Muscular System 600 Muscles 1

Types of Muscle Movement Involuntary- Automatically move without you knowing. Voluntary- Brain sends message to muscle. You control the movements. 2

Types of Muscles Smooth Muscles- Which include the muscles of internal organs and blood vessels. These muscles move involuntary. Cardiac Muscle- Found only in the heart and also involuntary. Skeletal Muscles- Are voluntary and help you move. 3

Smooth Muscle Digestive organs Makes up 7-8% of your muscles Involuntary

Cardiac Muscles Only found in the heart. Involuntary. Makes up 3% of your muscles. By age 70 heart contracts 2.5 billion times (assume resting heart beat).

Skeletal Muscles Makes up 90% of your muscles. Voluntary- These are the muscles that you can move.

Types of Injuries Strain- Muscle “pull” or “strain” Tearing a muscle fiber(s), followed by bleeding or swelling of muscle Muscle Cramp- Prolonged contraction of muscle

Muscles and Movement Muscles can only contract & relax. Muscle fibers line up and pull the tendon attached to the bone to cause movement.

Muscle Pairs Muscle fibers line up and pull the tendon attached to the bone to cause movement. Your muscles work in teams to move your body. As one group of muscles is contracting another group is relaxing An example of this is your Bicep and Tricep.

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Systems Working Together Our brain sends a message The message travels down your spinal cord The motor neuron fires a message The muscle contracts. The muscle shortens pulling on the tendon The bone connected to the tendon moves