An increase in volume causes inhibition of the thirst centre and inhibits ADH release causing more water to be excreted. Stretch receptors in the upper GI tract also detect changes in water levels. The passage of a bolus of fluid down the upper GI tract inhibits the release of ADH before absorption of the fluid has taken place. In relation to our results, Table 1 shows the statistical data in regards to the flow rate. To sum up, the effects of water loading on the body cause water to excreted reasonably quickly after intake, starting within 30 minutes with optimum flow at 60minutes.
Loading also causes the desire to drink to be inhibited.
This excess water is detected by a number of systems, whose purpose is to maintain a steady internal environment. By losing a certain volume of excess water, this will allow, for example, the blood pressure to decrease and the atrial stretch receptors to detect this. Constant negative feedback will initiate a signal when required and ADH levels will return to normal or an appropriate level. In terms of saline loading, this causes a decrease in water excretion in a bid to bring the salt concentration in the body back to normal. This is to allow for the cells concentration to remain constant, and prevent shrinking, by fluid moving out of the cells in a bid to reach an internal equilibrium.