Final answer:
After a night of heavy drinking, one's urine output will be mostly water because alcohol inhibits the release of antidiuretic hormone (ADH), leading to less water reabsorption in the kidneys and more dilute urine.
Step-by-step explanation:
After drinking too much alcohol, the urine output is mostly water, as alcohol inhibits the release of antidiuretic hormone (ADH). Alcohol's diuretic effect is due to its interference with the pituitary gland's secretion of ADH, which normally helps the kidneys reabsorb water and concentrate urine. Without adequate ADH, the collecting ducts in the kidneys become less permeable to water, leading to a decrease in water reabsorption and an increase in urine production.
This increased urine production can quickly fill the bladder, prompting the need to urinate. Diuresis, or the production of urine in excess of normal levels, typically begins about 30 minutes after consuming a large quantity of fluid. Peak urine production often occurs around one hour after drinking and returns to normal after about three hours.
The increased urine volume that results from ADH inhibition consists mainly of water, which can lead to the urine being more dilute and pale in color. Drinking alcoholic beverages can temporarily affect the excretory system's ability to concentrate urine. However, chronic excessive alcohol consumption poses serious long-term risks to organs such as the liver and kidneys, which are critical components of the excretory system.