Which of these glands directly releases its secretions into the blood stream?

Options

A. Mammary glands
B. Pituitary gland
C. Sweat glands
D. Sebaceous glands

Answer

To solve the question "Which of these glands directly releases its secretions into the bloodstream?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Identify the Glands**: We need to look at the options provided and identify the glands mentioned. The options are:
- Mabry's glands
- Pituitary gland
- Sweat glands
- Sebaceous glands

2. **Analyze Mabry's Glands**:
- Mabry's glands are known for secreting milk. They do not release their secretions directly into the bloodstream; instead, they release milk through ducts.

3. **Analyze the Pituitary Gland**:
- The pituitary gland is an endocrine gland. Endocrine glands are characterized by releasing their hormones directly into the bloodstream. Therefore, the pituitary gland does release its secretions directly into the bloodstream.

4. **Analyze Sweat Glands**:
- Sweat glands are classified as exocrine glands. They secrete sweat through ducts onto the surface of the skin, not directly into the bloodstream.

5. **Analyze Sebaceous Glands**:
- Sebaceous glands also fall under the category of exocrine glands. They secrete sebum (an oily substance) through ducts onto the skin's surface, not into the bloodstream.

6. **Conclusion**:
- After analyzing all the options, we find that the only gland that directly releases its secretions into the bloodstream is the **Pituitary gland**.

### Final Answer:
The correct answer is the **Pituitary gland**.

---