Pars nervosa

The pars nervosa is a neuroendocrine structure that, along with the anterior lobe, intermediate lobe, and infundibular stalk, makes up the pituitary gland. This structure lies within the sella turcica, a saddle-shaped indentation in the sphenoid bone that lies posterior to the nasopharynx. The pars nervosa is responsible for the secretion of the neurohypophysial hormones oxytocin and arginine vasopressin into the systemic circulation. Because these hormones play important roles in the regulation of blood pressure and osmolarity as well as parturition and lactation, their regulated secretion is typically considered the primary physiologic function of the pars nervosa ¹⁾.

The smaller, anteromedial, “pars nervosa” compartment contains CN IX, the Jacobson nerve (or the tympanic nerve, a branch of CN IX), and receives the venous return from the inferior petrosal sinus.