Thirst is a basic and intrinsic craving for drinking fluids. When the plamsa concentration of ions increases as a result of dehydration or blood loss, thirst is stimulated in order to replenish the water lost. Test your basic knowledge of thirst physiology by taking this simple quiz.
(1) Dehydration (low blood volume, hypovolemia) leads to the release of this molecule into the bloodstream by juxtaglomerular cells of the kidneys.
(2) Dehydration (low blood volume, hypovolemia) is sensed by baroreceptor cells (juxtaglomerular cells) in the kidneys. This activity leads to the release of a hormone/enzyme into the bloodstream, which ultimately leads to the production of __________ which, among other actions, acts on the brain to stimulates thirst intensity.
(3) In response to dehydration (low blood volume, hypovolemia), the following structures/organs stimulate secretion of the antidiuretic hormone (ADH) from the posterior pituitary:
(4) Within the hypothalamus, the cells that act as osmoreceptors are the same neurons that synthesize and release the antidiuretic hormone (ADH, also known as vasopressin).
(5) The body responds to dehydration (low blood volume, hypovolemia) and increases in plasma osmolality by (1) stimulating antidiuretic hormone (ADH) secretion, and (2) stimulating thirst. Hypothalamic osmoreceptors as well as peripheral stretch receptors contribute to the two functions noted above. Under normal physiological conditions, which of these two mechanisms plays the dominant role?