A Comprehensive Study of Udakvaha Srotas With Special Reference to Approach for Structural Determination of "Kloma"

Background: Ayurvedic classical literature describes Udakvaha Srotas as the channel system responsible for the regulation, distribution, and maintenance of fluid homeostasis in the human body. Talu (palate) and Kloma are identified as the Mula Sthana (root structures) of Udakvaha Srotas. While Talu has been correlated with the neurosensory perception of thirst, Kloma remains one of the most controversial and enigmatic organs in Ayurvedic anatomy, with no consensus on its precise structural identity. Objective: The present article aims to conduct a comprehensive review of Udakvaha Srotas with special emphasis on various approaches for the structural determination of Kloma, integrating classical Ayurvedic perspectives with contemporary anatomical and physiological understanding. Methods: A structured narrative review was conducted by systematically examining primary Ayurvedic literature including Charaka Samhita, Sushruta Samhita, and Ashtanga Hridaya, along with commentaries by Chakrapani, Dalhana, Gangadhara, and Arunadatta. Modern biomedical literature was retrieved from PubMed, Scopus, and Google Scholar using keywords: "fluid homeostasis," "hypothalamic thirst centre," "microvascular exchange," "pancreas anatomy," "lymphatic system," and "pleural physiology." Results: Multiple hypotheses regarding the structural identity of Kloma have been proposed, including correlation with the pancreas, lungs, pharynx, trachea, lymphatic system, suprarenal glands, and neuroendocrine thirst centres. The analysis reveals that Kloma may represent a functional conglomerate rather than a single discrete organ, integrating thoracic structures involved in fluid regulation. Conclusion: The structural determination of Kloma requires a translational approach that transcends reductionist one-to-one correlation. Kloma appears to represent a functional anatomical zone encompassing the mediastinal structures involved in fluid balance, thirst regulation, and kapha metabolism, thereby positioning Udakvaha Srotas as a distributed macrovascular-microvascular regulatory network.