You have many miles of these throughout your body that gather information for your brain to use.

A doctor or nurse listens to your heartbeat using this instrument.

The short breathing tube, or windpipe, that leads to the lungs.

This is the strongest and larges bone in your body.

These kinds of muscles are attached to bones and allow us to move, bend, and twist.

Your brain cells are very sensitive to this gas and without it, they will begin to die.

You have 60,000 miles of these tubes to carry blood to and from all parts of your body.

These tubes branch off from the trachea and lead into each lung.

The knee, elbo, jaw, hips and ankles are just a few examples of where these are located.

These kinds of muscles control the movement of organs and blood vessels.

This part of your brain attaches to the spinal cord and is responsible for keeping your heart beating and your lungs breathing.

These blood bessels carry oxygen-rich blood from the heart to all parts of the body.

This strong muscle helps move air in and out of the lungs.

These strong bands of tissue connect bone to bone.

Muscles that function automatically, without our having to think about it, are called this.

This is the largest part of your brain, and it is responsible for your intelligence.

These blood bessels carry blood back to the heart and lungs to receive oxygen.

Millions of th ese tiny air sacs are located inside the lungs.

This strong, flexible material covers the ends of your bones so that they can slip smoothly past one another.

This is the approximate number of skeletal muscles in the human body.

This part of your brain is responsible for your coordination and balance. It is latin for "little brain."

These are very thin blood vessels in which the exchange of oxygen and food takes place.

This flap of tissue covers the trachea when you swallow so that food does not enter the lungs.

This jelly-like substance is found in the center of some long bones and helps make new red blood cells.

You were about this old in the womb when your cardiac muscle, or heart, started beating.