Which of the following is wrong

Options

A. Sella turcica is a bony cavity where pituitary gland is located
B. Parathyroid hormone decreases the `Ca^(2+)` levels in blood
C. Thymosins play a major role in T-cell differentiation
D. The middle layer of adrenal cortex is zona fasciculata

Answer

To determine which statement is incorrect, we will analyze each of the four statements provided in the question.

### Step-by-Step Solution:

1. **Analyze the First Statement**:
- **Statement**: "Sella turcica is a bony cavity where pituitary gland is located."
- **Explanation**: This statement is correct. The pituitary gland is indeed located in a bony cavity called the sella turcica, which is part of the sphenoid bone in the skull. It is also connected to the hypothalamus by a stalk (infundibulum).

2. **Analyze the Second Statement**:
- **Statement**: "Parathyroid hormone decreases the calcium levels in blood."
- **Explanation**: This statement is incorrect. The parathyroid hormone (PTH) is secreted by the parathyroid glands and functions to increase calcium levels in the blood, not decrease them. Therefore, this statement is the wrong one.

3. **Analyze the Third Statement**:
- **Statement**: "Thymosins play a major role in T cell differentiation."
- **Explanation**: This statement is correct. Thymosins are hormones produced by the thymus gland and are crucial for the differentiation and maturation of T lymphocytes, which are essential for the immune response.

4. **Analyze the Fourth Statement**:
- **Statement**: "The middle layer of adrenal cortex is zona fasciculata."
- **Explanation**: This statement is correct. The adrenal cortex has three layers: zona glomerulosa (outer), zona fasciculata (middle), and zona reticularis (inner). The zona fasciculata is responsible for producing glucocorticoids.

### Conclusion:
After evaluating all statements, the incorrect statement is the second one: "Parathyroid hormone decreases the calcium levels in blood."

### Final Answer:
The wrong statement is: **B. Parathyroid hormone decreases the calcium levels in blood.**

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