1. 1.05 Understand the characteristics of the Muscular System

2. 1.05 Understand the characteristics of the muscular system
What are the characteristics of muscles?
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3. Characteristics of Muscles
Contractibility
Excitability
Extensibility
Elasticity
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4. Characteristics of Muscles
Contractibility
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5. Characteristics of Muscles
Contractibility
Myoneural stimulation +
contraction of muscle proteins =
movement and heat
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6. 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.
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7. Characteristics of Muscles
Excitability - Irritability
The ability to respond to certain stimuli by producing impulses
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8. Characteristics of Muscles
Extensibility:
The ability to be stretched
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9. Characteristics of Muscles
Elasticity –
The ability of the muscle to return
to its original length when relaxing.
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10. 1.05 Understand the functions and disorders of the muscular system
video on how a muscle fiber contracts
CaOt6UQ
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11. Characteristics of Muscles
Contractibility
Excitability
Extensibility
Elasticity
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12. 1.05 Understand the functions and disorders of the muscular system
Muscle Tone
Muscle tone:
muscles is always slightly contracted and ready to pull
Atrophy:
a- without
-trophy development
Hypertrophy:
hyper- increased
-trophy development
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13. 1.05 Understand the functions and disorders of the muscular system
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?
Atrophy of unused muscle
How do you explain this to him?
Muscle tone
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14. Muscle Tone: Exercise & Training
What are the advantages of exercise?
Maintain muscle tone,
unused muscles atrophy
Are there any disadvantages of exercise?
Excessive exercise can lead to hypertrophy
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15. 1.05 Understand the functions and disorders of the muscular system
Muscle Fatigue
What causes muscle fatigue?
The buildup of lactic acid in the muscle during a period of vigorous exercise
How does the body correct muscle fatigue?
Increased respiration causing more oxygen to the muscles,
increased respiration continues until the oxygen debt is paid back.
Once the muscle returns to aerobic glucose use, respirations slow down.
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16. 1.05 Understand the functions and disorders of the muscular system
Muscle Fatigue
Is muscle fatigue dangerous? Why / why not?
Muscle fatigue can be dangerous if it turns in acidosis.
In a trained athlete not so dangerous, it can be dangerous to weekend warrior and leads to very sore and tender muscles
Some individuals are more prone to acidosis, such as a diabetic, and would want to be careful with muscle fatigue.
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17. Muscle Fatigue Aerobic versus anaerobic exercise.
Aerobic means using oxygen
Anaerobic means without oxygen
When exercising you use up a large portion of the oxygen in your body and the glucose in the cells can not be broken down for use fast enough.
So the muscle contracts anaerobically (without oxygen) which causes a buildup of lactic acid in the muscle and blood.
You are now in oxygen debt and will be until the amount of oxygen given to the cells is able to turn lactic acid back to glucose.
Muscle soreness is predominantly from lactic acid. 17

18. 1.05 Understand the characteristics of the muscular system
What are the characteristics of muscles?
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