So, I am relearning the coagulation cascade and am confused about which steps require calcium and or phospholipids to take place. I am looking in my copy of Robbins and the diagram shows only two steps that require both phospolipids and calcium, while a few others just require calcium. However, first aid shows a bunch more as requiring both phopholipids and calcium. My old class notes don't correspond to either...I was wondering what the generally accepted set of phospholipid and/or calcium containing reactions were or if it's even important to know this...