Transitional epithelium occurs in

Options

A. Blood vessels
B. Trachea
C. Kidney
D. Ureter/Urinary bladder.

Answer

**Step-by-Step Solution:**

1. **Understanding Transitional Epithelium:**
- Transitional epithelium is a specialized type of epithelium that can change its shape and size. It is designed to stretch and contract, which is essential for organs that need to accommodate varying volumes of fluid.

2. **Evaluating the Options:**
- **Option 1: Blood Vessels**
- Blood vessels are lined with simple squamous epithelium, which is not transitional. Therefore, this option is incorrect.

- **Option 2: Trachea**
- The trachea is lined with pseudostratified columnar epithelium, which also does not change shape like transitional epithelium. Hence, this option is incorrect.

- **Option 3: Kidney**
- The kidney contains simple cuboidal epithelium, which is involved in absorption and secretion but does not exhibit the characteristics of transitional epithelium. Thus, this option is incorrect.

- **Option 4: Ureter and Urinary Bladder**
- The ureter and urinary bladder are organs that store and transport urine. The urinary bladder, in particular, needs to expand and contract as it fills and empties. This organ is lined with transitional epithelium, which allows it to stretch when filled with urine. Therefore, this option is correct.

3. **Conclusion:**
- Based on the evaluation of all options, the correct answer is that transitional epithelium occurs in the **ureter and urinary bladder**.

**Final Answer: Transitional epithelium occurs in the ureter and urinary bladder.**

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