Posterior Pituitary
The rear lobe of the pituitary gland (neurohypophysis) that stores and releases oxytocin and vasopressin. These hormones are actually produced in the hypothalamus and transported to the posterior pituitary for storage. Both are available as approved therapeutic peptide drugs.
Technical Context
The posterior pituitary (neurohypophysis) develops embryologically from neural tissue and is functionally an extension of the hypothalamus. Magnocellular neurons in the supraoptic and paraventricular nuclei of the hypothalamus synthesise oxytocin and vasopressin, which are transported along axons to the posterior pituitary for storage in nerve terminals. Release is triggered by neuronal action potentials. Oxytocin release is stimulated by cervical dilation during labour and infant suckling (positive feedback — the Ferguson reflex). Vasopressin release is stimulated by increased plasma osmolality (detected by osmoreceptors) and decreased blood volume (detected by baroreceptors). Both hormones are available as approved therapeutic peptides.