“Question to T Krishnamacharya –
Q: Some people describe that Kuṇḍalinī
goes through the Suṣumṇā
to the Sahasrāra.
Is this correct?
A: No, it is the Prāṇa Vāyu that
moves through the Suṣumṇā.
– Śrī Krishnamacharya – The Pūrnācārya
– published by the KYM in 1997″

“There are two different energies which are in conflict – Ha and Ṭha.
Because of these two energies we are not in our natural state.
Why do they never meet?
Because there is a big obstacle in the form of a coiled serpent.
Further we add to the obstacle rather than reduce it.
Through practices we can use the fire that is in our system to slowly reduce the obstacle.
When this happens the two have the possibility of entering Suṣumnā and become one.
When this happens there is the union of Ha and Ṭha.”
– TKV Desikachar

“The great yogin Yājñavalkhya said that the constant and intensive
practice of Prāṇāyāma brought Prāṇa and Agni together,
and gradually the obstacle at the base of the Suṣumṇā would be totally dissolved.
He gave this block the name ‘Kuṇḍali’ meaning coiled
or ‘Kuṇḍalinī’ meaning ‘rolled up’ in other texts.
Kuṇḍalinī represents that which blocks access to the central energetic channel.
When this obstacle is eliminated, Prāṇa penetrates
and begins to rise in the central channel.
This is the most precise description we have of the process.
This is also the most clear and coherent.”
– ‘Concerning the Cakra’ by TKV Desikachar

“The obstacle is also called Kuṇḍalinī because it looks like an earring
worn by women in the olden days and Kuṇḍali means ‘earring’.
It is also called Śakti because its power is so great that
it is able to block the flow of Prāṇa into the Suṣumṇā.
We must note that it is Prāṇa that is eventually
supposed to go into the Suṣumṇā.
Many books describe that which goes up as Kuṇḍalinī.
Kuṇḍalinī does not go up.
Suṣumṇā is like a conductor through which energy flows.
This energy is the same energy that is always present, Prāṇa.”
– TKV Desikachar Religiousness in Yoga
‘Various Approaches to Yoga’
Chapter Seventeen Page 243-244

“The terms Ha and Ṭha also represent
two extreme sides of a wavering mind.
Ha often is meant to represent the sun, Ṭha the moon.
Suṣumṇā in the middle Nāḍī.
Prāṇa in the Ha and Ṭha represents
a confused and wavering mind.
Prāṇa in the  Suṣumṇā represents a clear, steady mind.
Hence, Jñāni is one whose Prāṇa is in Suṣumṇā
and Ajñāni is one whose Prāṇa is still
in the opposite two Nāḍī, Ha and Ṭha.”
– TKV Desikachar Religiousness in Yoga
‘Various Approaches to Yoga’
Chapter Seventeen Page 246-247

Links to Related Posts:

The presence and actions of Prāṇa Śakti……..

Prāṇa – Its origin, function and malfunction

Religiousness in Yoga Study Guide: Chapter Seventeen Theory: Various Approaches to Yoga Pages 237-249