Histologically the two parts of the pituitary gland reflect their origins, as seen in this low-magnification section of an entire gland . the infundibular stalk (IS) and pars nervosa (PN) of the neurohypophysis resemble CNS tissue, while the adenohypophysis’ pars distalis (PD). Pars intermediate(PI) and pars tuberalis (PT) are typically glandular in their level of staining.