Temporal platelet

Temporal platelets were a part of the bloodstream of Time Lords. They were the reason that the Doctor usually recovered more quickly than humans from most injuries. As the Fifth Doctor told Erimem on Peladon, "When a Time Lord is injured or close to death, temporal platelets coalesce around the wound. Full body regeneration is a costly process, so ad hoc repairs are the norm." (AUDIO: The Bride of Peladon)