Final answer:
Water constitutes about 50-70% of an adult's body weight and is distributed as intracellular and extracellular fluids throughout the body. It's essential for various bodily functions and found in differing proportions across tissues and organs.
Step-by-step explanation:
Water is a crucial component of the human body, making up about 50-70% of an adult's body weight. It is distributed throughout the body, playing various roles in its functioning. Within the body, water is found in intracellular fluids (within cells), comprising about 50% of the body weight in lean individuals, and extracellular fluids, which account for about 20% of body weight. This includes interstitial fluid, blood plasma, as well as cerebrospinal fluid (CSF), ocular fluid, lymph, and synovial fluids.
The distribution of water in the human body is not uniform; organs like the brain and kidneys are composed of 80-85% water, while bone and fat tissues have much lower water content. Additionally, blood plasma, which is more than half of blood by volume, is composed majorly of water and is essential for carrying various dissolved substances throughout the body.