Though the English translation of the Sanskrit word Dhatu as ‘body tissue’ does not convey all the subtleties of its meaning, it is used here in that sense. According to the Indian science of health, the Dhatus or body tissues are formed from and nourished by the Ahaara Rasa (essence of food).
1. Rasa Dhatu (plasma)
Rasa Dhatu, the first in the sequence of the seven Dhatus, is formed by the action of the digestive fire on the Ahaara Rasa. The function of the Rasa Dhatu is to strengthen the Rakta and help nourish the entire body.
2. Rakta Dhatu (blood)
Rakta Dhatu is formed by the metabolic refinement of Rasa Dhatu. The chief functions of Rakta Dhatu are the nourishment of the body and the preservation of life.
3. Mamsa Dhatu (muscle)
The Mamsa Dhatu, which covers the bones and gives strength to the body, is formed from each of the Rasas and the Rakta Dhatu.
4. Meda Dhatu (fatty tissue)
The finer parts of the Mamsa Dhatu are transformed into Meda Dhatu (fatty tissue).
5. Asthi Dhatu (bone)
The finer essence of the Meda Dhatu is converted into the most solid form of the Dhatus – the asthi or bone.
6. Majja Dhatu (bone marrow)
The finer essence of the Asthi Dhatu which is a semi- solid substance becomes Majja in the process of metabolism.
7. Sukra Dhatu (semen / ova)
Sukra, the seventh and last of the Dhatus is produced from the most refined essence of the Majja Dhatu. It is the cause of Ojas, which may be called the essence of all the seven Dhatus. It is responsible for vitality and energy.