Posterior pituitary neurosecretory cells extending from the supraoptic and paraventricular nuclei of the hypothalamus. These axons store and release neurohypophysial hormones oxytocin and vasopressin into the neurohypophyseal capillaries, from there they get into the systemic circulation (and partly back into the hypophyseal portal system). In addition to axons, the posterior pituitary also contains pituicytes, specialized glial cells resembling astrocytes assisting in the storage and release of the hormones. Classification of the posterior pituitary varies, but most sources include the two regions below: The median eminence is only occasionally included as part of the posterior pituitary. Other sources specifically exclude it from the
Pituitary stalk interruption syndrome Pituitary stalk interruption syndrome Pituitary stalk interruption syndrome (PSIS) is a congenital disorder characterised by the triad of an absent or exceedingly thin pituitary stalk, an ectopic or absent posterior pituitary and/or absent or hypoplastic anterior pituitary. Affected individuals may present with hypoglycaemia during the neonatal period, or with growth retardation during childhood (those diagnosed in the neonatal period appear to be affected by a particularly severe form of the disorder). PSIS is a common cause of congenital hypopituitarism, and causes a permanent growth hormone deficit. Some PSIS-affected individuals may also present with adrenal hypoplasia (5-29%), diabetes insipidus (5-29%), primary