Kidneys & How They Work
The kidneys are vital organs shaped like two beans, each approximately the size of a fist. They are positioned just below the rib cage, one on each side of the spine.
Function of the Kidneys
Healthy kidneys play a crucial role in filtering blood, removing wastes, and regulating the body's fluid balance. They filter about half a cup of blood every minute, producing urine which flows through the ureters to the bladder.
Components of the Urinary Tract
The kidneys, ureters, and bladder together form the urinary tract, responsible for storing and eliminating urine from the body.
Importance of Kidneys
Waste Removal: Kidneys eliminate wastes and excess fluids, maintaining a healthy internal environment.
Acid-Base Balance: They regulate the acid-base balance in the body, crucial for normal nerve and muscle function.
Mineral Regulation: Kidneys manage the balance of essential minerals like sodium, calcium, phosphorus, and potassium in the blood.
Hormonal Functions
Apart from filtration and regulation, kidneys produce hormones that:
- Control blood pressure.
- Stimulate red blood cell production (erythropoietin).
- Support bone health by activating vitamin D.
How Kidneys Work
Each kidney contains around a million nephrons, the functional units responsible for filtering blood and producing urine:
Glomerular Filtration: Blood enters the nephron's glomerulus, where small molecules and fluids pass into the tubule.
Tubular Reabsorption: The tubule reabsorbs essential substances like water, minerals, and nutrients back into the bloodstream, while excess wastes remain as urine.
Blood Circulation in the Kidneys
Blood enters the kidneys through the renal artery, is filtered by nephrons, and exits via the renal vein. This process occurs multiple times daily, filtering approximately 150 quarts of blood each day.
Urine Production
Most filtered substances are reabsorbed, with only 1 to 2 quarts of urine produced daily. Children produce less urine compared to adults, varying by age.
Clinical Trials and Research
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the NIH, conducts clinical trials to advance understanding and treatment of kidney diseases and related conditions.
Conclusion
Understanding the intricate functions of the kidneys is crucial for maintaining overall health and well-being. Proper kidney function ensures effective waste removal, fluid balance, and hormone production, contributing significantly to bodily functions and health maintenance.
