urinatsiooni

Urinatsiooni, also known as urination or micturition, is the process by which urine is expelled from the body. It is a fundamental physiological function essential for maintaining fluid balance and removing metabolic waste products. The process involves the urinary system, primarily the kidneys, ureters, bladder, and urethra.

The kidneys filter waste products and excess water from the blood, producing 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, sensory receptors signal the brain, creating the urge to urinate.

The act of urination is a complex interplay between voluntary and involuntary muscle control. The internal urethral sphincter, an involuntary muscle, relaxes, while the external urethral sphincter, a voluntary muscle, is consciously relaxed to allow the flow of urine through the urethra and out of the body.

Several factors can influence the frequency and volume of urination, including fluid intake, diet, medications, and underlying medical conditions. Issues with urination, such as difficulty initiating the flow, incontinence, or increased frequency, can indicate a health problem and may require medical attention.