A variety of different systems and pumps (hearts) have developed, but they all have a few things in common.
These include something to carry oxygen around their bodies, a fluid of some sort, and some “plumbing” – in humans (and a number of other species) the fluid is called blood and the plumbing is our arteries, veins and capillaries. Depending on the organism and where it has adapted to live, its oxygen carrier can come in different forms, often giving its “blood” different colours.
The colour comes from a chemical known as haem, which contains iron.
It’s the iron that is the crucial ingredient for carrying oxygen.
Red blood cell, also called erythrocyte, cellular component of blood, millions of which in the circulation of vertebrates give the blood its characteristic colour and carry oxygen from the lungs to the tissues.
The mature human red blood cell is small, round, and biconcave; it appears dumbbell-shaped in profile.
The first is haem, a flat ring structure that holds an iron atom at its centre.
Haem is held closely by proteins known as globin, and this combination forms haemoglobin, which is itself packaged up in red blood cells to be transported around the body.
Australian governments fund the Australian Red Cross Blood Service for the provision of blood, blood products and services to the Australian community.
This week we’re running a series in collaboration with the Australian Red Cross Blood Service looking at blood: what it actually does, why we need it, and what happens when something goes wrong with the fluid that gives us life. Just as a village can’t grow into a city without some form of transport (road, rail or river) that provides necessary interconnections for it to flourish, living things are limited in the size they can reach unless they have some form of circulatory system to transport nutrients and remove waste.