Which hormone along these is not secreted by an endocrine gland?

Options

A. ADH
B. ANF
C. T4
D. PTH

Answer

To determine which hormone is not secreted by an endocrine gland, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the Hormones**: The hormones mentioned are ADH (Antidiuretic Hormone), ANF (Atrial Natriuretic Factor), T4 (Thyroxine), and PTH (Parathyroid Hormone).

2. **Examine ADH**:
- ADH is synthesized in the hypothalamus and released from the posterior pituitary gland.
- The posterior pituitary is considered an endocrine gland because it releases hormones into the bloodstream.

3. **Examine ANF**:
- ANF is secreted by the atria of the heart.
- The heart is primarily a muscular organ and not classified as an endocrine gland, even though it produces hormones.

4. **Examine T4**:
- T4 (Thyroxine) is produced by the thyroid gland.
- The thyroid gland is an endocrine gland that plays a crucial role in metabolism.

5. **Examine PTH**:
- PTH (Parathyroid Hormone) is secreted by the parathyroid glands.
- The parathyroid glands are also classified as endocrine glands and are involved in regulating calcium levels in the blood.

6. **Conclusion**:
- Among the hormones listed, ANF is the only one that is not secreted by an endocrine gland, as it is produced by the heart.

### Final Answer:
The hormone that is not secreted by an endocrine gland is **ANF (Atrial Natriuretic Factor)**.

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