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.
Definition of vein for English Language Learners. : 1  any one of the tubes that carry blood from parts of the body back to the heart. : 2  any one of the thin lines that can be seen on the surface of a leaf or on the wing of an insect. : 3  a long, narrow opening in rock filled with gold, silver, etc.