How many of the following hormones are synthesised by the hypothalamus ?
(I) growth hormone releasing hormone
(II) prolactin inhibitory hormone
(III) Thyroid stimulating hormone
(IV) aldosterone
(V) luteinizing hormone
(VI) follicle stimulating hormone

Options

A. Tow
B. Three
C. Six
D. One

Answer

To determine how many of the listed hormones are synthesized by the hypothalamus, we will analyze each hormone one by one:

1. **Growth Hormone Releasing Hormone (GHRH)**: This hormone is indeed synthesized by the hypothalamus. It stimulates the anterior pituitary to release growth hormone.

2. **Prolactin Inhibitory Hormone (PIH)**: This hormone, also known as dopamine, is produced by the hypothalamus. It inhibits the secretion of prolactin from the anterior pituitary.

3. **Thyroid Stimulating Hormone (TSH)**: This hormone is not synthesized by the hypothalamus. It is produced by the anterior pituitary gland and stimulates the thyroid gland to produce thyroid hormones.

4. **Aldosterone**: This hormone is produced by the adrenal glands, not the hypothalamus. It plays a role in regulating sodium and potassium levels in the body.

5. **Luteinizing Hormone (LH)**: This hormone is synthesized by the anterior pituitary gland, not the hypothalamus. It is involved in regulating the menstrual cycle and ovulation in females and testosterone production in males.

6. **Follicle Stimulating Hormone (FSH)**: Similar to LH, FSH is also produced by the anterior pituitary gland and is not synthesized by the hypothalamus. It is important for reproductive processes.

Now, summarizing the hormones synthesized by the hypothalamus:
- GHRH (1)
- PIH (2)

Thus, the total number of hormones synthesized by the hypothalamus from the given list is **2**.

### Final Answer:
**2 hormones are synthesized by the hypothalamus.**