Key Points. 1  Megaloblasts are large nucleated RBC precursors with noncondensed chromatin. 2  The most common causes of megaloblastic, macrocytic anemia are deficiency or defective utilization of vitamin B12 or folate. 3  Do CBC, RBC indices, reticulocyte count, and peripheral smear.
vein. 1. Any of the blood vessels that carry blood toward the heart. Veins are thin-walled and contain valves that prevent the backflow of blood. All veins except the pulmonary vein (which returns to the heart from the lungs) carry blood having low levels of oxygen. 2.
Superficial vein. Superficial vein is a vein that is close to the surface of the body. This differs from deep veins that are far from the surface. Superficial veins are not paired with an artery, unlike the deep veins, which typically have an artery with the same name close by. Superficial veins are important physiologically for cooling of the body.