Platelets, also called thrombocytes (thromb- + -cyte, blood clot cell), are a component of blood whose function (along with the coagulation factors) is to stop bleeding by clumping and clotting blood vessel injuries.
Milk of the poppy is essentially the Westeros version of morphine. Maesters make it from crushed poppy flowers, and morphine and other opiate-based drugs are made from poppy plants. Indeed, the books' descriptions strongly suggest that the poppy is intended to be the real-world opium poppy (Papaver somniferum).
Poppy seeds contain both Morphine and Codeine and can cause false positives for Opiates in urine tests. Most Opiate urine tests have a cut off level of 300 ng/ml.Ingestion of a single poppy seed bagel can produce an opiate level somewhere around 250 ng/ml three hours later. teaspoons of store bought poppy seeds can result in 1200 ng/ml 6 hours later (1). We have read an estimate that 70% of DOT opiate positives are from poppy seeds. The U.S. Military uses cut off levels of 3000 ng/ml in order to minimize false positives.