End
ANY QUESTONS?
Works Cited
• Clencoe Hole’s Essentials of Human Anatomy & Phisiology
• Gretchen Fisher
• http://www.encognitive.com/node/1127