The liver is the main hematopoietic organ at 8-12 weeks of embryonic life. The liver still has hematopoietic functions in newborns and stops producing blood when they grow up. However, the liver has a variety of important physiological functions, such as metabolic functions, detoxification functions, bile production and secretion functions, coagulation functions, immune defense functions, blood storage and regulation of circulating blood volume. The liver has a large blood flow and a large blood volume, like a blood reserve that can provide some of the blood when needed by other organs in the body. For example, if a person has a gastrointestinal hemorrhage, the blood volume drops sharply and vital organs such as the heart, brain and kidneys cannot withstand the ischemia, the liver can divide some of the blood to supply the heart, brain and kidneys, but at the cost of the liver being prone to ischemic liver injury.