<prompt> The amount of blood loss during each menstrual period is about:10 cc35 cc50 cc100 cc  <response>: Menstrual blood is predominantly aerial, with only 25 of the blood being of venous origin. It contains tissue debris, prostaglandins, and relatively large amounts of fibrinolysin from the endometrial tissue. The usual duration of the menstrual cycle is 3-5 days. The average amount of blood loss is 30 mL. Loss of more than 80 mL is abnormal. Ref: Alford C., Nurudeen S. 2013. Chapter 4. Physiology of Reproduction in Women. In A.H. DeCherney, L. Nathan, N. Laufer, A.S. Roman Eds, CURRENT Diagnosis Treatment: Obstetrics Gynecology, 11e. 