Gland
Neurohypophysis (posterior pituitary)
Hypothalamic axons releasing vasopressin and oxytocin
High-yield
Both supraoptic and paraventricular nuclei contain neurons making these hormones. Assigning vasopressin exclusively to one nucleus and oxytocin exclusively to the other is inaccurate.
Overview
The posterior pituitary is a neural continuation of the hypothalamus. Its pars nervosa contains axons, supporting pituicytes and a vascular network. Vasopressin and oxytocin are synthesized in hypothalamic neurons, transported along their axons, and released into blood from the posterior lobe.
Reference facts
- Location
- The pars nervosa occupies the posterior pituitary and remains continuous with the infundibulum.
- Hormones
- Stores and releases hypothalamic vasopressin and oxytocin. Secretory material accumulates in axonal swellings and terminals, including Herring bodies.
- Blood supply
- Predominantly inferior hypophyseal arteries, with connections from the superior hypophyseal system.
- Innervation
- Axons from hypothalamic magnocellular neurosecretory neurons terminate near its capillaries.
- Function
- Vasopressin increases renal collecting-duct water reabsorption; oxytocin supports uterine contraction and milk ejection.
Clinical correlation
Disruption of this system can cause arginine vasopressin deficiency, formerly called central diabetes insipidus, with excessive dilute urine. After injury or surgery, water-balance disturbances may change over time; their duration is not determined by a simple high-versus-low lesion rule.
Frequently asked questions
Where is the neurohypophysis (posterior pituitary) located?
The pars nervosa occupies the posterior pituitary and remains continuous with the infundibulum.
What does the neurohypophysis (posterior pituitary) secrete?
Stores and releases hypothalamic vasopressin and oxytocin. Secretory material accumulates in axonal swellings and terminals, including Herring bodies.
What does the neurohypophysis (posterior pituitary) do?
Vasopressin increases renal collecting-duct water reabsorption; oxytocin supports uterine contraction and milk ejection.
What is the blood supply of the neurohypophysis (posterior pituitary)?
Predominantly inferior hypophyseal arteries, with connections from the superior hypophyseal system.