Posterior pituitary stores and releases hormones produced by the hypothalamus; it is controlled by neuronal signals from the hypothalamus.

• A. True
• B. False
• C. It stores and releases hormones produced by the thyroid
• D. It is not connected to the hypothalamus

Answer: (A)

The key idea is how the posterior pituitary relies on the hypothalamus for hormone production and release. The posterior pituitary doesn’t make hormones itself; it stores oxytocin and vasopressin that are produced by hypothalamic neurons. These hormones travel down the neuron’s axons to the posterior pituitary, where nerve impulses trigger their release into the bloodstream. So, the posterior pituitary is controlled by neuronal signals from the hypothalamus and acts as a storage-and-release site for hypothalamic hormones. It’s also worth noting that this pathway is neural, not through the portal system used by the anterior pituitary. The notion that the posterior pituitary stores thyroid hormones is incorrect, since thyroid hormones come from the thyroid gland.