The hematological system is considered the system of the body that regulates the movement of nutrients, molecules (macro and micro molecules), and oxygen into the tissues and metabolic waste products and carbon dioxide out of the tissues (Colbert, 2009). The overall role of the hematological system is to provide substances necessary for cellular metabolism, temperature regulation, defend the body from microbial injury and infection, and maintain homeostatic balance or blood acid-base chemistry and fluid balance -electrolytic. The hematological system consists mainly of blood, blood vessels, and primary organs that produce blood cells such as the bone marrow, spleen, lymph nodes, liver, and thymus gland (Ignatavicius & Workman, 2009). Blood is made up of three distinct components: red blood cells, white blood cells and plasma and its role is to transport the substances necessary for metabolism (nutrients, hormones and oxygen) to the cells and to remove metabolic waste products and carbon dioxide, regulating body temperature and fluid balance and protecting the body from infections. Blood vessels simply help transport blood throughout the body, simply in and out of the heart. The spleen for its part is the largest lymphatic organ and functions as a blood filtration system and reservoir, a site for fetal hematopoiesis and activates immune responses that act against invasive infections. The bone marrow is another important component of the hematological system and its role is to synthesize new blood cells (red blood cells, white blood cells and platelets) that make up a healthy blood count while the liver functions by detoxifying the blood (Colbert, 2009). .Folic acid deficiency is a metabolic disorder characterized respectively by the lack of... half of paper... In terms of evaluation, hemophilia is suspected in children with excessive bleeding, easy bruising, spontaneous hematuria, and epistaxis (Ignatavicius & Workman, 2009). A low prothrombin level and bleeding and a low factor VIII are indicative of hemophilia A, while a prolonged thromboplastin time and low factor IX are indicative of hemophilia B. Hemophilia is a lifelong disease and treatment regimens aim to reduce the signs and symptoms associated with it. Types A and B are managed with factor VIII and factor IX plasma concentrate supplementation, liver transplantation, and gene therapy, respectively (Colbert, 2009). Works Cited Colbert, B. (2009). Anatomy, physiology and disease. Kendallville: Pearson.Ignatavicius, D. & Workman, L. (2009). Medical-Surgical Nursing, 6th Edition. New York: Saunders.