Okay kiddo, so you know when you go to the doctor and they check your ears, eyes and your heartbeat? They use special tools to help them do that. These tools are called instruments and doctors use them to help them see things that they can't with just their eyes.
One of the most common tools doctors use is a stethoscope. It's like a pair of headphones that the doctor puts in their ears, and it has a long tube with a round end that they place on your chest or back. The stethoscope helps the doctor hear your heartbeat and breathing sounds to check if everything is healthy.
Another important instrument is called an otoscope, which is a small flashlight with a magnifying glass attached to it. The doctor uses it to check inside your ears to see if there are any problems like infections or blockages.
The doctor might also use a blood pressure cuff, which goes around your arm and squeezes it tight for a few seconds. This helps the doctor to see how strong your heart is pumping blood through your body.
There are lots of other instruments that doctors use too, like reflex hammers to check your reflexes and thermometers to measure your temperature. All of these tools help the doctor to learn more about your body and how healthy you are, so they can help you feel better if you're not feeling well.