Transection of pituitary stalk leads to increase in

Options

A. TSH
B. Prolactin
C. GH
D. ACTH

Answer

**Step-by-Step Solution:**

1. **Understanding the Pituitary Gland**: The pituitary gland is a small gland located at the base of the brain, often referred to as the "master gland" because it regulates various hormonal functions in the body. It consists of three lobes: the anterior lobe, the posterior lobe, and the intermediate lobe.

2. **Role of the Hypothalamus**: The hypothalamus is a region of the brain that controls the pituitary gland. It sends signals to the pituitary through the pituitary stalk, which is also known as the hypophyseal stalk.

3. **Function of the Pituitary Stalk**: The pituitary stalk is responsible for transmitting hormones from the hypothalamus to the pituitary gland. This includes both releasing hormones (which stimulate hormone production) and inhibitory hormones (which prevent hormone production).

4. **Impact of Transection of Pituitary Stalk**: When the pituitary stalk is transected (cut), the communication between the hypothalamus and the pituitary gland is disrupted. This means that the inhibitory signals from the hypothalamus can no longer reach the pituitary gland.

5. **Dopamine's Role**: One of the key hormones transmitted via the pituitary stalk is dopamine, which acts as an inhibitory hormone on prolactin-producing cells in the anterior lobe of the pituitary gland. Dopamine inhibits the secretion of prolactin.

6. **Consequences of Dopamine Inhibition**: With the transection of the pituitary stalk, dopamine is no longer able to inhibit prolactin secretion. As a result, the prolactin-producing cells become more active and start producing prolactin in larger amounts.

7. **Conclusion**: Therefore, the transection of the pituitary stalk leads to an increase in the secretion of prolactin due to the loss of inhibitory control from dopamine.

**Final Answer**: Transection of the pituitary stalk leads to an increase in prolactin levels.

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