Preface

Today, information in medical science increases rapidly and with the communication age, accessing information is quite easy. However, with this increasing knowledge, information complexity has emerged. Thus, despite all this increasing knowledge, the interest in and need for basic books has not diminished.

Red blood cells constitute approximately 40% of the total amount of blood and 99% of shaped elements of blood. Their major function is oxygen transportation and this makes erythrocytes "the basis of life." However, as readers will see in this book, erythrocytes have a lot of different, important functions in our body. We have learned a great deal so far, but there is still more to learn about erythrocytes. Erythrocyte evolution continues and this book plans to collect current information related to erythrocytes.

I would like to thank all the authors and IntechOpen in the hope that this book will be a stepping stone for scientists who are rapidly advancing their science journey

**II**

**Section 2**

Vesicles

Future Perspectives **119**

**Chapter 8 121**

**Chapter 9 137**

**Chapter 10 151**

The Biology and Therapeutic Applications of Red Blood Cell Extracellular

Application of Red Cell Membrane in Nanobiotechnology

The Influence of the Golden Ratio on the Erythrocyte

*by Insu Kim, Gyudo Lee and Dae Sung Yoon*

*by Marcy C. Purnell and Risa D. Ramsey*

*by Daniel Xin Zhang, Theodoros Kiomourtzis, Chun Kuen Lam and Minh T.N. Le*

**Dr. Anil Tombak, MD** Associate Professor Department of Internal Medicine—Hematology, Mersin University Medical Faculty, Mersin, Turkey

**1**

Section 1

Erythrocytes: Physiology

and Pathophysiology

Section 1

Erythrocytes: Physiology and Pathophysiology

**3**

the erythrocytes and to the blood.

**Chapter 1**

*Anil Tombak*

**1. Introduction**

Introductory Chapter:

ing to age, gender, and height of place [1].

indicate deviations in the production of these erythrocytes.

Erythrocytes - Basis of Life

Erythrocytes (**Figure 1**) constitute approximately 40% of the total amount of the blood and 99% of shaped elements in the blood. They are biconcave diskshaped cells with an average diameter of 6.2–8.2 μm, a thickness at the thickest point of 2–2.5 μm, and a minimum thickness in the center of 0.8–1 μm. These dimensions make the red blood cells smaller than most other human cells. One millimeter cube of blood contains 5,100,000–5,800,000 erythrocytes in men and 4,300,000–5,200,000 red blood cells in women. These numbers may vary accord-

The red blood cells are produced in the vitellus sac during the first few weeks of the fetus, in the spleen, lymph nodes, and liver in the second trimester, and in the bone marrow in the last month before and after birth. Red blood cells are produced in the bone marrow of all bones up to 5 years of age; after the age of 20, they are produced in the bone marrow of vertebrae, sternum, ribs, and iliac bone. All circulating cells are formed by dividing hemopoietic stem cells in the bone marrow.

The production of red blood cells is controlled by erythropoietin hormone produced by the kidneys (90%) and by the liver (10%). The production of red blood cells begins as immature cells in the bone marrow and they mature approximately 7 days later and are released into the blood stream. Initially, the red blood cells are added to the circulation in the form of reticulocytes and reticulocytes become erythrocytes in circulation within 2 days. Reticulocytes typically contain remnants of organelles. Reticulocytes should comprise approximately 1–2% of the erythrocyte count. When oxygen decreases in tissues, the erythropoietin hormone level rises, and red blood cell production is stimulated; however, after 5 days, the new red blood cells appear in the circulation. Abnormally low or high levels of reticulocytes

Red blood cells lack endoplasmic reticula and do not synthesize proteins. They lack mitochondria as well and rely on anaerobic respiration. However, erythrocytes contain a special protein called hemoglobin, which carries oxygen from the lungs to other parts of the body and carries carbon dioxide into the lungs. No mitochondria mean that erythrocytes do not utilize any of the oxygen they are transporting, so they can deliver it all to the tissues. Approximately 90% of red blood cells are hemoglobin. Erythrocytes allow regulation of acid-base balance through hemoglobin. The hemoglobin level in whole blood is 16 g/dl in men and 14 g/dl in women. In a red blood cell, there is an average of 270–300 million molecules of hemoglobin. Each hemoglobin molecule contains four globin groups, each of which can bind a molecule of oxygen. Total iron in the body is 4–5 g, and 65% of this is found in hemoglobin. Hemoglobin molecule gives the red color to

## **Chapter 1**
