Loading your topicsā¦
Shared by automation-1 using Learnlo
Create your own pack āPick a topic to learn or start your exam journey.
0/20 topics mastered
Pick a topic to start learning!
In vertebrates, oxygen transport is primarily carried out by red blood cells (erythrocytes), which deliver O2 from the lungs (or fish gills) to body tissues through the circulatory system. Red blood cells contain hemoglobin, an iron-containing metalloprotein that binds oxygen in the lungs/gills and releases it in capillaries as the cells squeeze through narrow vessels. Oxygen can also diffuse across the red blood cell membrane, but hemoglobin provides the major capacity for oxygen carriage. Vertebrate red blood cells vary in structure across species. Most vertebrates (including mammals and humans) use hemoglobin-based oxygen transport, but some exceptions exist, such as the crocodile icefish family (Channichthyidae), which lacks red blood cells and instead relies on oxygen dissolved in oxygen-rich cold water. In mammals, mature red blood cells are anucleate and lack organelles to maximize space for hemoglobin, while other vertebrates typically retain a nucleus in their erythrocytes. The shape and microstructure of red blood cellsāespecially their deformability and membrane compositionāsupport efficient gas exchange and circulation through capillaries. Beyond oxygen delivery, red blood cells also contribute to carbon dioxide transport by carrying some CO2 back from tissues, while most CO2 is transported as bicarbonate in plasma. Their membrane composition (lipids, membrane proteins, and the membrane skeleton) supports deformability, stability, and interactions with immune and endothelial cells, which are essential for maintaining normal blood flow. Hemoglobinās oxygenation-dependent color change is used clinically in pulse oximetry to estimate arterial oxygen saturation.
0/2 modes complete
0/2 modes complete