What keeps us from bleeding out when we scrape our knee or sustain severe injuries? As we speak, the coagulation cascade, an intricate and highly regulated cascade of proteins and cofactors are at play (along with platelets!) as blood flows throughout our vascular system. When these systems are disrupted, we can have excessive bleeding or formation of clots. This study guide covers the coagulation cascade, clotting disorders such as hemophilia, blood transfusion basics, and the pathology of gunshot wounds.