Suṣumṇā

Central channel (Meru-daṇḍa)

Central nāḍī running from the kanda (perineal region) to brahma-randhra at the crown. Sat-Chakra-Nirūpaṇa describes its inner structure as three nested tubes (suṣumṇā / vajra / citrinī); kuṇḍalinī rises through citrinī. The point shown here is the channel's mid-axis representative; the diagram overlay renders the full path.