What Do Your Kidneys Do?
Are you looking for an easy way to teach your child about the human body? We’ve put together a set of free materials that parents and teachers can use right away. In this lesson, your child will dive into the fascinating world of what the kidneys do.
We’ll explore the way your kidneys act as a filtering factory to create urine from blood. Explore science in a more engaging way with captivating 3D videos and interactive quizzes. Download our app to get started!
What You Will Learn From This Lesson
- Urine is made in the kidneys.
- Urine is made by filtering blood and reabsorbing nutrients and water.
How Do the Kidneys Filter Blood?
The kidneys are organs shaped like two big beans. They act as a filtering factory, which means their main job is to filter waste products from the blood to create urine. Each kidney contains over a million tiny, tubelike filtering units called nephrons.
The filtering process starts in a cluster of capillaries called the glomerulus, which looks like a ball of yarn. The capillaries have tiny gaps that allow water, waste products, and some nutrients from the blood to be filtered out. This filtered liquid collects inside a cup-shaped structure called the Bowman’s capsule.
How Is Urine Formed?
The liquid filtered into the Bowman’s capsule is called primary urine. Primary urine contains water and waste, but also some important nutrients that the body needs. This liquid is not quite finished—it’s one step away from becoming actual urine.
Next, the primary urine passes through the renal tubule, a tube connected to the Bowman’s capsule. The renal tubule is wrapped in capillaries. Here, the body reabsorbs the useful nutrients and most of the water back into the blood. What do your kidneys do with what’s left behind? The remaining liquid—waste products and excess water—becomes the final urine. This urine then travels through the ureters and is stored in the bladder until it is released through the urethra.
Fun Fact
- The two kidneys are shaped like beans and sit on both sides of your spine, just below your rib cage.
- Your kidneys are like filtering factories that clean the waste from your blood.
- In one day, your kidneys can filter all the blood in your body about 40 to 50 times.
Vocabulary
- Kidneys: The organs that filter waste products out of the blood to make urine.
- Nephrons: Tiny, tubelike parts inside the kidney that do the actual filtering.
- Glomerulus: A cluster of capillaries inside the Bowman’s capsule where the first step of blood filtering happens.
- Bowman’s Capsule: A round part of the nephron that collects the filtered liquid, called primary urine.
- Primary Urine: The liquid collected in the Bowman’s capsule after blood is first filtered. It contains water, waste, and some nutrients.