Changes

[[Dhatu]]s are the structural and functional units that act as [[dosha]] and [[mala]] seats. The functioning of dhatvagni (dhatvagnipaaka) includes overall nourishment and development of the body structures. Dhatvagnipaaka refers to the sequential changes undergone by the essence of food through the medium of seven dhatvagni entities.

[[Dhatu]]s are the structural and functional units that act as [[dosha]] and [[mala]] seats. The functioning of dhatvagni (dhatvagnipaaka) includes overall nourishment and development of the body structures. Dhatvagnipaaka refers to the sequential changes undergone by the essence of food through the medium of seven dhatvagni entities.

[[File: Fig_1_Datu_agni.JPG|500px|'''Figure 1: Action of different agnis on their respective dhatus and their products '''|thumb]]

[[File: Fig_1_Datu_agni.JPG|500px|'''Figure 1: Action of different agnis on their respective dhatus and their products '''|thumb]]

The seven dhatvagni act upon the respective [[dhatu]] by which each [[dhatu]] is metabolized into two parts i.e., essence (prasada bhaga) and by-products (mala bhaga). [Chakrapani on Cha.Sa.[[Chikitsa Sthana]] 15/15] [[Dhatu]] is metabolized by their inherent heat (ushma) or dhatvagni (transforming enzymes in the tissue elements). The nourishing fraction of [[dhatu]] (nutrient tissue elements) further nourishes the subsequent [[dhatu]] through their respective [[srotas]] (channels of circulation). For example, a poshaka [[rasa dhatu]] nourishes the [[rakta dhatu]].[Cha.Sa.[[Chikitsa Sthana]] 8/39] In this process, the formation of essence (prasad bhaga) can be correlated with anabolic pathways. The formation of metabolic wastes or by-products (kitta-paka) can be correlated with catabolic pathways.

The seven dhatvagni act upon the respective [[dhatu]] by which each [[dhatu]] is metabolized into two parts i.e., essence (prasada bhaga) and by-products (mala bhaga). [Chakrapani on Cha.Sa.[[Chikitsa Sthana]] 15/15] [[Dhatu]] is metabolized by their inherent heat (ushma) or dhatvagni (transforming enzymes in the tissue elements). The nourishing fraction of [[dhatu]] (nutrient tissue elements) further nourishes the subsequent [[dhatu]] through their respective [[srotas]] (channels of circulation). For example, a poshaka [[rasa dhatu]] nourishes the [[rakta dhatu]].[Cha.Sa.[[Chikitsa Sthana]] 8/39] In this process, the formation of essence (prasad bhaga) can be correlated with anabolic pathways. The formation of metabolic wastes or by-products (kitta-paka) can be correlated with catabolic pathways.

   

   

==Importance of concept of dhatvagni in physiology==

==Importance of concept of dhatvagni in physiology==

[[File: Fig_3_Datu_agni.JPG|500px|'''Figure 3: Process of Formation of different Dhatus '''|thumb]]

[[File: Fig_2_Datu_agni.JPG|500px|'''Figure 3: Dhatvagnipaka (intermediate metabolism)- Synthesis of constituents of sthayi (poshya) dhatu '''|thumb]]

Dhatvagni, in general, represents the process of tissue metabolism and assimilation. Different types of wholesome foods ingested in the form of eatables, drinkables, lickables and masticables stimulate digestion (antaragni). They are further digested by respective bhutagni (specific digestion per primary constituent or element). In due course of time, food gets transformed into different [[dhatu]] in the presence of dhatvagni (tissue-specific digestion and metabolism) [A.H.Sharira Sthana 3/62]<ref name=Hridaya/> and [[vata]] (vyanavayu) by the process of dhatvagnipaka. [A.S.Sharira Sthana 6]<ref name=Sangraha/> It nourishes the tissues through channels of circulation without interruption and produces plumpness, strength, complexion, health, and longevity. The tissues are sustained by getting fed by various nourishing factors (poshaka dhatu). Thus, it plays a vital role in maintaining the digestive physiology and assimilation in the body. [Cha.Sa.[[Sutra Sthana]] 28/3] Therefore, the whole genesis, metabolism, functioning and elimination of [[dhatu]] are dependent on this process of dhatvagnipaaka. [Cha.Sa.[[Sutra Sthana]] 28/3] Hence, it is the basis of the ksheeradadhinyaya (law of complete transformation of one substance to other like milk into curd) and kedarikulyanyaya (sequential transformation of tissues just like canals in a farm). This depicts the [[dhatu]] metabolism. [Chakrapani on Cha.Sa.[[Chikitsa Sthana]] 15/16] Thus, the systematic nourishment of [[dhatu]] (dhatusnehaparampara) is maintained through dhatvagni. [Cha.Sa.[[Chikitsa Sthana]] 15/19][Arunadatta on A.H.Sharira Sthana 3/70]<ref name=Hridaya/>

Dhatvagni, in general, represents the process of tissue metabolism and assimilation. Different types of wholesome foods ingested in the form of eatables, drinkables, lickables and masticables stimulate digestion (antaragni). They are further digested by respective bhutagni (specific digestion per primary constituent or element). In due course of time, food gets transformed into different [[dhatu]] in the presence of dhatvagni (tissue-specific digestion and metabolism) [A.H.Sharira Sthana 3/62]<ref name=Hridaya/> and [[vata]] (vyanavayu) by the process of dhatvagnipaka. [A.S.Sharira Sthana 6]<ref name=Sangraha/> It nourishes the tissues through channels of circulation without interruption and produces plumpness, strength, complexion, health, and longevity. The tissues are sustained by getting fed by various nourishing factors (poshaka dhatu). Thus, it plays a vital role in maintaining the digestive physiology and assimilation in the body. [Cha.Sa.[[Sutra Sthana]] 28/3] Therefore, the whole genesis, metabolism, functioning and elimination of [[dhatu]] are dependent on this process of dhatvagnipaaka. [Cha.Sa.[[Sutra Sthana]] 28/3] Hence, it is the basis of the ksheeradadhinyaya (law of complete transformation of one substance to other like milk into curd) and kedarikulyanyaya (sequential transformation of tissues just like canals in a farm). This depicts the [[dhatu]] metabolism. [Chakrapani on Cha.Sa.[[Chikitsa Sthana]] 15/16] Thus, the systematic nourishment of [[dhatu]] (dhatusnehaparampara) is maintained through dhatvagni. [Cha.Sa.[[Chikitsa Sthana]] 15/19][Arunadatta on A.H.Sharira Sthana 3/70]<ref name=Hridaya/>