This part of the brainstem has the following relations:

• Medially, third ventricle.
• Laterally, internal capsule and caudate nucleus.
• Superiorly, lateral ventricle, corpus callosum, fornix.
• Rostrally, interventricular foramen and lamina terminalis.

Subdivisions of the diencephalon:

• Epithalamus (pineal gland, habenular nuclei, striae medullaris)
• Thalamus
• Hypothalamus
• Subthalamus