Rbc Function and Metabolism: Learning Objectives
Medical Importance
The primary function of the erythrocyte is to deliver oxygen. Hemoglobin structure and function, red blood cell metabolism, and red blood cell membrane structure are essential in maintaining optimal oxygen delivery. This requires energy and an active redox defense system to prevent excessive oxidation. Understanding the life and death of the red blood cell underpins the pathophysiologic processes of hemolysis.Objectives
- Describe the pathway and rate-limiting steps by which heme is synthesized.
- List the normal hemoglobins found in fetal and adult blood.
- Draw a normal hemoglobin oxygen dissociation curve, identify P50 on the curve, and show the direction of shift of the curve elicited by increases or decreases of pH, 2,3-DPG concentration, C02 concentration, HbF, increased temperature, and HbS.
- Apply knowledge of the RBC membrane and metabolism and to explain how defects in these structures and processes induce specific hematological disease states.
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Recognize the Embden-Meyerhof pathway and describe:
- How the pathway helps regulate the reduction of methemoglobin back to hemoglobin.
- How the pathway relates to 2,3-DPG production.
- Describe the function of the hexose monophosphate shunt and how this helps protect red cells from oxidant stress.
- Identify the site of red blood cell destruction and the process by which this is accomplished.