Red Blood Cells Hemoglobin Flashcards
How many erythrocytes are in the body
4.5-6.3 million cells/1 microliter; 1/3 of all cells in the body
Shape of erythrocytes and their internal structures
biconcave disc; cytoskeleton
What internal structures do erythrocytes not have
nucleus, ribosomes, mitochondria
Structure of hemoglobin
4 globular polypeptide chains, each chain has heme
Function of hemoglobin
transports oxygen and carbon dioxide; red pigment of blood
What is hypoxemia
low oxygen in the body
What is erythropoiesis
process of erythrocyte production
How long do erythrocytes last
120 days
Where does erythropoiesis occur
red bone marrow
What cells give rise to erythrocytes
erythroblasts
What hormone triggers erythropoiesis?
erythropoietin (EPO)
What organ secretes erythropoietin
kidneys and liver
Hemoglobin recycling process
- macrophages engulf old erythrocytes and removed hemoglobin
- iron is removed from the hemoglobin
- rest is converted to biliverdin, then bilirubin
- binds to albumin
- passes through the liver and excretes through the bile
Iron recycling process
- iron removed from heme leaving biliverdin
- irons is moved to transport proteins transferrin to be recycled in red bone marrow
- excess iron is moved to storage proteins ferritin and hemosiderin
Biliverdin breakdown process
- biliverdin (green) is converted to bilirubin (yellow)
What is jaundice caused by
bilirubin build up
How does hemoglobin know when to hold or release oxygen?
