The Effect of Caffeine on Water Re-absorption in Kidney - Lab Report Example

"ADH acts on the kidneys, concentrating the urine by promoting the re-absorption of water from the cortical collecting duct. Peptide hormones are a class of peptides that are secreted into the blood stream and have endocrine functions in living animals. ." (Anti diuretic hormone, 8 October 2008). The activation process of ADH is done by water receptors and these water receptors are located in extracellular fluid as well as intracellular fluid. It is very important to maintain water homeostasis and this is done by controlling two things namely, the osomolality and the intravascular blood volume.

In the body of a human being water is lost by various activities such as breathing, which contributes the maximum in loss of water in a human body other activities include sweating, urination etc. "While several of these processes occur autonomic in healthy individuals, body water homeostasis is tightly controlled by regulating both water intake (drinking) and urinary water excretion. Changes in intravascular blood volume are sensed by vascular volume- and baroreceptors, which regulate the release of the anti diuretic hormone arginine vasopressin (AVP).

" (Physiology, 8 October 2008) Caffeine is a diuretic; a diuretic is a drug which elevat. Re-absorption of water increases blood volume and concentrates the urine." (ADH, 8 October 2008). As discussed earlier in the paper that hypothalamus maintains a balance in the body and this is exactly where hypothalamus comes into effect, when hypothalamus detects a decrease in water level in blood, ADH is secreted, and the same is secreted by the posterior pituitary. ADH mainly targets the kidneys because the ultimate role of kidneys is to make sure that there is a good balance of the fluids in the body.

The main function of ADH is to concentrate the urine and make sure that there is less of amount of water loss which is taking place in the body, it reduces the urine volume and prevents water loss from the body. Caffeine is responsible for reducing the vasopressin secretion, "Vasopressin is secreted from the posterior pituitary gland in response to reductions in plasma volume and in response to increases in the plasma osomolality" (Vasopressin, 8 October 2008). When caffeine is in took, it results in the reduction of vasopressin secretion, which ultimately means that the water re absorption gets reduced in the body and the output of urine becomes very frequent.

The same can be understood with the help of an example, if we consume more coffee which has high levels of caffeine in it, we tend to become restless and the anxiety level in our body tends to rise to an alarmingly high level, all this happens because of the presence of caffeine in coffee, the ultimate result of consuming more coffee will be dehydration because of the levels of caffeine present in the same. Caffeine causes the body to lose excessive amount of water and if coffee is consumed excessively, dehydration becomes inevitable.

It is very easy to