I can move because I have muscles. Muscles that help me move are fastened to my bones and are elastic, like rubber bands. They can stretch out and draw back together again. Some muscles, like the...
My body’s framework
I have a skeleton inside of me. That's what my bones are called. If I had no bones, I wouldn't be able to stand or bend or run or play. I'd be floppy like a rag doll. I have bones of many shapes and...
The me that I can’t see
When I look at a model of a human body, I can see what's inside my body. What does the inside of me look like? What's inside my finger, my head, my chest? I know many of the things that are in...
My fingernails and toenails
My fingernails and toenails are made up of hard skin cells. These cells are formed by the same protein that makes my hair strong. Animals' claws and hoofs are made of the same thing. My nails grow...
What is a cell ?
All living things---plants, animals, and people---are made of cells. I am made of cells. A cell is the smallest living part of me it is possible to imagine. A cell can be long, short, thin, fat,...
My body’s control center
My brain is the control center of my body. I have one brain. It is in my skull. My spinal cord is the path along which most messages move to and from my brain. I have one spinal cord. It is in my...
My kidneys and other organs
In my back, just below my ribs, on each side of my spine, are my kidneys. My kidneys are about half as big as my heart. They are shaped like beans. Kidneys do an important job for my body---they...
I eat food
I use my tongue and teeth when I eat. These help me grind up and mix my food. I use muscles, too, when I eat. I use muscles in my jaws, throat, esophagus, stomach, and intestines. Special organs...
My heart and blood
My heart is about as big as my fist. Each side of it works. The right side receives blood from the rest of my body. It pumps the blood to my lungs. In my lungs, blood takes oxygen from the air. The...
I breathe
I breathe in and out through my nose and mouth. Fresh air is made warm and clean in my nasal cavity. The air goes down my trachea, through my bronchial tubes, and deep into my two lungs. Used air...
