Body Systems III

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Body Systems III

• The Muscular System

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Muscles

• There are about 600 muscles in the human body
• Voluntary Muscles- those that you can control
• Raising your hand, smiling
• Involuntary muscles- those that you cant control
• Breathing and digesting

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Types of Muscles

• There are three main types of muscle tissues in
  your body-
• Skeletal muscle
• Smooth muscle
• Cardiac muscle

Taken from Junqueira and Carneiro, Basic
Histology, a text and atlas, p. 191, Figure 10-1.
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Skeletal muscle

• These are the muscles that are attached to your
  skeleton and help you move
• Tendons are strong connective tissues that attach
  muscle to bone
• You can choose when you want to move parts of
  your body, so skeletal muscles are voluntary
  muscles

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Smoooth Muscle

• These muscles line the insides of many of the
  internal organs of your body, like the stomach.
• They are involuntary muscles that you have no
  control over.
• The processes they are involved in include
  digestion
• They do not tire as easily as skeletal muscles do

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Cardiac Muscle

• Cardiac muscle is involuntary and striated like
  skeletal muscle is but it doesnt get tired like
  skeletal muscle does
• It controls the beating of your heart again and
  again and ..

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Muscles at work

• Muscles do their work by contracting but they
  dont work alone-they work in pairs.
• The nervous system sends messages to the muscle
  cells telling them when to contract.
• Muscles cant extend only contract so while one
  contracts the other relaxes to its original
  length
• To bend your arm at the elbow, you must contract
  and relax your biceps and triceps at the same time

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How to get big muscles

• EXERCISE!
• The more you exercise the thicker your muscle
  gets, and the stronger it is