‘Kala’ can be termed as layer or sheathin the context of anatomy and structural understanding of human body. Locations, enumerations, examples, and clinical utilities of kala are described in ayurvedic classical texts like Sushruta Samhita, Sharangadhara Samhita and Ashtanga Sangraha. Kala can be noticed by their functions in the body. The primary function of kala is to hold, to support or to protect the body components (dhatu) and its related structures.
1 Department of Rachana Sharir, G.J.Patel Institute of Ayurvedic Studies and Research, New Vallabh Vidyanagar, Gujarat, India
2 Rheumatologist, Orlando, Florida, U.S.A.
3 Department of Kayachikitsa, G.J.Patel Institute of Ayurvedic Studies and Research, New Vallabh Vidyanagar, Gujarat, India
|Charak Samhita Research, Training and Development Centre, I.T.R.A., Jamnagar, India
|Date of publication:
|May 18, 2023
The Sanskrit term ‘Kala’ means time, a small part of anything, a symbolic expression for sixteen, and a black or dark color as mentioned in Panini.
A specific tin coating procedure termed as ‘kalyalepa’ or ‘kalai’ is applied on utensils of brass and copper. ‘Kalai’ means white wash or tin. The main purpose of kalai is to prevent utensils from rusting and oxidization. It serves as barrier between food and utensils. Similarly, kala is a barrier between body tissues (dhatu) and organs (ashaya) in the human body.
Definition and development of kala
Kala is the innermost tissue/viscera (dhatu) lining that separates it from the inner cavity (ashaya). It can also be considered as an interface between them. [Su.Sa. ShariraSthana Dalhana 4/4]
The sticky substance (shleshma) between tissue and its lumen (dhatu and ashaya) gets digested by its own dhatwagni and converts into a thin sheath-like structure known as ‘kleda’.[SharangdharaSamhita Purvakhanda 5] The kleda or moisture present in between dhatu and inner cavity(ashaya), reacting to its heat gets converted into kala. Here, the term ‘kala’ refers to a small quantity of essence of tissue (dhatu) or tissue fluid (dhatu rasa) that oozes from it. It is similar with the liquid that oozes from tree after cutting. It envelops muscular tissue (snayu), mucus (shleshma) and serous layer (jarayu). [Ash. Sa. ShariraSthana 5/34]
For a better understanding of kala, it can be correlated with the section of wood, the thin layer that lies in between the core portion of a trunk and the outer thick bark of a tree. Similarly, the section on the fleshy part of the body reveals the internal structure of dhatu. [Su.Sa. ShariraSthana Dalhana4/6] The word ‘snayu’ refers to fibrous sheath, shleshma refers to the mucus membrane, and jarayuas a serous layer. Kala can be correlated with membrane, septum, sheath, layers of the body or cell membrane of each cell.
The topic of kala sharira is elaborated with different examples from the environment to illuminate the ideas and structure of kala. Intellectual visualization and comparative tools can be seen in the kala sharira description.
Number of kala
In samhitas, the total number of kala mentioned is seven. Only slight variation can be seen in their names. [Su.Sa. ShariraSthana Dalhana 4/4], [Ash. Sa. Sharirasthana 5], [Sharangdhara Sa Purvakhanda 5/6]. It is given in table no.1 :
Kala is thin, sheath like structure covered by mucus (shleshma). Anatomically, it is a thin lining of epithelium or mucus membrane (that lines the cavities of viscera) and endothelium (that lines the blood vessels, ducts etc). As the transverse section of the wood shows its innermost tissue separated from the cortex by a thin layer, the same way one can study the structure of kala is by taking a section of tissue (dhatu). [Su.Sa. ShariraSthana Dalhana 4/6]
Kala is differentiated as covered with ligaments (snayupratichhinna), the continuation of fetal coverings (jarayusantata) and coated with mucus membrane (shleshma veshthita). All these structures may or may not be necessarily present in each kala. Even one or two of the above-mentioned structures may be visible in the existing kala. This can be observed in cadaveric dissectionup to a certain extent. [Su.Sa. ShariraSthana Dalhana 4/7]
- Mamsadharakala: The first kala is mamsdhara kala. Within the mamsa dhatu, the network of vessels and nerves (sira&dhamani), tendons or ligaments (snayu), and capillaries (srotasa) are spread. To explain this structure, Sushruta correlated it with the lotus plant, as its stem and roots are firmly embedded in muddy water, similarly, branches of vessels, nerves, and capillaries are embedded in this kala [Su.Sa. ShariraSthana 4/7] [Ash SaSharirsthan. 5/35]. The mamsadhara kala provides anatomical support and forms the protective shield covering of all these delicate structures.[Su.Sa. ShariraSthana 4/7]
Mamsadhara kala includes the innermost layer of skin i.e., dermis (mamsadharatwacha), superficial and deep fascia, intermuscular septum, epimysium, perimysium, and endomysium.
- Raktadharakala/ asrugdhara kala: The second kala is raktadhara kala, which is found mainly in the blood vessels, sinusoids of the liver, and spleen. To elucidate this kala, a perfect simile is latex-yielding trees. If the branches of such trees are cut, we can see the milky sap coming out of them. Similarly, when the incision is given on the body, we can see blood oozing from it. From this, we can state that raktadharakala is located deep within the mams. [Su.Sa. ShariraSthana 4/9-10] [Ash. Sa. ShariraSthana 5/36].
The raktadharakala allows blood to flow through various blood vessels, capillary networks, and sinusoids in the liver and spleen. The tunica intima of blood vessels can be considered raktadharakala.
- Medodhara kala:The third kala is medodhara kala. Medadhatu is present in all individuals, in abdomen and small bones. While large bones contain bone marrow (majja). [Su. Sa. ShariraSthana 4/11] Sushruta identified bone marrow (majja) of two types: red bone marrow (saraktameda) is seen in short bones and yellow bone marrow (peetmajja) is seen in long bones.
Medadhatu is distributed all over the body, especially in the abdomen and small bones. Medadhatu of small bones is called saraktameda. It is red. That within large bones is called peetmajja (yellow). Similarly, the meda dhatu inside the skull bones and brain is called ‘mastulunga’.
Hence, medodhatu is present over the entire body, especially in the abdominal region in the form of omentum, mesentery, and mesocolon. It can also be correlated with the endosteum of the bones.
- Shleshmadhara kala: The fourth kala is known as ‘shleshmadharakala’. It is present in the joints, especially in movable joints (cheshtavanta sandhi). It is compared with the smooth functioning of wheel around its axis. The lubricant achieves this smooth function, allowing the wheel to move around its axis without friction. Similarly, the shleshma with shleshmadhara kala present in the joint facilitates their proper and smooth action. Thus, shleshmadhara kala prevents excessive friction and permits free and smooth movements. This kala can be correlated with synovial fluid and the membrane of the joints.
- Purishadharakala: The fifth Kala is purishdhara kala, also known as maladhara kala. In Sharangadharasamhita, this kala is called antradharakala. This kala includes the viscera surrounding the liver, the biliary apparatus (yakrutasamantat), and small and large intestines. The purishdhara kala lies in the large intestine (pakwashaya), predominantly in the caecum (unduka). This part separates fecal matter (mala) and chyle (ahara rasa). The primary role of maladhara kala is the segregation of water and other essential and non-essential materials. [Su.Sa. ShariraSthana 4/16-17]
This kala can be correlated with mucosal membrane of the gastro-intestinal tract.
- Pittadharakala:The sixth kala is pittadharakala. It receives all four kinds of food; ashita(chewed), khadita(swallowed), peeta(drinks), and leedha(licked) from mouth to the stomach. It retains the food until its complete digestion in proximal part of the digestive tube up to the ileum. Further, the digested food is propelled toward the larger intestine. This digestion and absorption of food in a given time is accomplished by pachakapitta in pittadharakala. [Su.Sa. ShariraSthana 4/18-19] The pittadhara kala site is between the stomach (amashaya) and the large intestine (pakvashaya). This part of annavaha srotasa is known as ‘grahani’.
This kala can be correlated with the epithelium of digestive glands, enzymes, mucous membrane of the digestive tube, its villi, and lacteals responsible for digestion.
- Shukradharakala:The seventh Kala is shukradhara kala, present all over the body of all living beings. Jaggery and ghee are present in the sugarcane juice and milk, respectively, but it is difficult to identify their presence. Similarly, the shukra is present in the entire body, and it can be understood only by its function. Semen is ejaculated through the male urethra during coitus. Shukradhara kala can be correlated with the inner lining of the seminal vesicle, ejaculatory duct, vas difference, epididymis and seminiferous tubule in the testis.
It is difficult to quote references to shukradhara kala in females as observed in Ayurveda texts. But it may be correlated with the development of anasthigarbha (boneless embryo) formed by ejaculation in females only. It is mentioned in Shukrashonita Shuddhi ShariraAdhyaya.[Su. Sa. ShariraSthan 2/49]
Importance of kala in the prevention and preservation of health
The primary functions of kala are protection, secretion, and absorption.
The epidermis and dermis layer of skin, superficial and deep facia, and intermuscular septa can be considered mamsadhara kala. These structures protect and envelop the underlining tissues, muscles, vessels, nerves, organs, glands etc.
The omentum, mesentery, and mesocolon are considered medodharakala. In contemporary science, the omentum is the policeman of the abdomen. Similarly, the medodhara kala works as the protective layer of abdominal viscera. And also, the endosteum and periosteum, the protecting layer of bone, can be correlated with medodhara kala.
The synovial membrane and fluid within the movable joint prevent friction during its movement and protect the articulating ends of bones.
The mucus membrane of the gastrointestinal tract protects the submucosal and muscular layer from hydrochloric acids and other digestive enzymes.
Similarly, the meninges, pleura, and pericardium act as shock absorbers and protect the vital organs, brain, lungs, and heart. Also, we may consider the endometrium and hyaloid membrane of the eyeball in this context.
The pleural fluid is secreted by the mesothelial cells of the pleura, the pericardial fluid by the serous layer of the pericardium, the peritoneal fluid by its serous layer, digestive juices and enzymes, cerebrospinal fluid secreted by choroid plexus, all these can be considered as secretions of various kala.
The arachnoid villi and granulation of arachnoid matter absorb CSF from subarachnoid space. Similarly, the digested food (chyle) is absorbed from the intestinal villi.
Preservation of health of kala and its treatment guidelines
In healthy conditions, the kala prevents our body from various disorders. A few examples are stated below,
- In intestinal perforation, the omentum seal that specific area, thus preventing the oozing of intestinal contents and avoiding further complications. The peritoneum protects abdominal viscera from various infections as there is the presence of abundant lymphoid follicles
- In partial splenic rupture, the peritoneum covers the affected area and prevents bleeding.
- The mucosal layer of the gastrointestinal tract has the specific peculiarity of profuse proliferation that helps to reduce the deepening of ulcers.
- The fibrous layer of pericardium prevents excessive expansion of myocardium and reduces the chances of cardiomegaly.
- The recesses of pleural cavity; the costodiaphragmatic and costomediastinal recesses provide dead space for lung expansion during inhalation.
- The synovial fluid nourishes articular cartilage and prevents its degeneration.
- The deep facia provides the additional surface area for the attachment of muscle fibers to increase muscle mass and strength.
- The hyaloid membrane in the posterior segment of eyeball contains vitreous humor. It maintains particular pressure that prevents retinal detachment.
- The gut flora maintains a healthy environment for better digestion and absorption.
- The innermost endometrium lining of the uterus shows cyclical changes that lead to forming a bed for the implantation and nourishment of the developing fetus.
Application of kala in agada tantra (forensic medicine and toxicology)
The snake poison successively attacks the seven kala and gives rise to seven poisoning stages. The patient's prognosis with the snake bite depends on the presence of toxin in the respective kala. [Su. Ka.4/39]
In the first phase, the poison vitiates blood, due to which it becomes black and hence causes blackening of skin and feeling as ‘ants are crawling on the body’.
In the second phase, it vitiates muscles, which gives rise to marked blackness, inflammation, and cyst in the body.
In the third phase, it vitiates fat which causes moistening of the bite site, heaviness of the head, and stiffness of eyes. In the fourth phase, the poison enters the thoraco-abdominal cavity. It vitiates dosha, predominantly kapha, which produces drowsiness, salivation, and weakness in joints.
In the fifth phase, it further penetrates bones. It vitiates prana and agni, leading to joint pain, hiccoughs, and a burning sensation. In the sixth phase, it reaches the bone marrow. It highly vitiates the small intestine (grahani) which gives rise to heaviness in the body, diarrhea, cardiac pain, and fainting. In the seventh phase, it enters into semen (shukra) and highly vitiates vyanavayu. It causes the discharge of kapha from minute channels, leading to breaking pain in the waist and back, loss of all movements, excessive salivation and sweating, and finally, death due to respiratory arrest. [Su.Sa.KalpaSthana4/39]
As the snake venom passes deeper into various tissues (dhatus) by piercing several kalas, the patient's prognosis become more and more critical.
In corelation with contemporary science the term kala can be corelate with various serous or mucosal membranes. Mamsadhara kala includes the innermost layer of skin i.e., dermis (mamsadharatwacha), superficial and deep fascia intermuscular septum, epimysium, perimysium, and endomysium. The raktadhara kala allows blood to flow through various blood vessels, capillary network, and sinusoids in the liver and spleen. The tunica intima of blood vessels can be considered raktadhara kala. Medodhatu is present over the entire body especially it is appreciated in the region of abdomen in the form of omentum, mesentery, and mesocolon. It can also be correlated with the endosteum of the bones.
Similarly the shleshmadhara kala can be correlated with synovial fluid and membrane of the joints. Purishadhara kala can be correlated with mucosal membrane of the gastro-intestinal tract especially in the region of large intestine. The pittadharakala can be correlated with the epithelium of digestive glands, enzymes, mucous membrane of the digestive tube, its villi, and lacteals responsible for digestion. Shukradhara kala can be correlated with the inner lining of the seminal vesicle, ejaculatory duct, vas difference, epididymis, and seminiferous tubule in the testis.
Future scope of research in kala sharira
From the treatment point of view, the knowledge of kala sharira proved to be of utmost importance as the site beholds the specific organ. It also reflects the effect on dhatu. Intestinal resection may lead to certain disorders, such as improper digestion and poor absorption of nutrients.Hence it may cause loss of bone density and affect physical and mental health. To reduce such complications, tiktakshirabasti(enema with medicated milk and ghee) may be beneficial. The various psychological disorders can affect the enteric nervous system closely related to pittadharaand purishdhara kala. So, in such cases, psychological consideration should be at its utmost priority. Hence it can be concluded that there is wide scope for research to study cellular changes at the level of kala with the use of modern technologies.
- Vaman ShivramApte. The practical Sanskrit-English dictionary. Bhartiya GranthaNiketan : New Delhi.page 342
- Available from https://en.wikipedia.org/wiki/K%C4%81la#cite_note-FOOTNOTEDalal2011185-3
- History of Tin-coating of Metallic Utensils in India | INTACH Intangible Cultural Heritage