Red Blood Cells Flashcards
(20 cards)
What are erythrocytes?
Red blood cells, the most abundant cells in blood, responsible for oxygen and carbon dioxide transport.
What is the shape of red blood cells and its benefit?
Biconcave disc; increases surface area for gas diffusion.
Do red blood cells have a nucleus?
No, they lack a nucleus and most organelles to maximize space for hemoglobin.
What is hematocrit?
The percentage of blood volume composed of RBCs.
What is polycythemia?
Excessive RBC production; hematocrit >48% in women or >52% in men.
What is hemoglobin composed of?
Four globin protein chains and four heme groups each with an iron ion.
How many oxygen molecules can one hemoglobin carry?
Four.
What is the normal hemoglobin level?
Men: 14–18 g/dL; Women: 12–16 g/dL.
What enzyme in RBCs converts CO₂ to bicarbonate?
Carbonic anhydrase.
What gives arterial blood its bright red color?
Oxygen-bound hemoglobin.
Where are old red blood cells destroyed?
In the liver, spleen, and red bone marrow.
Which cells break down RBCs?
Macrophages.
What happens to hemoglobin during breakdown?
Split into heme and globin.
What happens to the globin component?
Broken into amino acids and reused.
What happens to the iron from heme?
Bound to transferrin and stored in the liver as ferritin or hemosiderin.
Where does transferrin transport iron?
To red bone marrow for erythropoiesis.
What happens to the non-iron portion of heme?
Converted to biliverdin → bilirubin → excreted in bile.
What pigments result from bilirubin metabolism?
Urobilin (urine) and stercobilin (feces).
What causes jaundice?
Bilirubin buildup due to liver dysfunction.
What is erythropoiesis?
The process of forming new red blood cells.
