punsolujen
Punsolujen, also known as erythrocytes or red blood cells, are the most common type of blood cell and the vertebrate's principal means of delivering oxygen to the body tissues—via blood flow through the circulatory system. They take up oxygen in the lungs or gills and release it into tissues throughout the body. Punsolujen contain hemoglobin, a protein that binds oxygen and gives blood its red color. They are produced in the bone marrow and have a lifespan of about 120 days, after which they are removed by the spleen. The production of punsolujen is regulated by the hormone erythropoietin. A deficiency in punsolujen or hemoglobin can lead to anemia, a condition characterized by fatigue and weakness. Conversely, an abnormally high number of punsolujen can cause polycythemia, which can lead to blood clots. The biconcave disc shape of punsolujen increases their surface area, facilitating efficient gas exchange. They lack a nucleus and most organelles when mature, which allows them to maximize their space for hemoglobin.