The prāṇamayakośa, or the "vital air" layer or body, is composed of five different forms that vital energy assumes, according to its movement and direction within the body.

This is an important topic, not only for Yoga but also for Āyurveda, the Indian science of health and longevity. These five forms of vital energy are called vāyus or prāṇas. They are:

Prāṇa: Prāṇa literally means 'forward-moving force'. It regulates all absorption processes, including the inhalation movement, assimilation of solid and liquid foods, and reception of sensory impressions.

It is centripetal by nature and serves the purpose of setting things in motion. It is located in the upper chest, between the throat and the navel.

Samāna: Samāna literally means 'balancing vital air'. It moves in a circular manner, from the periphery to the center, in the middle region of the abdomen, between prāṇa and apāna.

Samāna assists in digestive processes at all levels. It works on the gastrointestinal tract for food digestion, the lungs for oxygen absorption, and the mind for assimilation of sensory, emotional, or mental experiences.

Vyāna: Vyāna literally means 'outward-moving vital air'. It moves from the center to the periphery, between the trunk and the limbs.

Vyāna controls all levels of circulation: it moves nutrients in the body, feelings and thoughts in the psyche, the administration of willpower, and the coordination of the other four prāṇas.

Udāna: Udāna literally means 'expulsive vital air'. It governs the growth of the body, the ability to stand, speak, exert, and get enthused.

It regulates the distribution of vital energy in the throat region. On the subtle plane, it regulates movements of positive transformation and evolution of our existence.

Apāna: Apāna literally means 'downward-moving vital air'. It controls all processes of excretion (semen, urine, and feces) and elimination (elimination of carbon dioxide in respiration, menstruation, and childbirth).

Due to its expulsive function, apāna is responsible for the proper functioning of the immune system. On a subtle level, it regulates the expulsion of negative, emotional, and mental experiences.

Apāna moves centrifugally, downward and outward, and is located in the lower abdomen.

In summary, prāṇa regulates substance absorption, samāna regulates digestion, vyāna regulates circulation, udāna regulates the release of vitality and/or nutrients of these substances, and apāna regulates the elimination of the waste they may leave behind.

Lots of Love,
Marco Vasconcelos