Endocrine glands are those glands which pour their secretion directly into

Options

A. Ducts
B. Substrate
C. Blood
D. All the above.

Answer

**Step-by-Step Solution:**

1. **Definition of Endocrine Glands**: Endocrine glands are specialized glands in the body that do not have ducts. This means they do not release their secretions through tubes or ducts like exocrine glands do.

2. **Secretion Process**: Instead of using ducts, endocrine glands secrete hormones directly into the bloodstream. This is a key characteristic that distinguishes them from other types of glands.

3. **Function of Hormones**: Once these hormones are released into the blood, they travel throughout the body to reach their target organs. The hormones then bind to specific receptors on these target organs, influencing their function and regulating various physiological processes.

4. **Examples of Endocrine Glands**: Common examples of endocrine glands include the hypothalamus, pituitary gland, thyroid gland, adrenal glands, and pancreas. Each of these glands plays a crucial role in hormone production and regulation.

5. **Conclusion**: Therefore, the correct answer to the question is that endocrine glands are those glands which pour their secretion directly into the blood.

**Final Answer**: Endocrine glands are those glands which pour their secretion directly into the blood.

---