Water in organism
From WikiLectures
Water in organism is divided into:
- Free water – used to dissolve substances.
- Hydration water - bounded to hydrophilic colloids.
- Molecules of free and hydration water are constantly exchanged and in balance.
- Oxidising water – is formed during the burning of fats, proteins,...
A person can go without water for 6-8 days, then he loses more than 11% of water from muscle or fat tissue and die.
Water metabolism[edit | edit source]
Water metabolism in the body is very closely linked to Na⁺ metabolism . The ability of the organism to store water and divide it into the appropriate compartments is determined by the amount of particles dissolved in it, i.e. the so-called osmolality.
| Space | H2O (in liters) | H2O (% of body mass) | H2O (% of total water) |
| ICT | 28 | 40 | 65 |
| ECT | 14 | 20 | 35 |
| * IST | 11 | 15 | 25 |
| * plasma | 3 | 5 | 10 |
| in total | 42 | 60 | 100 |
- Children have the content of water in the body higher (70−80%), and the proportion of ICT and ECT is also different (newborn has the volume of ECT even higher than ICT).
- Failure in water metabolism are failures in osmoregulation. Normal plasma osmolality ranges from 275 to 295 mmol/kg. When it rises above the value of 278 mmol/kg, the secretion of antidiuretic hormone (ADH) begins. A further gradual increase in ADH secretion occurs as plasma osmolality increases – the maximum is reached at a value of 298 mmol/l. A further pathological increase in osmolality no longer leads to a further increase in ADH secretion. Another stimulus for ADH secretion is a 10-20% drop in circulating volume or a 5% drop in blood pressure. Anxiety, pain, some drugs (opiates, barbiturates, also chlorpropamide, acetaminophen) can have a similar effect.
Links[edit | edit source]
Related articles[edit | edit source]
- Dehydration
- Physical and chemical properties of water
- Water metabolism disorders
- Perspiratio insensibilis
Source[edit | edit source]
- With the permission of the autor adaptated from https://uloz.to/!CM6zAi6z/biofot-doc
- MASOPUST, Jaroslav – PRŮŠA, Richard. Patobiochemie metabolických drah. 2. edition. Charles University, 2004. 208 pp. pp. 170–171.
