Concepts of Human Physiology in Ayurveda

Abstract

‘Human Physiology’, or the study of functional aspects of human body, is designated by the term ‘Śarīra Vicaya’ in Ayurvedic literature. The word ‘Vicaya’ means the special or detailed knowledge. Detailed knowledge of normal human body i.e., ‘Śarīra’, is considered helpful in understanding the factors influencing the health. Though most of the basic concepts of human physiology explained in Ayurveda are strikingly similar to the concepts of modern physiology, some concepts like ‘Ātmā’, ‘Manas’ and ‘Prakrti’ are unique to Ayurveda. Understanding of Physiology in Ayurveda should start with the understanding of innumerable minute individual living units called ‘Śarīra Paramānus’ or ‘Anu Srotāmsi’. These units are now known as cells. A group of such functionally and structurally similar units is called a ‘Dhātu’. These ‘Dhātus’ are almost equivalent to the tissues. Seven such ‘Dhātus’ have been enumerated. Similarly, the individual systems in the body have been designated by the term ‘Sthūla Srotāmsi’ and thirteen such ‘Srotāmsi’ have been described by Caraka. ‘Annavaha Stotas’, for example, stands equivalent to the digestive system and ‘Rasavaha Srotas’ to the cardio vascular system. Apart from these, the functioning of individual systems has also been described in a considerably detailed manner. Cardiovascular system as a closed circuit, role of liver in the functioning of hemopoietic system, functional significance of brain in the neural mechanisms, basics of digestion and metabolism and basics of immunity ‐ are some such topics worth mentioning. Theory of ‘Tridosha’ is another important theory of physiology. This represents the various reciprocally functioning homeostatic mechanisms at various levels of organization. The state of equilibrium among these ‘Doshas’ is responsible for maintenance of health. Three ‘Doshas’ – i.e., ‘Vāta’, ‘Pitta’ and ‘Kapha’ in general, represent neural, endocrine and immune mechanisms respectively and form the basis of neuro‐ immuno‐ endocrinology.