Step-by-step explanation:
fluid intake is governed by thirst and it is regulated by a group of hypothalamic neurons called , which respond to angiotensin ii and to rising osmolarity of the ecf.
The group of hypothalamic neurons that regulate fluid intake in response to various stimuli are known as osmoreceptors. These specialized cells are located in the hypothalamus region of the brain, specifically in an area called the supraoptic nucleus and the paraventricular nucleus.
Osmoreceptors play a critical role in maintaining fluid balance in the body. They are sensitive to changes in the concentration of electrolytes and solutes in the extracellular fluid (ECF). When the concentration of solutes in the ECF increases, the osmoreceptors detect this change and trigger the sensation of thirst. This encourages the individual to drink fluids, which helps to restore the fluid balance in the body.
In addition to osmoreceptors, the renin-angiotensin-aldosterone system (RAAS) also plays a role in regulating fluid balance in the body. When the body experiences a decrease in blood pressure or blood volume, the kidneys release the hormone renin. Renin acts on a protein called angiotensinogen, which is produced in the liver, to produce angiotensin I. Angiotensin I is then converted to angiotensin II, which acts on the osmoreceptors in the hypothalamus to stimulate thirst and increase fluid intake. Angiotensin II also acts on the kidneys to increase the reabsorption of sodium and water, which helps to restore blood volume and pressure.
Overall, the regulation of fluid intake is a complex process that involves the interaction of multiple systems in the body, including the osmoreceptors and the RAAS. These systems work together to maintain fluid balance in the body, which is critical for maintaining normal physiological function.