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Difference Between Red Blood Cells and White Blood Cells

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What Is the Difference Between RBC and WBC in Structure and Function

Both red blood cells and white blood cells play an essential role in the human body. Red blood cells or RBC carry oxygen to the tissues in different parts of the body. White blood cells or WBC strengthen the defense mechanism of the body by generating antibodies. The primary difference between RBC and WBC lies in their functionality. While RBCs act as carriers, WBC act as creators. The experts at Vedantu have summarized the difference between red blood cells and white blood cells in a comprehensive manner.


Red Blood Cells (RBC)

As the name suggests, RBC is red because of the presence of hemoglobin which is an iron-rich protein and binds with oxygen to get the red color. RBC gives a red color to the blood because of its presence in the blood in a large number. Also known as Erythrocytes, red blood cells are round, small, and bi-concaved in shape but due to their flexibility, they appear bell-shaped when passing through small vessels. They carry oxygen to the tissue in the body. To maintain a healthy RBC count in the body, it is essential to take an iron and vitamin-rich diet. A low RBC count causes anemia and its common symptoms are irregular heartbeat, pale skin, feeling cold, fatigue, and joint pain.


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The primary function of Red Blood Cells is to carry oxygen from the lungs to the tissue in different parts of the body, using the blood circulation system. They also carry carbon dioxide back to the lungs from where they are excreted out of the body. Since the RBC has a bi-concave shape it helps in the exchange of oxygen at a constant rate and over a large surface area.


White Blood Cells (WBC)

White Blood Cells are colorless due to the absence of hemoglobin in them. Also known as Leukocytes, white blood cells protect the body from any infections by producing antibodies that build up the defense system of the body against germs and infections. One of the other important factors that help us to differentiate between RBC and WBC is the circulation system used by these cells. WBC uses cardiovascular circulation and is also present in the lymphatic system. Red blood cells use only the cardiovascular circulatory system. Invading bacteria, viruses, and germs are attacked by these cells, which aid in the fight against infection.


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Although white blood cells begin in the bone marrow, they circulate throughout the body. There are five different types of white blood cells:

  • Neutrophils

  • Lymphocytes

  • Eosinophils

  • Monocytes

  • Basophils


The primary function of white blood cells is to produce antibodies in the body and to strengthen immunity of the body. A good defense mechanism protects the body from any germ attacks or infections. WBC protects the body by digesting the foreign material and cancer cells present in the body by producing antibodies.


Let’s look at the difference between red blood cells and white blood cells in detail.


Difference Between Red Blood Cells and White Blood Cells

Criteria

RBC

WBC

Scientific name 

RBC is scientifically called Erythrocytes.

WBC is called Leukocytes.

Appearance

RBCs are anucleated, bi-concave, and disc-shaped.

WBC are nucleated and irregular in shape.

Size

The size of RBC is roughly 6-8 microns.

The size of WBC is 15 microns.

Production location

RBC is produced in the red bone marrow.

WBC is produced in the spleen, lymph nodes, etc.

Production number

Almost 2 million RBC are produced in the body per second.

WBC are produced in a comparatively lower number than the RBC.

Formation process 

The process of RBC formation is called Erythropoiesis.

The process of WBC formation in the body is called leucopoiesis.

Motility

Red Blood Cells are non-motile.

White blood cells are motile

Percentage in blood

RBC accounts for 36%-50% of the blood in the body. This percentage, however, differs according to the height, weight, and age of the person.

In comparison, WBC constitutes a meager 1% of the blood.

Types

Red blood cells are only of one type.

White blood cells are of multiple types. T-lymphocytes, B-lymphocytes (plasma cells), monocytes (macrophages), neutrophils, eosinophils, and basophils are some of the types of WBC.

Life span

RBC can survive up to 120 days in the body.

WBC can survive anywhere between several days to even several years in the body.

Constitution

RBC is made up of only hemoglobin.

WBC is made up of antibodies with MHC antigen cell markers.

Colour 

The presence of hemoglobin lends a red color to the RBC. It is the reason they are called red blood cells.

The absence of hemoglobin makes WBC colorless.


Function

The primary function of the RBC is to carry oxygen to the various parts of the body. As a secondary function, they also carry waste materials and carbon dioxide to the lungs.

The primary function of WBC is to produce antibodies to strengthen the defense mechanism of the body. These antibodies protect the body from any attack by germs and provide immunity against infections. Some of them are also phagocytic.

Circulation

The circulation system used is the cardiovascular system that is related to the blood vessels and the heart.

The circulation systems used are cardiovascular as well as lymphatic. 

Low count effect

A low RBC count in the body can lead to anemia which can affect the body’s ability to carry and supply oxygen to the tissues.

A low WBC count can lead to leukopenia that can hamper the immune system of the body.

High count effect

A high RBC count is produced in the body during exercise or at high altitudes.

A high WBC count is an indication of infection present in the body or of a lower response rate of the bone marrow. Such a condition is called Leukocytosis.

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FAQs on Difference Between Red Blood Cells and White Blood Cells

1. What is the difference between RBC and WBC?

The main difference between RBC (Red Blood Cells) and WBC (White Blood Cells) is that RBCs transport oxygen, while WBCs protect the body against infections.

  • RBCs contain hemoglobin and carry oxygen from lungs to tissues.
  • WBCs are part of the immune system and fight bacteria, viruses, and other pathogens.
  • RBCs lack a nucleus in humans, whereas WBCs have a distinct nucleus.
  • RBCs are more numerous than WBCs in blood.
This functional and structural difference is key in understanding the difference between RBC and WBC.

2. What is the function of red blood cells (RBCs)?

The primary function of red blood cells (RBCs) is to transport oxygen and carbon dioxide in the blood.

  • They carry oxygen from the lungs to body tissues using hemoglobin.
  • They transport carbon dioxide from tissues back to the lungs.
  • They help maintain the body’s acid-base balance.
RBCs are essential for cellular respiration and energy production in the body.

3. What is the function of white blood cells (WBCs)?

The main function of white blood cells (WBCs) is to defend the body against infections and foreign invaders.

  • They identify and destroy pathogens like bacteria and viruses.
  • Some WBCs produce antibodies.
  • Others perform phagocytosis by engulfing harmful microorganisms.
WBCs play a crucial role in the body’s immune response and disease prevention.

4. Do RBCs and WBCs have a nucleus?

In humans, RBCs do not have a nucleus, while WBCs contain a clearly defined nucleus.

  • Mature RBCs lose their nucleus to make more space for hemoglobin.
  • WBCs retain their nucleus to control immune functions and cell division.
This structural difference helps distinguish RBCs from WBCs under a microscope.

5. Which is more numerous in blood, RBCs or WBCs?

Red blood cells (RBCs) are far more numerous in blood than white blood cells (WBCs).

  • Normal RBC count: about 4.5–6 million cells per microliter of blood.
  • Normal WBC count: about 4,000–11,000 cells per microliter.
This large difference reflects the major role of RBCs in continuous oxygen transport.

6. What are the types of white blood cells?

There are five main types of white blood cells (WBCs), each with a specific immune function.

  • Neutrophils – fight bacterial infections.
  • Lymphocytes – include B cells and T cells for adaptive immunity.
  • Monocytes – differentiate into macrophages.
  • Eosinophils – combat parasitic infections.
  • Basophils – involved in allergic responses.
These types collectively protect the body from various pathogens.

7. What is the structure of RBC compared to WBC?

The structure of RBCs is a biconcave disc without a nucleus, while WBCs are irregular in shape and contain a nucleus.

  • RBCs have a biconcave shape that increases surface area for oxygen exchange.
  • WBCs have a larger size and visible nucleus.
  • RBCs lack most organelles, while WBCs contain organelles for immune activity.
These structural differences relate directly to their distinct functions in blood.

8. Where are RBCs and WBCs produced in the body?

Both RBCs and WBCs are produced in the red bone marrow through a process called hematopoiesis.

  • RBC formation is called erythropoiesis.
  • WBC formation is called leukopoiesis.
  • Some WBCs, like lymphocytes, mature in lymphoid organs such as the thymus and lymph nodes.
This production ensures a constant supply of blood cells for transport and immunity.

9. What happens if RBC count or WBC count is abnormal?

An abnormal RBC or WBC count can indicate disease or infection.

  • Low RBC count may cause anemia, leading to fatigue and weakness.
  • High RBC count may indicate polycythemia.
  • High WBC count, called leukocytosis, often signals infection.
  • Low WBC count, called leukopenia, increases infection risk.
Blood tests help diagnose these abnormalities.

10. How long do RBCs and WBCs live?

The average lifespan of RBCs is about 120 days, while WBCs may live from a few days to several years depending on the type.

  • RBCs circulate for around 120 days before being removed by the spleen.
  • Neutrophils (a type of WBC) live only a few days.
  • Some lymphocytes can live for months or years as memory cells.
The lifespan difference reflects their different roles in oxygen transport and immune defense.