This is between the two parietal and occipital bones. This portion is very soft in a babe. When the child grows, it gets obliterated by the growth of the bones of the head. Brahma created the physical body and entered (Pravishat) the body to give illumination inside through this Brahmarandhra. In some of the Upanishads, it is stated like that. This is the most important part. It is very suitable for Nirguna Dhyana (abstract meditation). When the Yogi separates himself from the physical body at the time of death, this Brahmarandhra bursts open and Prana comes out through this opening (Kapala Moksha). “A hundred and one are the nerves of the heart. Of them one (Sushumna) has gone out piercing the head; going up through it, one attains immortality” (Kathopanishad).
Sahasrara Chakra:
Sahasrara Chakra is the abode of Lord Siva. This corresponds to Satya Loka. This is situated at the crown of the head. When Kundalini is united with Lord Siva at the Sahasrara Chakra, the Yogi enjoys the Supreme Bliss, Parama Ananda. When Kundalini is taken to this centre, the Yogi attains the superconscious state and the Highest Knowledge. He becomes a Brahmavidvarishtha or a full-blown Jnani.
The word Sahasradala-Padma denotes that this Padma has 1000 petals. That is, one thousand Yoga Nadis emanate from this centre. There are different opinions about the exact number of petals. It is quite sufficient if you know that innumerable Nadis proceed from this centre. As in the case of other Chakras, the vibrations that are made by the Yoga Nadis are represented by the Sanskrit letters. All the 50 letters of the Sanskrit alphabet are repeated here again and again on all Yoga Nadis. This is a Sukshma centre. The corresponding centre in the physical body is in the brain.
