Dhatus are seven basic
supporting structures of the human body formed by food. Our
bodily tissues are continuously formed, destroyed and reformed in the body,
using materials derived from the food and drinks we take in. When all the
stages of digestion are functioning properly, and our digestive fire (agni) is balanced, we are able to build
the tissues that make up the structure of our body and which support and
maintain us.
The
dhatus consist of Rasa (which can be
considered a vital fluid resembling plasma), Rakhta (blood), Mansa
(muscle), Meda (adipose tissue), Asthi (bone and cartilage), Majja (bone marrow, the fatty part), and
Shukra (reproductive tissue, ovaries,
eggs, semen). These dhatus must not be considered to correspond completely with
plasma, blood etc., but should be considered on their own terms.
Dhatu are formed by aharasa,
the substance first created after food has been metabolised. Ahar literally means food or ´intake´.
Food or ´intake´ is metabolized by ´agni´,
´fire´, an Ayurvedic concept which I will consider in detail in another post. First,
food is metabolised by Jatharagni (literally
the ´fire´ in the stomach which breaks down raw materials into rasa), and second, by the five Bhootagni in the liver (ie the ´fires´
of ether, air, fire, water and earth which metabolise the corresponding
property of foodstuffs). Finally, each dhatu
has its own corresponding dhatvagni (therefore
7 dhatvagni) which sorts the previous
dhatu´s apportation into useful
nutrition for its own dhatu and mala (waste) to be expelled.
These seven major dhatu form sequentially, each building on the one that came before
it, (although in principal each dhatu may also able to take what it needs from
circulating rasadhatu). In other
words the dhatu are nourished in two
ways. The first way, the principle of overflow, suggests that aharasa must be of sufficient quantity
and quality to satisfy the requirements of circulating plasma before the subsequent
dhatu, raktadhatu can be nourished. Then raktadhatu must be well nourished, in order for mamsadhatu to form properly. We can
imagine the classic image of abundance of the pyramid of champagne glasses,
where the champagne overflows from the top glass into the second, third and
subsequent layers. All layers depend on the previous one to be filled to
capacity and overflow.
However we must remember
that this process is ongoing as the body continues to ingest food and use it to
make aharasa, allowing all cellular
processes to take place. Rasa is in each cell, as is ´agni´. Each dhatu is made up of innumerable paramanu (cells) which both receive
nutrients and expel waste. Sukshma strota
are tiny pathways throughout the body (for example leading to the pores of
the skin)
How does this work exactly? Each dhatu generates ' prasada' , literally food or
nutrition which forms the subsequent dhatu.
Each is produced sequentially, one after another, so if there is a breakdown
early on in the process of tissue formation, then it affects all other tissues
in the body. Because our vitality, immunity and strength (ojus, the essence of nourishment, or
what is left when aharasa has been
absorbed by lesser dhatu and all
wastes have been removed) is only produced at the end of the cycle, it is
essential for our overall health that the tissue formation process is
functioning properly. You may also note that the reproductive system is the
last tissue system to be nourished, so when someone is having problems
conceiving, ultimately, an improper digestive system or lack of proper nourishment
may be the root of the problem.
Ahar forms Aharasa, the raw material of nutrition
and preliminary Rasadhatu within a
day or two. Raktadhatu takes betwen 7
and 10 days to form, Mamsadhatu
between 14 and 20 days, Medadhatu 5
to 7 days, Asthidhatu 7-10 days, Majjadhatu 7-0 days and Shukradhatu between 30 and 72 days. Marma, Asthi , Sandhi (the latter
´joints´) being the deepest tissues, take longer to be nourished. Note the
order of the depth of the tissues. If you scratch the skin, first simple fluid
is seen, then later blood. If you were to penetrate further into the body you
would pass through fat and muscle to the tendons and bones. At the deepest
levels we find bone marrow and reproductive tissue.
If
rasadhatu is malnourished you will
see the consequences quickly, in terms of dehydration, skin, eye and tongue
dryness, weakness, dizziness etc. If shukradhatu
is affected it will take much longer. For example skin will dry out in a matter
of hours due to a lack of fluids, but amenhorrea tends to occur after months of
extreme malnutrition, eating disorders etc.
Medadhatu circulates as fat
globules in aharasa and has a unique
blocking quality, tending to block the strota,
causing later malnutrition as nutrients cannot get through to support deeper
tissues. It can be seen as cholesterol in the blood, yellow motes in the eyes,
fatty liver, etc and explains why someone can appear well nourished, overweight
or obese but when nutritional levels are checked they are in fact malnourished.
When medavahastrota is blocked by ama we tend to see overweight, alongside
badly nourished dhatu, so feelings of
heaviness, tiredness, lack of appetite and energy, and cravings are common.
