Red Blood Cells

Red blood cells, also known as erythrocytes, are the most common type of blood cell in the human body. Their primary function is to transport oxygen from the lungs to the rest of the body, and to transport carbon dioxide from the body to the lungs for exhalation.

Structure of Red Blood Cells

Red blood cells are small, biconcave discs that have a diameter of about 6-8 micrometers. They are filled with a red pigment called hemoglobin, which is responsible for the cells' red color and their ability to carry oxygen. Hemoglobin molecules are composed of four heme groups, each of which can bind to one molecule of oxygen.

Formation of Red Blood Cells

Red blood cells are produced in the bone marrow through a process called erythropoiesis. This process is regulated by the hormone erythropoietin, which is produced by the kidneys in response to low oxygen levels in the blood. Erythropoietin stimulates the bone marrow to increase the production of red blood cells.

Function of Red Blood Cells

The main function of red blood cells is to transport oxygen to the body's tissues and organs. They do this by binding to oxygen in the lungs and releasing it in the capillaries throughout the body. Additionally, red blood cells also transport a small amount of carbon dioxide from the body's tissues back to the lungs for exhalation.

Study Guide

1. What is the primary function of red blood cells?
2. Describe the structure of red blood cells.
3. How are red blood cells produced?
4. What hormone regulates the production of red blood cells?
5. Explain the function of hemoglobin in red blood cells.

Understanding the structure, function, and formation of red blood cells is essential for comprehending the role they play in the human body's oxygen transport system.