Identify Body Organs and Systems

Your body is an incredible machine. Right now, without you even thinking about it, organs inside you are pumping blood, pulling in air, digesting food, and sending messages at lightning speed. An organ is a body part that does one main job to keep you alive and healthy.

The brain

• The brain sits inside your skull at the top of your body — it is protected by the hard bone of your head.
• It is the control center of your body. It receives messages from your senses and sends instructions to every other organ.
• The brain belongs to the nervous system.

The heart

• The heart is a muscle about the size of your fist, located slightly to the left in your chest.
• It pumps blood around your body, delivering oxygen and nutrients to every cell.
• The heart belongs to the circulatory system.

The lungs

• You have two lungs — one on each side of your chest. They look like two soft pink sponges.
• Every time you breathe in, your lungs fill with air and pull oxygen into your blood. Every time you breathe out, they push carbon dioxide back out.
• The lungs belong to the respiratory system.

The stomach

• The stomach sits in the upper left part of your belly. It is a stretchy bag made of muscle.
• It breaks down food using acid and muscle squeezing so nutrients can pass into your blood.
• The stomach belongs to the digestive system.

The bones

• All your bones together form the skeleton — 206 bones in a grown-up body.
• Bones give your body its shape, protect soft organs (your ribs protect your heart and lungs), and let you move.
• Bones belong to the skeletal system.