Secretion of all of the following hormones is decreased on sectioning of pituitary stalk except:
**Core Concept**
The pituitary stalk connects the hypothalamus to the pituitary gland, enabling the transport of hypothalamic hormones that regulate the secretion of pituitary hormones. Sectioning the pituitary stalk disrupts this communication, affecting the secretion of various hormones.
**Why the Correct Answer is Right**
Since the question is incomplete, let's consider a general principle: sectioning the pituitary stalk typically decreases the secretion of hormones that are regulated by hypothalamic-releasing hormones, such as **thyroid-stimulating hormone (TSH)**, **follicle-stimulating hormone (FSH)**, **luteinizing hormone (LH)**, and **adrenocorticotropic hormone (ACTH)**. However, **prolactin** secretion is increased because the primary regulation of prolactin secretion is inhibitory, mediated by **dopamine** from the hypothalamus.
**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific hormone listed, we can't provide a detailed explanation.
**Option B:** Similarly, without specifics, we can't address why this option is incorrect.
**Option C:** The same issue applies here.
**Option D:** Again, lacking the specific hormone, a detailed explanation isn't possible.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that sectioning the pituitary stalk leads to an increase in **prolactin** levels due to the loss of inhibitory control by **dopamine** from the hypothalamus. This is a critical exception to the general decrease in hormone secretion following such a procedure.
**Correct Answer:** D. Prolactin