Body Basics

• Female Reproductive System

  The female reproductive system is made up of the parts inside and outside a female’s body that help make a baby. Learn about them and how they work.

• Hair

  Hair grows all over the human body except the palms of the hands, soles of the feet, and lips.

• Heart and Circulatory System

  The heart and circulatory system are our body’s lifeline, delivering blood to the body’s tissues..

• How Do the Ears Work? (Video)

  The ears gather sounds from our environment and turn them into messages for the brain to decode. Learn more in this video about the ears.

• Immune System

  The immune system, composed of special cells, proteins, tissues, and organs that protect against germs and microorganisms, is the body’s defense against disease.

• Kidneys and Urinary Tract

  The bean-shaped kidneys, each about the size of a child’s fist, are essential to our health. Their most important role is to filter blood and produce urine.

• Lungs and Respiratory System

  We need the respiratory system for breathing. Find out how it works.

• Male Reproductive System

  The male reproductive system is made up of the parts inside and outside a male’s body that help make a baby. Learn about them and how they work.

• Metabolism

  Brush up on metabolism, the chemical reactions in the body’s cells that change food into energy, in this article.

• Mouth and Teeth

  Our mouth and teeth play an important role in our daily lives. Here’s a course on the basics – including common problems of the mouth and teeth.