Life span of ‘RBC’ is ______.
120 days
Understanding the Lifespan of Red Blood Cells (RBCs)
Red Blood Cells, commonly known as RBCs or erythrocytes, are a vital component of blood. Their primary function is to transport oxygen from the lungs to the body's tissues and carry carbon dioxide from the tissues back to the lungs. These cells have a specific life cycle, after which they are removed from circulation and broken down.
What Determines RBC Lifespan?
Unlike many other cells in the body, mature Red Blood Cells in mammals are unique because they lack a nucleus and other organelles like mitochondria. The absence of a nucleus means that RBCs cannot synthesize new proteins or repair themselves effectively. This limitation ultimately determines their lifespan.
Typical Lifespan of Human Red Blood Cells
The average lifespan of a Red Blood Cell (RBC) in a healthy human adult is relatively consistent. After being produced in the bone marrow, they circulate in the bloodstream performing their function for a specific period.
The typical lifespan of a Red Blood Cell (RBC) is approximately:
- 120 days
After this period, the aging RBCs become less flexible and are eventually recognized and removed from the circulation, primarily in the spleen and liver, through a process called phagocytosis.
| Blood Cell Type | Approximate Lifespan |
|---|---|
| Red Blood Cell (RBC) | 120 days |
| Platelets | 8-10 days |
| White Blood Cells (WBCs) | Varies greatly (hours to years depending on type) |
Understanding the lifespan of RBCs is important in various medical contexts, such as assessing chronic blood loss or evaluating the effectiveness of certain treatments for blood disorders.
How are Old RBCs Removed?
Aging Red Blood Cells undergo changes in their cell membrane that make them more rigid. As they pass through the narrow capillaries of organs like the spleen and liver, these less flexible cells are detected and engulfed by specialized cells called macrophages. The components of the broken-down RBCs, such as iron from haemoglobin, are often recycled.
Revision Table: Key Facts about RBC Lifespan
| Concept | Detail |
|---|---|
| Cell Name | Red Blood Cell (RBC) / Erythrocyte |
| Main Function | Oxygen transport (via Haemoglobin) |
| Lifespan | Approximately 120 days |
| Reason for limited lifespan | Lacks nucleus and organelles; cannot repair itself |
| Site of Production | Bone Marrow (Erythropoiesis) |
| Site of Destruction | Spleen, Liver (Reticuloendothelial System) |
Additional Information: Beyond RBC Lifespan
The study of Red Blood Cells involves several related concepts:
- Erythropoiesis: This is the process of RBC production, which occurs primarily in the red bone marrow. It is stimulated by the hormone erythropoietin, released by the kidneys, typically in response to low oxygen levels.
- Haemoglobin: The protein inside RBCs responsible for binding and transporting oxygen. Each RBC contains millions of haemoglobin molecules.
- Anemia: A condition characterized by a lower-than-normal number of RBCs or less haemoglobin, leading to reduced oxygen transport capacity. It can be caused by various factors, including decreased RBC production, increased RBC destruction (hemolysis), or blood loss.
- Blood Transfusion: The process of receiving blood or blood components (like packed RBCs) into one's circulation. Understanding RBC lifespan is crucial for blood storage and transfusion practices.
The finite lifespan of Red Blood Cells necessitates continuous production to maintain a healthy blood count and ensure adequate oxygen delivery throughout the body.
Important Questions from Non-Verbal Reasoning
Choose the alternative which most closely resembles the water image of the given figures.
Select a figure from the given four alternatives, which when placed in the blank space of the problem figure would complete the pattern.
Choose the alternative which most closely resembles the mirror image of the given combination: MARKER
Among the four answer figures, which one can be formed from the cut-out pieces given below?
Find the alternative which contains figure (A) as its part.
