Endocrine glands are those glands which pour their secretion directly into

Options

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

Explanation

**Step-by-Step Solution:**

1. **Understanding Endocrine Glands**: Begin by defining what endocrine glands are. Endocrine glands are specialized glands in the body that do not have ducts. They are responsible for producing hormones.

2. **Identifying the Function of Endocrine Glands**: Recognize that the primary function of endocrine glands is to release hormones directly into the bloodstream. This is different from exocrine glands, which release their secretions through ducts.

3. **Analyzing the Options**: Look at the given options:
- Option 1: Ducts
- Option 2: Substrate
- Option 3: Blood
- Option 4: All of the above

4. **Evaluating Each Option**:
- Option 1 (Ducts): This is incorrect because endocrine glands are ductless.
- Option 2 (Substrate): This is also incorrect as there is no secretion into a substrate.
- Option 3 (Blood): This is correct, as endocrine glands secrete hormones directly into the blood.
- Option 4 (All of the above): This is incorrect since not all options are correct.

5. **Conclusion**: Based on the analysis, the correct answer is Option 3: Blood. Endocrine glands pour their secretion (hormones) directly into the bloodstream.

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

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