vizeletürítést

Vizeletürítés, also known as urination or micturition, is the process by which urine is expelled from the body. This physiological function is a critical component of the urinary system, responsible for eliminating waste products and excess fluid from the bloodstream. The process begins in the kidneys, where blood is filtered to produce urine. This urine then travels down the ureters to the bladder, a muscular organ that stores it.

When the bladder fills to a certain capacity, stretch receptors within its walls send signals to the brain, creating the sensation of needing to urinate. This triggers a complex reflex involving both voluntary and involuntary muscle contractions. The detrusor muscle in the bladder wall contracts, while the internal and external urethral sphincters, which control the flow of urine, relax. The external sphincter is under voluntary control, allowing individuals to consciously decide when and where to urinate.

The act of urination involves the coordinated effort of the nervous system, bladder muscles, and sphincter muscles. The frequency and volume of urination can vary significantly depending on factors such as fluid intake, diet, age, and certain medical conditions. Disorders affecting this process can range from urinary incontinence, an inability to control urination, to urinary retention, a difficulty in emptying the bladder. Understanding vizeletürítés is fundamental to comprehending kidney function and overall bodily fluid balance.