Search results
Results From The WOW.Com Content Network
Many of its neurons project to the posterior pituitary where they secrete oxytocin, and a smaller amount of vasopressin. Other secretions are corticotropin-releasing hormone (CRH) and thyrotropin-releasing hormone (TRH). [1] CRH and TRH are secreted into the hypophyseal portal system, and target different neurons in the anterior pituitary.
An increase in vasopressin has been observed in female rats which have just given birth. Vasopressin is associated with aggressive and hostile behaviours, and is postulated to decrease sexual motivation in females. Vasopressin administered in the female rat brain has been observed to result in an immediate decrease in sexual motivation. [13]
Vasopressin regulates the tonicity of body fluids. It is released from the posterior pituitary in response to hypertonicity and causes the kidneys to reabsorb solute-free water and return it to the circulation from the tubules of the nephron, thus returning the tonicity of the body fluids toward normal.
An antidiuretic is a substance that helps to control fluid balance in an animal's body by reducing urination, [1] opposing diuresis. [2] Its effects are opposite that of a diuretic. The major endogenous antidiuretics are antidiuretic hormone (ADH; also called vasopressin) and oxytocin.
The oxytocin and vasopressin that is released at the posterior pituitary gland enters the blood, and cannot re-enter the brain because the blood–brain barrier does not allow oxytocin and vasopressin through, but the oxytocin and vasopressin that is released from dendrites acts within the brain. Oxytocin neurons themselves express oxytocin ...
Vasopressin is produced from the vasopressin-producing cells via the AVP gene, a molecular output of circadian pathways. [citation needed] Magnocellular neurosecretory cells in rats (where these neurons have been most extensively studied) in general have a single long varicose axon, which projects to the posterior pituitary.
Also called the neural lobe or posterior lobe, this region constitutes the majority of the posterior pituitary and is the storage site of oxytocin and vasopressin. Sometimes (incorrectly) considered synonymous with the posterior pituitary, the pars nervosa includes Herring bodies and pituicytes .
In 1950, Geoffrey Harris and Barry Cross outlined the oxytocin pathway by studying oxytocin release in response to electrical stimulation. [24] In 1974, Walters and Hatton investigated the effect of water dehydration by electrically stimulating the supraoptic nucleus—the hypothalamic center responsible for the release of vasopressin. [ 24 ]