1.05 Understand the
functions and disorders of
the muscular system
1.05 Understand the functions and
disorders of the
muscular system
• What are the characteristics of muscles?
• What are the functions of the muscular system?
• What are common disorders of the muscular
system?
• How are muscular disorders treated?
• How does the muscular system relate to the
body’s support and movement?
1.05 Understand the functions and
disorders of the muscular system
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Characteristics of Muscles
Contractibility
Excitability
Extensibility
Elasticity
1.05 Understand the functions and
disorders of the muscular system
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Characteristics of Muscles
Contractibility
• muscle shortens thus reducing the
distance between its parts (i.e.
cardiac muscle contraction reduces
area between blood chambers
causing heart to pump; skeletal
decreases distance between
attachment points allowing bone to
move)
1.05 Understand the functions and
disorders of the muscular system
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Characteristics of Muscles
1.05 Understand the functions and
disorders of the muscular system
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1.05 Understand the functions and
disorders of the muscular system
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Characteristics of Muscles
Contractibility
Neurotransmitter at site of
muscle stimulus.
The sodium-potassium
pump of the membrane of
a muscle cell.
The purpose of this slide is to
illustrate the complexity of the
process of movement.
1.05 Understand the functions and
disorders of the muscular system
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Skeletal Muscle Contraction
MYONEURAL STIMULATION
Neuron stimulates all skeletal muscles within a MOTOR UNIT (neuron & all
muscle fibers that it stimulates) neuron’s axon sends impulse by
releasing acetylcholine attaches to the sarcolemma (muscle cell
membrane) NEUROMUSCULAR JUNCTION allows the muscle fibers to
become temporarily permeable to Na+ ions which go rushing into the muscle
cells this excess of positive ions from the rush of sodium create the
electrical disturbance to allow muscle contraction
Contracting Muscle Proteins
Basic energy source is GLUCOSE in the form of ATP and Phosphocreatnine
(allows energy to be transferred to protein molecules in the muscle actin &
myosin) runs the entire length of the muscle releasing Ca++ ions that are
stored inside muscle cells that attach to muscle filaments  ATP energizes
these myofilaments to slide across each other allowing the muscle to shorten
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Characteristics
of
Muscles
Excitability- both
muscle and nerve
cells (neurons)
working together
Respond to different
stimuli by producing
electric signals
known as
ACTION
POTENTIALS
(impulses).
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disorders of the muscular system
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Characteristics of Muscles
Extensibility
• Ability to be
stretched
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disorders of the muscular system
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Characteristics of Muscles
Elasticity
Upon relaxing muscles
return to their original shape
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disorders of the muscular system
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Characteristics of Muscles
Contractibility
Excitability
Extensibility
Elasticity
1.05 Understand the functions and
disorders of the muscular system
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Muscle Tone
Discuss muscle tone.
• Atrophy:
a- _without_ -trophy :_development__
• Hypertrophy:
hyper- _excessive_ -trophy: _development__
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disorders of the muscular system
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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.
• What happened?
• How do you explain
this to him?
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disorders of the muscular system
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Muscle Tone
Exercise & Training
What are the
advantages of
exercise?
Are there any
disadvantages of
exercise?
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disorders of the muscular system
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Functions of the
Muscular System
What are the
functions of the
muscular system?
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disorders of the muscular system
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Movement:
Skeletal Muscle
• Receptors in muscles provide the brain with
information about body position and movement.
• The brain controls the contraction of skeletal
muscle.
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disorders of the muscular system
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Movement
Discuss the mechanism
of skeletal muscle
movement to include:
Point of origin
Point of insertion
Identify the:
Prime mover
Antagonist
Synergists
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disorders of the muscular system
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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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Movement:
Circulatory System
Heartbeat
The nervous system and hormones regulate the
speed at which the heart beats.
1.05 Understand the functions and
disorders of the muscular system
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Posture
• How does the muscular system effect
posture?
1.05 Understand the functions and
disorders of the muscular system
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Body Heat
What is the body’s response to cold? Why?
How is this response helpful?
How does the body respond to exercise? Why?
1.05 Understand the functions and
disorders of the muscular system
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1.05 Understand the functions and
disorders of the muscular system
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Muscle fatigue: decline in ability of a muscle to generate force
Correction of muscle fatigue:
• Nutrition – Maintain a well-balanced diet that includes complex proteins, fruits,
vegetables, and carbohydrates.
• Eating Schedule – Eat a light meal or snack about two hours before working out.
It is not recommended to work out on a full stomach or an empty stomach. Make
sure to eat within one hour after you work out. This will help repair and refuel the
muscles that were broken down during exercise.
• Hydration – Drinking water throughout the day and drinking sports drinks during
exercise is crucial to prevent dehydration, electrolyte loss, and muscle fatigue.
• Endurance – Improve your aerobic capacity. As your respiratory muscles begin to
fatigue, oxygen will be redirected from the muscles of your limbs to those of your
diaphragm
• Body Mechanics – Use correct form when exercising
• Rest/Recovery – Complete a warm up and cool down for 5 to 10 minutes each
time you exercise.
Anaerobic Exercise:
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disorders of the muscular system
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Aerobic Exercise:
Requires energy. When we exercise
aerobically our bodies use glycogen and
fat as fuel. This low to moderate level of
exertion can be sustained over long
periods. As you breathe more heavily with
exertion carbon dioxide is expelled from
your body. Lactic acid is not produced as it
is with anaerobic exercise.
Anaerobic exercise uses glycogen as well
which is usually depleted in 2 hours (i.e.
muscle fatigue). Your body builds up lactic
acid, which causes discomfort and fatigue
at sustained levels. For this reason
anaerobic exercise or high intensity
exercise happens in short bursts. It may be
helpful to consider the difference between a
sprinter (anaerobic) and a marathoner
(aerobic).
Benefits of Aerobic Exercise
Benefits of Anaerobic Exercise
It is difficult to overstate the benefits of
aerobic exercise. It not only improves
overall health and quality of life, but may
also extend your life. Aerobic exercise
burns fat, improves mood, strengthens the
heart and lungs and reduces your risk of
diabetes
Anaerobic exercise helps build lean muscle
mass. Calories are burned more efficiently
in bodies that have more muscle. Anaerobic
exercise is especially helpful for weight
management in that it helps to burn more
calories even in a body at rest. Anaerobic
exercise can also help build endurance and
fitness levels.
1.05 Understand the functions and
disorders of the muscular system
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1.05 Understand the functions and
disorders of the muscular system
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Fibromyalgia
Discuss the pictures and how they relate to
fibromyalgia.
Cause
Symptoms
Diagnosis
Treatment
Prognosis
1.05 Understand the functions and
disorders of the muscular system
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My- muscle
-algia: pain
Fibromyalgia
Chronic muscle pain lasting longer than 3 months
Symptoms:
•
•
•
•
Fatigue
Headache
Numbness/tingling
Joint pain
Treatment Goal:
Pain Relief
No Cure
Treatment Modalities:
Massage
Sleep/Rest
Chiropractor
Relaxation techniques
1.05 Understand the functions and
disorders of the muscular system
Stretching
Pain Meds
28
Hernia
Discuss hernias.
Causes
Locations
Symptoms
Diagnosis
Treatment
Prevention
1.05 Understand the functions and
disorders of the muscular system
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Hernia: organ protrusion out of a weak muscle
Types:
1. abdominal: organs protrude through the abdominal wall
2. Inguinal: organs protrude in the inguinal area
3. Hiatal: stomach pushes through the diaphragm
Causes:
Anything that exerts increased pressure in the abdomen
(overweight, carrying or pushing heavy objects, persistent coughing or
sneezing)
In addition, obesity, poor nutrition, and smoking, can all weaken muscles and
make hernias more likely
Treatment:
Surgical repair
1.05 Understand the functions and
disorders of the muscular system
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Muscle Spasms
(Involuntary hypertonicity)
Discuss muscle spasms.
Causes
Locations
Symptoms
Diagnosis
Treatment
Prognosis
1.05 Understand the functions and
disorders of the muscular system
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A muscle spasm, or muscle cramp, is an involuntary
contraction of a muscle. Muscle spasms occur
suddenly, usually resolve quickly, and are often painful.
Often due to dehydration or or overuse of the muscle.
Treatment:
Prevention is key. Drink plenty of fluids and stretch prior
to any strenuous activity or exercise. Once the spasm
occurs stretching it out will usually alleviate the
symptoms.
1.05 Understand the functions and
disorders of the muscular system
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Muscular Dystrophy
• Discuss the picture and how it relates to
muscular dystrophy.
Cause
Symptoms
Diagnosis
Treatment
Prognosis
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disorders of the muscular system
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Muscular dystrophy is a group of genetic diseases in which muscle fibers are
unusually susceptible to damage. These damaged muscles become progressively
weaker. Most people who have muscular dystrophy will eventually need to use a
wheelchair.
Duchenne muscular dystrophy
About half of all muscular dystrophy cases are the Duchenne variety, which most
commonly occurs in boys. Signs and symptoms typically first surface when the child
begins to walk and may include:
Frequent falls
Difficulty getting up from a lying or sitting position
Trouble running and jumping
Waddling gait
Large calf muscles
Learning disabilities
1.05 Understand the functions and
disorders of the muscular system
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1.05 Understand the functions and
disorders of the muscular system
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Myasthenia Gravis
Discuss the picture and how it relates to
myasthenia gravis.
Cause
Symptoms
Diagnosis
Treatment
Prognosis
1.05 Understand the functions and
disorders of the muscular system
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Autoimmune disease
Myasthenia gravis is caused by a breakdown in the normal communication between
nerves and muscles.
There is no cure
Symptoms: weakness of arm or leg muscles, double vision, drooping eyelids, and
difficulties with speech, chewing, swallowing and breathing.
Most common in women younger than 40 and in men older than 60.
Treatment:
Corticosteroids.
Immunosuppressants.
Plasmapheresis (plaz-muh-fuh-REE-sis). This procedure uses a filtering process
similar to dialysis. Your blood is routed through a machine that removes the antibodies
that block transmission of signals from your nerve endings to your muscles' receptor
sites
Intravenous immunoglobulin (IVIg). This therapy provides your body with normal
antibodies, which alters your immune system response.
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disorders of the muscular system
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Strain
•
•
•
•
What happened here?
What symptoms is this man having? Why?
How will he treat them?
What is his prognosis?
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A sprain is a stretching or tearing of ligaments — the tough bands of fibrous tissue that
connect one bone to another in your joints.
A strain is a stretching or tearing of muscle or tendon. A tendon is a fibrous cord of
tissue that connects muscles to bone.
Sprains
Pain
Swelling
Bruising
Limited ability to move the affected joint
At the time of injury, you may hear or feel a "pop" in your joint
Strains
Pain
Swelling
Muscle spasms
Limited ability to move the affected muscle
Medications: over-the-counter pain reliever such as ibuprofen (Advil, Motrin, others) or
acetaminophen (Tylenol, others).
Therapy: apply ice to the area as soon as possible to minimize swelling. In cases of
severe sprain or strain, your doctor may immobilize the area with a brace or splint.
Surgery. If you have a torn ligament or ruptured muscle, surgery may be an option.
1.05 Understand the functions and
disorders of the muscular system
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Tendonitis
Discuss the pictures and how they relate to
tendonitis.
Cause
Symptoms
Diagnosis
Treatment
Prognosis
1.05 Understand the functions and
disorders of the muscular system
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Tendinitis is inflammation or irritation of a tendon
If tendinitis is severe and leads to the rupture of a tendon, you may need surgical
repair. But most cases of tendinitis can be successfully treated with rest, physical
therapy and medications to reduce pain.
Symptoms:
Pain, often described as a dull ache, especially when moving the affected limb or joint
Tenderness
Mild swelling, possibly
Causes:
repetition of a particular movement over time
Treatment:
Corticosteroids
Pain relievers
Therapy program of specific exercise designed to stretch and strengthen the affected
muscle-tendon unit
1.05 Understand the functions and
disorders of the muscular system
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Tetanus
Discuss the picture and how it relates to
tetanus.
Cause
Symptoms
Diagnosis
Treatment
Prognosis
1.05 Understand the functions and
disorders of the muscular system
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Tetanus is a serious bacterial disease that affects your nervous system, leading to
painful muscle contractions, particularly of your jaw and neck muscles. Tetanus can
interfere with your ability to breathe and, ultimately, threaten your life. Tetanus is
commonly known as "lockjaw.“
There's no cure for tetanus. Treatment focuses on managing complications until the
effects of the tetanus toxin resolve. Fatality is highest in individuals who haven't been
immunized and in older adults with inadequate immunization.
Signs and symptoms of tetanus may appear anytime from a few days to several
weeks after tetanus bacteria enter your body through a wound. The average
incubation period is seven to eight days.
Common signs and symptoms of tetanus, in order of appearance, are:
•
•
•
•
•
•
•
•
•
Spasms and stiffness in your jaw muscles
Stiffness of your neck muscles
Difficulty swallowing
Stiffness of your abdominal muscles
Painful body spasms lasting for several minutes, typically triggered by minor
occurrences, such as a draft, loud noise, physical touch or light
Fever
Sweating
Elevated blood pressure
1.05 Understand the functions and
Rapid heart rate
disorders of the muscular system
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Causes:
The bacteria that cause tetanus, Clostridium tetani, are found in soil, dust and animal feces. It
enters the body generally through a flesh wound.
Treatment:
Since there's no cure for tetanus, treatment consists of wound care, medications to ease
symptoms and supportive care.
• Wound care
Cleaning the wound is essential to preventing growth of tetanus spores. This involves removing
dirt, foreign objects and dead tissue from the wound.
•
Medications
1. Antitoxin: Tetanus immune globulin. However, the antitoxin can neutralize only toxin
that hasn't yet bonded to nerve tissue.
2. Antibiotics: Either orally or by injection, to fight tetanus bacteria.
3. Vaccine: Having tetanus once doesn't make you immune to the bacteria afterward. So
you'll need to receive a tetanus vaccine in order to prevent future tetanus infection.
4. Sedatives: Use powerful sedatives to control muscle spasms.
5. Other medications: such as magnesium sulfate and certain beta blockers, may be
used to help regulate involuntary muscle activity, such as your heartbeat and breathing. Morphine
may be used for this purpose as well as sedation.
6. Supportive therapies: Tetanus infection often requires a long period of treatment in an
intensive care setting. Since sedatives may result in shallow breathing, you may need to be
supported temporarily by a ventilator.
1.05 Understand the functions and
disorders of the muscular system
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1.05 Understand the functions and
disorders of the
muscular system
• What are the characteristics of muscles?
• What are the functions of the muscular system?
• What are common disorders of the muscular
system?
• How are muscular disorders treated?
• How does the muscular system relate to the
body’s support and movement?
1.05 Understand the functions and
disorders of the muscular system
45