The last and 3rd principle or dosha of tirdosha sidhhanta is Kapha dosha. When we plant a seed, it needs sunlight (Agni tatva) and air(oxygen/ vaayu tatva) along with water(som tatva) and if all three are in appropriate amount , It leads to healthy growth. Similarly in human body for growth, or for regeneration kapha dosha is responsible which we can call soma tatva of human body.
According to ayurveda vaata dosha consists of vaayu mahabhuta mainly, Pitta dosha consists of Agni (fire) and Jal (water) mahabhuta and in kapha dosha there is dominance of Prithvi (earth) and Jal (water) mahabhuta , and because of Prithvi and Jal elements our body get its firmness, rigidity and ability to regenerate.
According to ayurveda vaata dosha consists of vaayu mahabhuta mainly, Pitta dosha consists of Agni (fire) and Jal (water) mahabhuta and in kapha dosha there is dominance of Prithvi (earth) and Jal (water) mahabhuta , and because of Prithvi and Jal elements our body get its firmness, rigidity and ability to regenerate.
