What Are the Functions of Supraoptic & Paraventricular Nucleus?

The supraoptic and paraventricular nulcei and groups of cells in the brain that are responsible for regulating blood pressure and fluid balance via the secretion of certain hormones. Both of these nuclei are located in the hypothalamus of the brain, a structure that regulates the balance of biochemical reactions in your body. The activity of these nuclei are regulated by blood pressure and concentrations of certain chemicals in your blood.

Fluid Balance

• Nearly half of your body's energy expenditure at rest goes to maintaining the balance of fluid balance in your body. The proper balance of water, minerals, nutrients and vitamins is critical for the biochemical reactions that sustain life. Your body will adjust many factors to maintain this balance: Blood pressure, mineral retention in the kidneys, mineral and water retention in body tissues and behavior such as thirst or salt craving.

Supraoptic Nucleus

• The supraoptic nucleus is a group of approximately 3,000 cells in the hypothalamus responsible for producing anti-diuretic hormone, or vasopressin. Vasopressin stimulates the body to raise blood pressure and retain water. Neurons of the supraoptic nucleus stimulate other cells in the posterior pituitary gland to effect hormone release.

Paraventricular Nucleus

• The paraventricular nucleus is another nucleus of the hypothalamus responsible for secreting hormones into circulation. These hormones include vasopressin as well as oxytocin, both known to be involved in pair-bonding behavior. Paraventricular neurons also secrete corticotropin-releasing hormone, CRN, that regulates hormone release from the pituitary as well as thyrotropin-releasing hormone, TRH, that stimulates the release of thyroid stimulating hormone and prolactin. Where the surpaoptic nucleus's role is focus on controlling blood pressure, the function of the paraventricular nucleus extends to many of the body's regulatory systems.

Regulation

• Neurons in the supraoptic and paraventricular nucleus receive input from wide and varied regions of the brain. In addition to responding directly to changes in blood pressure or mineral concentration, more complex states of the brain, such as stress, strong emotions, sexual stimulation or anxiety, can alter levels of hormone release.