Water H2O PDF

- Water H₂O - Tasteless, clear, odorless fluid. - Humans can survive for 4 - 6 weeks without food, but for only a few days without water. - Biological importance of water: - Water is the principal chemical (about 65% of the body weight in an adult male, 55% in females). - It is the universal...

- Water H₂O - Tasteless, clear, odorless fluid. - Humans can survive for 4 - 6 weeks without food, but for only a few days without water. - Biological importance of water: - Water is the principal chemical (about 65% of the body weight in an adult male, 55% in females). - It is the universal solvent in the body. - It is the principal constituent of all body fluids ("blood, lymph, tissue fluid"). - It is the transporting agent of the body. - Water is the main constituent of the excretory fluid "urine". - The daily needs of water depend on the water losses. Water losses are affected by the amount of physical exercise, the environmental temperature and humidity, and the condition of the subject. 1|Page - The recommended daily intake is about 2500 mL - 3000 mL/day for males. - Water losses or output occur through the following: - Urine = 750 - 1500 mL/day. - Perspiration, sweating, water vapor in expired air = 500 - 800 mL/day. - Insensible fluid losses as they cannot be easily measured. - Water supply occurs through the following: 1. Ingestion of fluids (drinking) = 1200 mL/day. 2. Ingestion of goods = 1000 mL/day. 3. Metabolic water = 250 mL/day. 2|Page