According to ayurveda, the human body is composed of tissues (dhatus), waste (malas), and biomaterials (doshas). The seven dhatus are plasma (rasa), blood (rakta), muscles (māmsa), fat (meda), bone (asthi), marrow (majja), and semen (shukra). Like the medicine of classical antiquity, Ayurveda has historically divided bodily substances into five classical elements, (Sanskrit) panchamahabhuta, viz. earth, water, fire, air and ether. There are also twenty gunas (qualities or characteristics) which are considered to be inherent in all matter. These are organized in ten pairs: heavy/light, cold/hot, unctuous/dry, dull/sharp, stable/mobile, soft/hard, non-slimy/slimy, smooth/coarse, minute/gross, and viscous/liquid.