What Is Collagen? Collagen (KOL-uh-jin) is a protein in the body. Different types of collagen are in many body parts, including hair, skin, nails, bones, ligaments, tendons, cartilage, blood vessels, and intestines. What Does Collagen Do? Collagen has many different roles in the body. It: helps make bones strong lets the skin and tendons stretch helps with healing after …
What Is the Lymphatic System? The lymphatic system is part of the immune system. It keeps body fluid levels in balance and defends the body against infections. Lymphatic (lim-FAT-ik) vessels, tissues, organs, and glands work together to drain a watery fluid called lymph from throughout the body. What Does the Lymphatic System Do? One of the lymphatic system’s …
Skin, hair, and nails are made of similar types of cells. They form the outer layer of the body, called the integumentary (in-teh-gyoo-MEN-tah-ree) system. It protects everything inside the body. What Do Skin, Hair, and Nails Do? Skin, hair, and nails do many jobs. They: Block germs and dirt from getting inside the body and causing harm. Protect …
Skin, Hair, and Nails: The Body’s Protective Layer Read More »
What Is Skin? Skin is the body’s largest organ. Every inch of a person’s skin is made of millions of cells. Inside the skin are glands, nerve endings, and blood vessels. What Does Skin Do? Skin does many important jobs. It: protects the organs inside our bodies forms a barrier that prevents harmful substances and germs from …
What Is the Peripheral Nervous System? The peripheral nervous system is a network of nerves that runs throughout the head, neck, and body. It carries messages to and from the central nervous system (the brain and spinal cord). Together, the peripheral nervous system and the central nervous system form the nervous system. What Does the Peripheral Nervous System …
What Is the Nervous System? The nervous system includes the brain, spinal cord, and a complex network of nerves. This system sends messages back and forth between the brain and the body. The brain is what controls all the body’s functions. The spinal cord runs from the brain down through the back. It contains threadlike …
What Are Nails? Nails are plates of hardened protein packed into layers. Nails support and protect the sensitive tips of our fingers and toes. We use our nails for many tasks, like picking up small objects, scratching an itch, and untying a knot. What Are the Different Parts of Nails? Nails have many parts: The matrix (MAY-triks) …
Why Are the Mouth and Teeth Important? Every time we smile, frown, talk, or eat, we use our mouths and teeth. Our mouths and teeth let us make different facial expressions, form words, eat, drink, and begin the process of digestion. The mouth is essential for speech. With the lips and tongue, teeth help form words …
What Is Metabolism? Metabolism (meh-TAB-uh-liz-um) is the chemical reactions in the body’s cells that change food into energy. Our bodies need this energy to do everything from moving to thinking to growing. Specific proteins in the body control the chemical reactions of metabolism. Thousands of metabolic reactions happen at the same time — all regulated …
What Is Reproduction? Reproduction is the process by which organisms make more organisms like themselves. But even though the reproductive system is essential to keeping a species alive, unlike other body systems, it’s not essential to keeping an individual alive. In the human reproductive process, two kinds of sex cells, or gametes (GAH-meetz), are involved. The male …
