Which one of the following pairs includes the organs which are only the endocrine glands

Options

A. Parathyroid and adrenal
B. Pancreas and parathyroid
C. Thymus and testes
D. Adrenal and ovary

Explanation

To solve the question "Which one of the following pairs includes the organs which are only the endocrine glands?", we need to identify which pairs consist solely of organs that function exclusively as endocrine glands. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand Endocrine Glands
Endocrine glands are specialized organs that secrete hormones directly into the bloodstream. They do not have ducts and are responsible for regulating various physiological processes in the body.

**Hint:** Remember that endocrine glands release hormones directly into the blood, unlike exocrine glands which have ducts.

### Step 2: Analyze the Given Options
We need to evaluate each option provided in the question to determine if both organs listed are exclusively endocrine glands.

**Hint:** Look for organs that do not perform any other functions besides hormone secretion.

### Step 3: Evaluate Each Option
1. **Parathyroid Gland and Adrenal Gland**
- The parathyroid glands are responsible for regulating calcium levels in the blood by secreting parathormone. They do not perform any other function.
- The adrenal glands secrete various hormones (like cortisol and adrenaline) and are solely involved in hormone production.
- **Conclusion:** Both are purely endocrine glands.

2. **Pancreas**
- The pancreas has both endocrine (insulin and glucagon secretion) and exocrine functions (secreting digestive enzymes). Therefore, it does not qualify as an exclusive endocrine gland.
- **Conclusion:** This option is incorrect.

3. **Thymus and Testes**
- The thymus is primarily an endocrine gland (secreting thymosin) but also functions as a lymphoid organ.
- The testes are primarily reproductive organs that also secrete testosterone.
- **Conclusion:** Neither organ is exclusively an endocrine gland.

4. **Adrenal and Ovary**
- The adrenal gland is an endocrine gland, but the ovary also functions as a reproductive organ (producing eggs) along with secreting hormones like estrogen and progesterone.
- **Conclusion:** This option is incorrect.

### Step 4: Identify the Correct Pair
After evaluating all options, the only pair that consists solely of endocrine glands is the **Parathyroid Gland and Adrenal Gland**.

**Final Answer:** The correct option is the first one: Parathyroid Gland and Adrenal Gland.

### Summary of Steps:
1. Understand what constitutes an endocrine gland.
2. Analyze each option to check for exclusive endocrine functions.
3. Evaluate the functions of each organ in the pairs.
4. Identify the correct pair based on the analysis.