Living As... A Red Blood Cell
If there's a type of cell that epitomises the 'live fast, die young' lifestyle, it's the red blood cell. But what is it really like to go rushing around our vital organs all day long? Hannah Isom dives in and takes a look.
Red blood cells are undoubtedly the grafters of the cell world. Their sole mission in life is to rush around our blood vessels, making sure all of our organs and muscles are serviced with oxygen, whilst clearing out the mess we make during respiration. It’s no wonder we need so many of them: each cubic millimetre of blood contains about 5 million of the little fellows. So what does the diary of a red blood cell (or erythrocyte if you’re going to get all Greek about it) actually look like?
Rise and shine
All cells start out life as a stem cell which, rather like a child progressing through school to college and university, must decide what to be when they grow up. The ones that choose to be red blood cells (RBCs) ditch their DNA as they mature in the bone marrow, a process which takes about 48 hours.
Mid-morningRather than stopping for elevenses, RBCs would rather do their morning exercises. They are extremely flexible, and because of their biconcave disc shape (a bit like a donut without the hole fully pierced) they can bend and twist to fit through the tiniest of capillaries. This clever shape also provides the biggest possible surface area for diffusion of gas into and out of the blood.
Lunch time
Favourite foods for red blood cells include spinach, broccoli and red meat, or anything with a high iron content. They use the iron in these foods to make haemoglobin – the molecule which binds oxygen and carbon dioxide. Each cell contains 270 million molecules of haemoglobin; these are what give blood that delightful red hue. If we don’t eat enough iron, we can’t make enough haemoglobin, which can lead to anaemia.
Afternoon
After all that eating, it’s time for the RBCs to get down to some serious work. Their day job involves picking up deliveries of oxygen from the lungs, navigating the maze of arteries and capillaries to reach their destination, our body tissues, and then unloading the goods. They even pick up the carbon dioxide that is produced as a by-product of chemical reactions and ferry it via our veins back to the lungs to be exhaled.
Goodnight
Red blood cells certainly adhere to the ‘live fast, die young’ philosophy. After about 120 days, they are destroyed in the liver, the spleen or in the bone marrow itself. But worry not! There are 2 million new little O2 couriers being made every second, ready to take up the mantle of keeping us alive.
Find out more about Hannah's days on her homepage or stick with the links below:
- Day in the Life - Labradorite
- How It Works - Wi-tricity: cordless power
- What it is - A is for Amino Acid
- What is ain't - Science solves tiddlywinks
Image: W
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