Questions: How are the posterior pituitary and anterior pituitary similar? Both are connected to the hypothalamus via a portal system. Both produce hormones that control other glands. Both produce releasing and inhibiting hormones. Both produce three or more hormones. Both are controlled by the hypothalamus.

The answer is the last one: Both are controlled by the hypothalamus.

Explanation for each option:

1. Both are connected to the hypothalamus via a portal system.

   • Incorrect. Only the anterior pituitary is connected to the hypothalamus via the hypophyseal portal system, which allows hypothalamic hormones to directly reach the anterior pituitary. The posterior pituitary is connected to the hypothalamus through nerve fibers.

2. Both produce hormones that control other glands.

   • Incorrect. The anterior pituitary produces hormones that control other glands (e.g., ACTH, TSH), but the posterior pituitary does not produce hormones; it stores and releases hormones (e.g., oxytocin and vasopressin) produced by the hypothalamus.

3. Both produce releasing and inhibiting hormones.

   • Incorrect. The anterior pituitary does not produce releasing and inhibiting hormones; these are produced by the hypothalamus to regulate the anterior pituitary. The posterior pituitary does not produce these hormones either.

4. Both produce three or more hormones.

   • Incorrect. The anterior pituitary produces several hormones, but the posterior pituitary does not produce hormones; it only stores and releases two hormones.

5. Both are controlled by the hypothalamus.

   • Correct. Both the anterior and posterior pituitary are regulated by the hypothalamus, though through different mechanisms. The anterior pituitary is regulated by hypothalamic hormones, while the posterior pituitary is controlled by neural signals from the hypothalamus.

In summary, the similarity between the posterior and anterior pituitary is that both are controlled by the hypothalamus.