🫘 Kidneys and Urinary Tract: Your Child's Waste Removal System
Complete Guide to Understanding How the Kidneys Filter Waste and Maintain Fluid Balance in Children
What Are the Kidneys and Urinary Tract?
The urinary tract is one of the systems that our bodies use to get rid of waste products. The kidneys are the part of the urinary tract that makes urine (pee). Urine has salts, toxins, and water that need to be filtered out of the blood. After the kidneys make urine, it leaves the body using the rest of the urinary tract as a pathway.
🫘 Key Functions of the Kidneys
- •Filter Waste: Remove harmful substances and excess water from blood
- •Make Urine: Create urine to carry waste products out of the body
- •Regulate Blood Pressure: Control fluid balance and blood vessel function
- •Balance Electrolytes: Maintain proper levels of salts and minerals
- •Produce Hormones: Make hormones for red blood cell production and bone health
What Are the Parts of the Urinary Tract?
People usually have two kidneys, but can live a normal, healthy life with just one. The kidneys are under the ribcage in the back, one on each side. Each adult kidney is about the size of a fist.
🫘 Kidneys
Two bean-shaped organs that filter blood and make urine. Each kidney has an outer layer called the cortex, which contains filtering units, and a center part called the medulla(meh-DUH-luh) with fan-shaped structures called pyramids.
- • Filter waste products from blood
- • Make urine to carry waste away
- • Regulate blood pressure and electrolytes
- • Produce hormones for red blood cells
🔵 Bladder
An expandable, muscular sac in the lower abdomen that stores urine until it's passed (voided) from the body through the urethra. The bladder can expand and contract as needed.
- • Stores urine until ready to urinate
- • Expands as it fills with urine
- • Sends signals to brain when full
- • Contracts to push urine out
〰️ Ureters
Thin, tube-like structures that carry urine from the kidney to the bladder. There are two ureters — one draining each kidney. They use muscle contractions to move urine downward.
- • Carry urine from kidneys to bladder
- • Two tubes, one from each kidney
- • Use muscle contractions to move urine
- • Prevent urine from flowing backward
🔽 Urethra
A single tube-like structure that allows urine to exit the body from the bladder. The male urethra ends at the tip of the penis; the female urethra ends just above the vaginal opening.
- • Carries urine from bladder to outside
- • Different length in males vs. females
- • Controlled by sphincter muscles
- • Allows voluntary urination
How Do the Kidneys and Urinary Tract Work?
Blood travels to each kidney through the renal artery. The artery enters the kidney at the hilus (HY-luss), the indentation in middle of the kidney that gives it its bean shape. The artery then branches so blood can get to the nephrons (NEH-fronz) — 1 million tiny filtering units in each kidney that remove the harmful substances from the blood.
🔬 Nephron Function
Each nephron contains a filter called the glomerulus (gluh-MER-yuh-lus). The fluid that is filtered out from the blood then travels down a tiny tube-like structure called a tubule (TOO-byool).
- • 1 million nephrons in each kidney
- • Glomerulus filters blood
- • Tubule adjusts salt and water levels
- • Removes harmful substances
🔄 Urination Process
Pee leaves the kidneys and travels through the ureters to the bladder. The bladder expands as it fills. When the bladder is full, nerve endings in its wall send messages to the brain.
- • Bladder expands as it fills
- • Nerve signals sent to brain
- • Sphincter muscle relaxes
- • Urine exits through urethra
🔄 The Complete Process
Blood Filtration
Kidneys filter waste from blood
Urine Formation
Waste products form urine
Storage
Bladder stores urine
Elimination
Urine exits the body
What Do the Kidneys Do?
Kidneys have many jobs, from filtering blood and making urine to keeping bones healthy and making a hormone that controls the production of red blood cells. The kidneys also help regulate blood pressure, the level of salts in the blood, and the acid-base balance (the pH) of the blood.
🩸Blood Filtration
- • Remove waste products from blood
- • Filter excess water and salts
- • Remove toxins and harmful substances
- • Maintain proper blood composition
⚖️Balance Regulation
- • Regulate blood pressure
- • Balance electrolyte levels
- • Control acid-base balance (pH)
- • Maintain fluid balance
🧬Hormone Production
- • Make erythropoietin for red blood cells
- • Produce renin for blood pressure
- • Activate vitamin D for bone health
- • Support overall body function
What Can Help Keep the Kidneys and Urinary Tract Healthy?
To help keep your child's kidneys and urinary tract healthy, there are several important steps parents can take to support proper kidney function and prevent urinary tract problems.
🥗 Healthy Lifestyle
- • Encourage plenty of exercise: Physical activity supports kidney function
- • Offer a nutritious diet: Balanced meals with fruits, vegetables, and whole grains
- • Help your child stay hydrated: Drink plenty of water throughout the day
- • Go for regular medical checkups: Annual physical exams and screenings
- • Talk to the doctor before giving supplements: Ensure safety and appropriateness
🛡️ Prevention Tips
- • Teach proper hygiene: Wipe from front to back after using the bathroom
- • Avoid irritants: No bubble baths, scented soaps, or sitting in shampoo water
- • Wear cotton underwear: Allows proper air circulation
- • Change wet bathing suits promptly: Prevent moisture-related problems
- • Know family history: Inform doctor about kidney problems, diabetes, or high blood pressure
⚠️ Warning Signs to Watch For
Let the doctor know if your child has any of these symptoms:
- • Swelling or puffiness
- • Pain with peeing
- • Needs to pee often
- • Foamy urine
- • Blood in the urine
- • Constipation
⚠️Medical Disclaimer
The information provided on this page about the kidneys, urinary tract, kidney function, and related health topics is for educational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Every child is unique, and kidney or urinary concerns require individual assessment by qualified healthcare professionals.
Always consult with your child's pediatrician, nephrologist, urologist, or qualified healthcare provider if you have concerns about your child's kidney health, urinary function, or any related symptoms. For medical emergencies, call 911 or visit your nearest emergency room immediately. Content compiled from trusted pediatric health references and medically reviewed educational resources.