What is the primary function of red blood cells?

NORCET 1 - 2020

Applied Physiology

Easy

Appeared in: NORCET 1 - 2020

Explanation

The principal function of red blood cells (erythrocytes) is the transport of oxygen from the lungs to the body's tissues.
This is possible because RBCs are filled with hemoglobin, an iron-containing protein that readily and reversibly binds to oxygen.
The biconcave disc shape of RBCs provides a large surface area, which facilitates the efficient exchange of oxygen and carbon dioxide.
In addition to oxygen transport, RBCs also assist in carrying carbon dioxide, a metabolic waste product, from the tissues back to the lungs for exhalation.

Option A: Fighting infection is the primary responsibility of white blood cells (leukocytes), which are the main cells of the body's immune system.
Option B: The process of blood clotting (hemostasis) is initiated and managed by platelets (thrombocytes) along with various clotting factors in the plasma.
Option D: Antibodies (immunoglobulins) are produced by specialized white blood cells called B-lymphocytes (specifically, plasma cells).

Visual 1: Infographic - A clear chart comparing the appearance and primary functions of red blood cells, white blood cells (neutrophils, lymphocytes, etc.), and platelets. This helps visually differentiate the roles of each component.
Visual 2: Diagram - An illustration of a red blood cell showing hemoglobin molecules inside, with some binding to oxygen molecules. This visual reinforces the mechanism of oxygen transport.

Clinical Relevance

Nursing practice connection: Knowing Functions of Blood Components helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the function of RBCs is fundamental for interpreting a Complete Blood Count (CBC). A low RBC count or low hemoglobin level indicates anemia, which signifies a reduced oxygen-carrying capacity of the blood, leading to clinical signs like fatigue, pallor, and shortness of breath.
Nurses are responsible for monitoring patients for signs and symptoms of inadequate oxygenation (hypoxia), such as cyanosis, confusion, and tachycardia. Interventions may include administering supplemental oxygen or preparing for a blood transfusion as ordered.
What if? - If a patient has chronic kidney disease, their kidneys may not produce enough erythropoietin, the hormone that stimulates RBC production. This results in a specific type of anemia (anemia of chronic disease). The nursing focus would shift to administering erythropoiesis-stimulating agents (like epoetin alfa) as prescribed and monitoring the patient's response.

How to Approach the Question

First, identify the key subject of the question: 'red blood cells'.
This is a direct recall question. Access your foundational knowledge about the main components of blood.
Recall the single most important function associated with red blood cells. The red color itself is a clue, linked to iron-rich hemoglobin.
Evaluate each option. 'Transport oxygen' is the well-known primary role of hemoglobin within RBCs.
Systematically eliminate the other options by correctly associating their functions with other blood components: 'Fight infection' -> White Blood Cells; 'Clot blood' -> Platelets; 'Produce antibodies' -> B-lymphocytes (a type of WBC).

Concept Tested & Keywords

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