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.
The noun VENA CAVA has 1 sense: 1  1. either of two large veins that return oxygen-depleted blood to the right atrium of the heart. 2  Meaning: 3  Either of two large veins that return oxygen-depleted blood to the right atrium of the heart. 4  Classified under: 5  Nouns denoting body parts. 6  Hypernyms (vena cava is a kind of...): vein; vena; venous blood vessel (a blood vessel that carries blood from the capillaries toward the heart) Hyponyms (each of the following is a kind of vena cava): inferior vena cava; postcava (receives blood from lower limbs and abdominal organs and empties into the posterior part of the right atrium of the heart; formed from the union of the two iliac veins)