punavererakkudes

Punavererakkudes, also known as erythrocytes or red blood cells, are the most common type of blood cell in vertebrates. They are responsible for transporting oxygen from the lungs to the body's tissues and carrying carbon dioxide from the tissues back to the lungs. Red blood cells are biconcave discs, meaning they are flattened discs that are indented on both sides. This shape increases their surface area, allowing for more efficient gas exchange.

In mammals, mature red blood cells lack a nucleus and most organelles, which maximizes the space available for hemoglobin, the protein that binds to oxygen. Hemoglobin gives red blood cells their characteristic red color. Red blood cells are produced in the bone marrow through a process called erythropoiesis. Their lifespan is typically around 120 days, after which they are removed from circulation by macrophages in the spleen and liver.

The number of red blood cells in the blood is a critical indicator of health. A low red blood cell count, known as anemia, can result from various causes, including nutritional deficiencies, blood loss, or chronic diseases, and can lead to fatigue and weakness. Conversely, a high red blood cell count, or polycythemia, can increase blood viscosity and pose health risks. The production and regulation of red blood cells are influenced by hormones, particularly erythropoietin, which is produced by the kidneys in response to low oxygen levels.