Thirst

Thirst (from Old High German thirst, originally " dry [ in the throat ]") reports the existence of need. It is followed by drinking the willingness to act of the (healthy) human or animal.

Occurrence

It occurs when fluid deficiency or excess salt. If the water content in the body by about 0.5 %, the brain signals thirst. At a loss of about 10 % liquid there is a feeling of dryness in the mouth and speech disorders.

Fluid requirements

The daily fluid requirement of an adult is under normal conditions is about 2 liters. A part of this is absorbed by the food. Recommended is currently often a daily fluid intake of 1.5 liters, but it can also vary depending on the individual conditions ( weather, physical exertion, etc.).

Prolonged lack of fluid can damage the kidneys. The gradual loss of water in vessels and tissues is called dehydration. Your Symptom: A freshly drawn fold of skin above the clavicle remains "stand".

Physiology

Missing the body fluid, this is registered by osmoreceptors in the supraoptic nucleus of the hypothalamus. This leads to the triggering of a sense of thirst. In addition, it comes to the production of antidiuretic hormone ( ADH or vasopressin ), which - distributed in the neurohypophysis - increases water reabsorption in the kidney and thus reduces the liquid excretion.

Also in the kidney sit osmoreceptors which induce via the renin -angiotensin -aldosterone system, causing the adrenal cortex secretes the hormone aldosterone increases. Also this increases water reabsorption by increased Na reabsorption.

Thirst

The term sensation of thirst is a pleonasm, which is to illustrate that a sense is meant the not necessarily the act of drinking follows. The lack of sense of thirst is called Adipsie. An increased feeling of thirst is called polydipsia.

Language

Due to the in Central Europe almost everywhere accessible water resources and associated each time, be able to quench the thirst, has among other things developed in the German language does not have its own term for the opposite of thirst, as in other languages ​​- especially in dry regions resident peoples - is the case. 1999 was invented to the art word moral. It is the lack of thirst, comparable with sick when hungry, designate.

Sayings

• Figurative thirst is also used as a term for a ( violent ) craving: a thirst for freedom, blood thirst.
• A drink over the eight: more than useful or acceptable of an alcoholic beverage.
• Thirst is worse than homesickness: a metaphor for the experience that vital necessity on Emotional stands (see Maslow's hierarchy of needs ). The German soldiers during the Africa campaign attributed.
• Quench the thirst