My son is half way through his GCSE exams. One night this week I was helping him with biology. I found it interesting to look back through a revision book and be reminded of all the things I learned that started me off in medicine many years ago.
One of the things that really struck me is how amazing our bodies are.
We started reading about blood cells. We have red blood cells that are specially shaped so they can squeeze through tiny blood vessels.
They are also made without a nucleus so there is more space for haemoglobin which carries oxygen to our body organs and muscles.
We produce white cells, which have the ability to recognise invaders in the body, and then produce antibodies. These antibodies are a perfect fit to block the invader cells from causing disease on our bodies.
Then we have platelets which enable our blood to clot, so when we get a scratch or cut we can heal ourselves.
We looked at the structure of our eye – how the lens adapts to enable light to land on our retina from near and far objects, then the cells of the retina are specialised to interpret the light and a message is sent via the optic nerve to the brain.
I find it amazing how we can see and hear and smell –things we take for granted in everyday life.
Then we learned about how cells divide, how the DNA is packed into chromosomes, which are able to divide and copy themselves, so that each new cell has the same DNA code.
The DNA code is specialised and unique for each person, two metres of “computer coding” in each cell nucleus.
Some cells specialise into muscle cells, or heart cells, or neurones for the nervous system.
And certain cells divide differently to produce egg and sperm, which only have 23 chromosomes, ready for fertilisation.
I was reminded afresh how phenomenal this all is.
To think that a person develops from an egg and sperm that are invisible to the naked eye.
To think that our bodies are able to make new cells appropriately for each organ and tissue, for our whole lives.
To think that we are made with enzymes and hormones, defence systems and nerve feedback mechanisms, a skeletal and muscle system for movement.
To think that no two people in the whole of human history are the same.
I think it’s amazing!
* Dr Mary Wren, Sheffield GP