1. Muscular System

2. Interesting Facts about Muscles
You have all the muscle fiber you will ever have at birth. Once damaged they can't be replaced.
Arnold Schwarzenegger has as many muscle fibers as you - They're just thicker!
There are more than 600 voluntary muscles in the body.
The strongest muscle of the body is a muscle used for chewing!
Your hand contains 20 different muscles.
Muscles account for approximately 40% of your body weight.
It takes 17 muscles in your face to smile, but it takes 43 muscles to frown.
You take approximately 5 million steps per year using your leg muscles!

3. 600
Did you know you have more than ______ muscles in your body? They do everything from pumping blood throughout your body to helping you lift your heavy backpack. You __________________ some of your muscles, while others do their jobs without you thinking about them at all.
control

4. TYPES OF MUSCLES

5. Smooth Muscles involuntary contract relax eyes internal
Sometimes also called ______________________. You can't control this type of muscle. Your brain and body tell these muscles what to do without you even thinking about it.
Smooth muscles are at work all over your body. In your stomach and digestive system, they ______________ (tighten up) and __________ to allow food to make its journey through the body. Your smooth muscles come in handy if you're sick and you need to throw up. 
You'll find smooth muscles at work in your ____________, too. These muscles keep things focused.
Smooth muscle is found in the walls of _____________ organs such as the stomach, esophagus, intestines, and in the walls of blood vessels.
contract
relax
eyes
internal

7. Cardiac Muscle
heart
The muscle that makes up the _____________ is called cardiac muscle. The thick muscles contract to ____________ _____________ out and then relax to let blood back in after it has circulated through the body.
Just like smooth muscle, cardiac muscle works all _____ _____________ itself with no help from you. 
pump blood
by itself

9. striated voluntary back
These are sometimes called _______________ muscle because the light and dark parts of the muscle fibers make them look striped.
Skeletal muscles are ________________ muscles, which means you can control what they do. Your leg won't bend to kick the soccer ball unless you want it to. 
They come in many different sizes and shapes to allow them to do many types of jobs.
Some of your biggest and most powerful muscles are in your _____________. These muscles help keep you upright and standing tall.
voluntary
back

13. Tendons and Ligaments… What’s the difference?

14. Tendons connect ________________________ to ________________
Tendons connect ________________________ to ________________. They are made of a tough, yet flexible, band of tissue.
Ligaments connect _____________________ to ___________________ to help stabilize joints. They are slightly elastic, so they can be stretched to increase flexibility.
muscle
bone
bone
bone

16. WHAT ARE THE JOINTS AND WHAT DO THEY DO?
Joints allow our bodies to move in many ways. Some joints open and close like a hinge, whereas others allow for more complicated movement.

17. There are several types of joints and they are classified by their range of movement. 
_________________ joints don't move.
The dome of the skull is made of bony plates, which must not move to protect the brain.
Immovable

18. Partially/slightly movable
________________________ _____________ joints slightly move. Each of the vertebrae in the spine moves in relation to the one above and below it; this allows the spine a small amount of movement.

19. Freely movable fluid Hinge Pivot Ball and socket
_____________ ________________ joints are the main joints in the body and move in many directions. Examples are found at the hip, shoulders, elbows, knees, wrists, and ankles.
They are filled with ____________, which acts as a lubricant to help the joints move easily. There are three kinds of freely movable joints that play a big part in voluntary movement:
_____________ joints allow movement in one direction, as seen in the knees and elbows.
_____________ joints allow a rotating or twisting motion, like that of the head moving from side to side.
__________________________ joints allow the greatest freedom of movement. The hips and shoulders have this type of joint, in which the round end of a long bone fits into the hollow of another bone.
fluid
Hinge
Pivot
Ball and socket