Diencephalon represents
The diencephalon is the pa of brain between the cerebrum and brainstem.The cavity within it is called third ventricleThe pas of diencephalon are:ThalamusMetathalamusEpithalamusSubthalamusHypothalamus(Ref: Vishram Singh textbook of clinical neuroanatomy Second Edition pg -123)
Lateral ventricle
3rd ventricle
4th ventricle
Aquedct
Brain 