A presentation on how muscles work in the body.

1. MUSCLES IN THE HUMAN BODY.

2. MUSCLES.
• There are 640 muscles in the average male body.
• All of this muscle weight accumulates to 2/5 of the individuals overall weight.
• There two muscle groups, flexor and extender.
The biceps are
flexors and the
triceps are
extenders.

3. TYPES OF MUSCLES.
• There are three types of muscles in the body. Skeletal
• Skeletal muscles control voluntary actions in the body.
• Smooth muscles control involuntary actions.
• Cardiac muscles control your heart.
Smooth
Cardiac

4. MUSCLES IN THE FACE.
• The muscles in the face are very complicated to allow you to be able to make the many
facial expressions that you can.
• They intertwine and over lap to move your jaw in the many directions that it can be.

5. MUSCLE CONTRACTION.
• Muscles can be both contracted and relaxed in different positions.
• They are attached to the bone by tendons which are made of collagen.
• In a fully relaxed muscle the muscle fibers do not overlap at all.
Stretched Partly contracted Fully contracted.

6. MUSCLE FIBERS
• Muscle fibers make up muscles.
• Muscle fibers are 1 ½ cm long and 1/500 cm in diameter.
• When muscles are contracted the fibers get shorter and wider

7. JOINTS
• All muscles move bones which revolve around a joint.
• A joint is generally where a muscle comes to an end and where to or more bones meet.

8. A COUPLE VIDEOS
• http://www.youtube.com/watch?v=CepeYFvqmk4
• http://www.youtube.com/watch?v=EhfFpKwQJLY