INTRODUCTION TO DHATU –
Dhatu are the elementary tissues of the human body. Dhatus are building blocks of body, they are seven in numbers. It occupies much wider scope of Dosa-Dhatu-Mala-Vijnana and represents the physiology of basic nutritional and structural factors of the body.
NIRUKTI OR DERIVATION OF DHATU –
The term dhatu is formed with the help of डुधाम–धारणपोषणयोः , which conveys dharana and poshana, means which bears and nourishes the body.
It is formed by ‘धा’ dhatu and ‘तुमुन्’ प्रत्यय.
LAKSHANA OR DEFINITION OF DHATU –
शरीरं धारयन्त्येते धात्वाहारश्च सर्वदा | (अ.सं.सू. -1/29)
According to Astanga Sangraha Dhatus always bears the body & one dhatu provides nourishment for the next dhatu.
NUMBERS OF DHATUS AND THEIR NAMES –
There are seven Dhatus(सप्त धातु ) viz.-
- Ras Dhatu – Body fluids and Plasma
- Rakta Dhatu – Blood cells
- Mansa Dhatu – Muscles
- Meda Dhatu – Adipose Tissues
- Asthi Dhatu – Bone
- Majja Dhatu – Bone marrow
- Shukra Dhatu – Male and Female gametes and Reproductive hormones.
DHATU SAMANYA KARYAS OR ITS FUNCTIONS–
प्रीणनं जीवनं लेपं स्नेहो धारणपूरणे गर्भोत्पदश्च धातूनां श्रेष्ट कर्मे क्रमात् स्मृतम् | (अ.ह.सु 11/4)
Nourishment of the body, mantaining the life, enveloping the body, lubrications in the body, supporting the body, filling and formation of the garbha are the srestha karyas of the dhatus.
FORMATION OF DHATUS:-
रसाद्रक्तं ततो मांसं मांसान्मेदो ततो अस्थि च।
अस्थनो मज्जाः ततः शुक्रं शुक्राद् गर्भ प्रजायते ।।
In Sushrut Sutrasthana acharya Sushruta mentioned that function of each dhatu is to nourish their consecutive dhatu and help in the formation of it. It has been unanimously agreed upon by all the ancient authorities that production of sapta dhatus follows a kind of progressive evolutional metamorphosis i.e. Rakta dhatu is developed and nourished by rasa dhatu.The process of nourishment and development of the sapta dhatus go in a particular sequence
Rasa Rakta ………….. Majja Shukra
Dhatu as well as malas in vitiated condition are known as Dushyas.
रससृङ्गमांसमेदास्थि मज्ज्शुक्राणि धातवः।
सप्त दुष्याः मला मूत्राशकृत्स्वेदादयोSपि च ।। (अ. हृ. सु. 1 /13)
Ras ,Rakta ,Mansa ,Meda ,Asthi ,Majja and Shukra Dhatus while Shakrit (faeces) , Mutra (urine) and Sweda (sweat) are three malas. Seven dhatu and three malas when get vitiated by vatadi dosha are called as dushya.