Which of the following statements or structures is not correct about the midbrain?

Options

A. Located between the thalamus/hypothalamus and pons
B. Has arbor vitae
C. Has a canal (Cerebral aqueduct)
D. Its dorsal part consists of 4 lobes (corpora quadrigeminal)

Answer

To determine which statement or structure is not correct about the midbrain, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Identify the Location of the Midbrain**:
- The midbrain is located between the thalamus (above) and the pons (below). This is a correct statement about the midbrain.

2. **Check for the Presence of the Cerebral Aqueduct**:
- The midbrain contains the cerebral aqueduct, which is a canal that connects the third ventricle to the fourth ventricle. This statement is also correct.

3. **Examine the Function of the Corpora Quadrigemina**:
- The corpora quadrigemina, located in the midbrain, serves as reflex centers for vision and hearing. This is another correct statement regarding the midbrain.

4. **Identify the Incorrect Statement**:
- Since the first, second, and third statements are correct, we need to identify which one is not correct. Based on the analysis, the second option is the one that is incorrect regarding the midbrain.

### Conclusion:
The correct answer is **option second**, as it contains an incorrect statement about the midbrain.