Prothrombin and fibrinogen are substances  that  make  you stop bleeding when you cut yourself. This process is called blood clotting.

The liver also makes heparin and anti-thrombin which controls blood flow. Your blood carries hormones as well.

Hormones are chemicals that play a large part in many of our daily functions as well as critical life milestones. Hormones affect everything from blood sugar to blood pressure, growth, metabolism, and even sleep.

The liver stores vitamins A, D,  E, K, B12 and iron. Your liver uses Vitamin K to help blood clotting. 

Your liver can take bacteria and other germs that make you sick out of your blood.