Which one options is correct ?

Options

A. Posterior pituitary is connected to hypothalamus by nerve fibres
B. Anterior pituitary is connected to hypothalamus by portal vessel
C. Posterior pituitary is connected to hypothalamus by portal vessel
D. Both a and b

Answer

To solve the question regarding the connection between the pituitary gland and the hypothalamus, we will analyze the statements provided and determine which one is correct.

### Step-by-Step Solution:

1. **Understanding the Pituitary Gland Structure**:
- The pituitary gland consists of two parts: the anterior pituitary and the posterior pituitary.
- The anterior pituitary is responsible for producing and releasing various hormones, while the posterior pituitary stores and releases hormones produced by the hypothalamus.

2. **Connection of the Posterior Pituitary**:
- The posterior pituitary is connected to the hypothalamus via nerve fibers. This is correct as the hormones released from the posterior pituitary (like oxytocin and ADH) are synthesized in the hypothalamus and transported down the nerve fibers.

3. **Connection of the Anterior Pituitary**:
- The anterior pituitary is connected to the hypothalamus through a network of blood vessels known as the hypophyseal portal system. This allows the hypothalamus to regulate the anterior pituitary's hormone secretion by releasing regulatory hormones into the portal circulation.

4. **Identifying the Correct Statement**:
- Based on the information, we can conclude that:
- The posterior pituitary is connected to the hypothalamus by nerve fibers (correct).
- The anterior pituitary is connected to the hypothalamus by portal vessels (correct).
- Therefore, both statements about the connections of the anterior and posterior pituitary to the hypothalamus are correct.

5. **Final Conclusion**:
- Since both connections are accurately described, the correct option would be the one that states both the posterior pituitary is connected by nerve fibers and the anterior pituitary is connected by portal vessels.