Since Ayurveda recognizes a common origin for the universe and for humanity, Ayurveda teaches that nature consists of three primary qualities called gunas. These three gunas – Sattva, Rajas and Tamas – are inner qualities that exist behind all material forms in nature. Another great theory is of the five gross elements (Panchamahabhutas) – space, air, fire, water, and earth – and that the entire universe is governed and composed of these five elements. The entire physiology is made up of seven tissues (Dhatus) – plasma, blood, muscle, adipose tissue (fat), bone, bone marrow, and reproductive tissue. From the sap of all tissues, Ojas, the ultimate refined product of digestion and metabolism, which connects one’s physiology with consciousness and is responsible for greater immunity, is formed.