- The hormone oxytocin is synthesized by specialized neurons located in the hypothalamus, specifically within the paraventricular and supraoptic nuclei.
- After synthesis, oxytocin is transported down the axons of these neurons to the posterior pituitary gland (neurohypophysis), where it is stored and eventually released into the bloodstream.

- It is important to note that the posterior pituitary itself does not produce oxytocin; rather, it functions as a storage and release site for hormones made in the hypothalamus.
- In contrast, the anterior pituitary synthesizes and secretes its own hormones, such as growth hormone and ACTH, but not oxytocin.

Other options like the adrenal medulla and thyroid gland have distinct endocrine functions unrelated to oxytocin synthesis.

Key Points:
- Oxytocin is synthesized in the hypothalamus.
- It is released by the posterior pituitary.
- The posterior pituitary stores and secretes oxytocin but does not synthesize it.
- The anterior pituitary produces different hormones.

Reference: Guyton and Hall Textbook of Medical Physiology, 14th Edition, Chapter 67: Hypothalamus and Pituitary Gland, p. 818-821