Besides the chakras and tatvas, knowledge about Nadis is also essential before starting with Kundalini Science.
We have a network of subtle channels known as nadis inside our body through which the life force (prana) circulate. Ida, Pingala and Sushumna are considered the most important Nadis of our body even though in all there are fourteen Nadis.
The left channel is called the Ida Nadi. It is feminine, representing the moon and associated with river Ganga. Ida Nadi originates from Muldhara Chakra and ends up in the left nostril. This nadi is supposed to be cool.
Pingala Nadi is situated on right side. Its masculine, representing the Sun. Pingala Nadi is associated with River Yamuna. This nadi too originates from Muladhara and ends up at right nostril. Pingala nadi is considered hot.
Sushumna Nadi is the central channel. It runs along the spinal cord. This Nadi originates just below Muladhara chakra and runs up to Sahasrara chakra, which is positioned at the crown of the head. This Nadi is associated with river Saraswati. Sushumna Nadi in turn has three more channels/nadis, Vajra, Chitrini and Brahma nadi. Kundalini moves through this Sushumna Nadi when awakened.
The meeting place of these three Nadis in the Muldhara chakra is called as Yukta Triveni. Kundalini, symbolized by a serpent coiled into three and half circle, lies dormant at Muladhara chakra. It lies in such a manner that the serpent’s mouth blocks the entrance to Sushumna nadi. And only after Kundalini is awakened that Sushumna Nadi opens, else the channel/nadi remains closed.
Ida and Pingala rises from the Muldhara chakra and goes up while alternating from right to left sides at each chakra. At Ajna/Agya chakra both these Nadis meet Sushumna Nadi. The point at Ajna/Agya chakra where the three nadi meet is called Mukta Triveni. (See the Picture attached to see their position & movement)
From Mukta Triveni, Sushumna moves on to Sahasrara Chakra at the crown of head while Ida and Pingala Nadi moves towards left and right nostrils respectively.