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 (noun). a train of association, thoughts, emotions, or the like; a current; a course. Vein (noun). peculiar temper or temperament; tendency or turn of mind; a particular disposition or cast of genius; humor; strain; quality; also, manner of speech or action; as, a rich vein of humor; a satirical vein.
The correct way to define a vein is to say that a vein is a blood vessel that carries blood back to the heart. This is a simple but vital concept as whilst the pulmonary veins carry blood back to the heart, the blood they carry is oxygenated blood brought back to the heart from the lungs following gas exchange (carbon dioxide exchanged for oxygen).