Hormone that does not pass through hypophyseal portal veins is

Options

A. GnRH
B. TRH
C. Oxytocin
D. GHRH

Answer

To determine which hormone does not pass through the hypophyseal portal veins, we need to understand the function of these veins and the hormones involved.

### Step-by-Step Solution:

1. **Understanding Hypophyseal Portal Veins**:
- The hypophyseal portal veins are a network of blood vessels that connect the hypothalamus to the anterior pituitary gland. They facilitate the transport of hormones from the hypothalamus to the anterior pituitary.

2. **Identifying Hormones Involved**:
- Hormones that typically pass through the hypophyseal portal veins include:
- GnRH (Gonadotropin-Releasing Hormone)
- TRH (Thyrotropin-Releasing Hormone)
- GHRH (Growth Hormone-Releasing Hormone)

3. **Analyzing Oxytocin**:
- Oxytocin is produced in the hypothalamus but is released into the bloodstream via the posterior pituitary gland, not through the hypophyseal portal veins.

4. **Conclusion**:
- Among the hormones listed, oxytocin is the one that does not pass through the hypophyseal portal veins. Therefore, the answer to the question is **oxytocin**.