Transcript Structures of the muscular system

Muscular System
Objective 1.04
The Muscular System
• Comprises nearly half our weight.
• Over 650 muscles.
• Each muscle is made up of hundreds or
thousands of muscle fibers.
1.04 Remember the structures of
the muscular system
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The Muscular System:
Muscle Fibers
• Bundles of threadlike structures called myofibrils
– Composed of:
• Myosin
• Actin
– Form overlapping pattern called sarcomere
muscle
muscle fiber
sarcolemma
sarcomere
functional unit of muscle movement
1.04 Remember the structures of
the muscular system
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Structures of the muscular system
Muscles
Connective tissue
 Skeletal
 Tendons
 Smooth
 Fascia
 Cardiac
 Sphincter
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the muscular system
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Structures of the muscular system
Types of Muscle
Skeletal muscles
 Attached to bone
 Striated (striped) appearance
 Voluntary
 Multinucleated muscle cell bundles
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the muscular system
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Structures of the muscular system
Types of Muscle
Smooth muscles
 Also known as visceral muscles
 Involuntary
 Located in walls of digestive
system, uterus & blood vessels
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the muscular system
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Structures of the muscular system
Types of Muscle
Cardiac muscle




Found only in the heart
Striated, branched
Involuntary
Cells are fused- when one
contracts, they all contract,
creating the heartbeat
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the muscular system
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Structures of the muscular system
Types of Muscle
Sphincter muscles
 Also called dilator muscles
 Special, circular muscles
 Located in the
 digestive system
 urinary system
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the muscular system
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Structures of the muscular system
Types of Muscle
 Skeletal
 Smooth
 Cardiac
 Sphincter
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the muscular system
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Structures of the muscular system
Connective tissue
 Tendons
dense bands that connect skeletal muscle
to the bone
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the muscular system
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Structures of the muscular system
Connective tissue
 Fascia
Fibrous connective
tissue sheets that
wrap around muscle
bundles
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the muscular system
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How do skeletal muscles get
their names?
• Location of origin and
insertion
• Location
• Size
• Action flexor
• Direction
• Extensor
• Number of origins
• Depressor
• However, not all muscles are named by
the above methods!
1.04 Remember the structures of
the muscular system
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Head & Neck Muscles
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the muscular system
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Torso/Trunk
(anterior)
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the muscular system
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Torso/Trunk
(anterior)
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the muscular system
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Torso/Trunk
(posterior)
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the muscular system
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Upper extremities
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the muscular system
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Lower extremities
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the muscular system
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The muscular system review
Anterior view
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the muscular system
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The muscular system review
Posterior view
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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
1.05 Understand the functions and
disorders of the muscular system
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Characteristics of Muscles
Contractibility
Myoneural stimulation
+
contraction of muscle proteins
=
movement and heat
1.05 Understand the functions and
disorders of the muscular system
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Characteristics of Muscles
Excitability
1.05 Understand the functions and
disorders of the muscular system
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Characteristics of Muscles
Extensibility
1.05 Understand the functions and
disorders of the muscular system
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Characteristics of Muscles
Elasticity
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
1.05 Understand the functions and
disorders of the muscular system
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Characteristics of Muscles
Contractibility
Myoneural stimulation
+
contraction of muscle proteins
=
movement and heat (side effect)
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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Muscle Tone
Discuss muscle tone.
• Atrophy:
a- ________ -trophy _nourishment / development___
• Hypertrophy:
hyper- _______ -trophy _nourishment / development__
1.05 Understand the functions and
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?
1.05 Understand the functions and
disorders of the muscular system
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Muscle Fatigue
Discuss muscle fatigue:
– What causes muscle fatigue?
– How does the body correct muscle fatigue?
– Is muscle fatigue dangerous? Why / why not?
– Discuss aerobic and anaerobic exercise.
• Give examples of each.
1.05 Understand the functions and
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
As your muscle contracts,
one of the bones will
move with the other will
remain stationary.
Point of origin (end of the
muscle that is attached
to the stationary bone)
Point of insertion (end of
muscle that is attached
to the moving bone)
Prime mover or agonist
Antagonist – muscles
that cause movement in
the opposite direction
Synergists – assist
primary mover
All movement is a result of
contraction of primary movers
and relaxation of opposing
muscles.
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?
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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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Fibromyalgia
Discuss the pictures and how they relate to
fibromyalgia.
Cause - unknown
Symptoms – chronic pain, fatigue, depression
Diagnosis – location of pain
Treatment – symptom mgt
Prognosis – good…management
1.05 Understand the functions and
disorders of the muscular system
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Hernia
Weakness in the muscles of the
abdominal wall that allows loops of
intestine to balloon outward
Causes – muscle weakness, excessive
internal pressure
Locations – groin, abd
Symptoms – protrusion, pain
Diagnosis – palpation, mri
Treatment - surgery
Prevention – abd exercises
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Muscle Spasms
(Involuntary hypertonicity)
Symptoms – severe pain
Diagnosis – hx, physical exam
Treatment – rest, stretching, exercise
Prognosis - good
1.05 Understand the functions and
disorders of the muscular system
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Muscular Dystrophy
Cause – genetic defect…progressive weakness
and degeneration of skeletal muscle
Symptoms – muscle weakness, drooling, falling,
eyelid drooping (ptosis)
Diagnosis – physical exam, genetic test
Treatment – no treatment to stop or reverse
MD…treat symptoms
Prognosis - variable
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Myasthenia Gravis
Cause - Autoimmune attack at neuromuscular
junction…affects voluntary muscles…problem
with how nerves stimulate muscles to contract
Symptoms – progressive, fluctuating muscle
weakness and fatigue
Diagnosis – blood tests, EMG
Treatment – steroids, immunosuppressant
drugs
Prognosis – with treatment may lead a normal,
active life…remission possible
1.05 Understand the functions and
disorders of the muscular system
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Strain
• Overstretching of the tendons or the muscles
themselves (“pulled muscle”).
• Treatment = RICE
1.05 Understand the functions and
disorders of the muscular system
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Tendonitis
• Usually from chronic injury, overuse
•Pain and inflammation are common
• Treatment = (P)RICE
1.05 Understand the functions and
disorders of the muscular system
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Tetanus (Lockjaw)
Caused from a bacterial infection of clostridium
tetani usually after puncture wound.
Symptoms include progressive muscle spasms,
paralysis, stiffness and pain especially in jaw.
Diagnosis - physical exam, lab tests, history of
wound
Treatment – wound hygiene, tetanus vaccine,
pain management
Prognosis – without treatment 1 in 4 die…with
treatment less than 10% infected die
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