Which structure lies between the two thalami in the fetal brain?

Which structure lies between the two thalami in the fetal brain?

• A. Third ventricle
• B. Lateral ventricle
• C. Corpus callosum
• D. Pineal gland

Answer: (A)

The space between the two thalami is the third ventricle. It is a narrow, midline cavity within the diencephalon that forms part of the ventricular system, with the thalami forming its lateral borders. The lateral ventricles are located within each cerebral hemisphere and connect to the third ventricle via the foramina of Monro, so they are not situated between the thalami. The corpus callosum runs above the ventricles, linking the two hemispheres, but it does not lie in the space between the thalami. The pineal gland sits posterior to the third ventricle, in the posterior midline region, and likewise is not between the thalami.

The space between the two thalami is the third ventricle. It is a narrow, midline cavity within the diencephalon that forms part of the ventricular system, with the thalami forming its lateral borders. The lateral ventricles are located within each cerebral hemisphere and connect to the third ventricle via the foramina of Monro, so they are not situated between the thalami. The corpus callosum runs above the ventricles, linking the two hemispheres, but it does not lie in the space between the thalami. The pineal gland sits posterior to the third ventricle, in the posterior midline region, and likewise is not between the thalami.