The incredible qualities of our blood

June 14, 2016

Article by Global Pre-Meds
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Today is World Blood Donor Day, and in celebration of the millions of life-saving transfusions that happen across the globe, we’ve made this guide to one of the most interesting aspects of the human body.

Five Quick Facts

1. Your blood makes up for 7% of your weight

2. You make 17 million red blood cells per second

3. HP Printer Ink is more expensive than the same volume of donated blood

4. A red blood cell makes a complete circuit of your body in around 30 seconds

5. In 24 hours your blood travels 12,000 miles

Types of Blood

Many of us will know that there are several different blood types even if we don’t know our own. There are four types of blood: A, B, O or AB, and each type can be either positive or negative for the Rh factor (making 8 primary blood types in all). Blood type O- is usually safe for most people, and is often used in emergencies where a patient’s blood type is not immediately known. Blood type O+ is needed most frequently.

What makes blood so special?

Your blood is responsible for so much of your day-to-day functioning. When you are exercising, your blood pumps faster to deliver oxygen to your muscles. When you have eaten, your blood travels to your internal organs to help power your small and large intestines. When you are cold, your veins constrict to reduce heat loss. Your blood delivers nutrients, oxygen and even medication to each and every corner of your body. And your heart never stops pumping for as long as you live!

Using blood donations in medicine

Although some (unsuccessful) procedures occurred before this time, 19th Century obstetrician James Blundell is attributed with properly introducing blood transfusions into everyday medicine.

Nowadays, all donated blood is tested for infectious diseases after collection (even after you complete a medical survey). The blood is also spun in a centrifuge to separate out the platelets, plasma and red cells (the parts that are transfused).  

Medical professionals know only too well the mind-blowing qualities of human blood, as well as the problems that blood loss or blood diseases can cause. In the field of oncology, infusion therapy (or IV) nurses are trained to treat cancer patients by administering chemotherapy drugs into their bloodstream. In the field of cytology, blood samples are used to identify an enormous range of conditions and in emergency medicine, a blood transfusion can save a patient’s life – 10% of people who are admitted to hospital will need one.

Over half the world’s blood donations take place in high-income countries, but only 18% of the world’s population live there. Unfortunately, there is often a shortage of safe blood in areas where it is desperately needed.

What does the future hold?

Modern advances in medicine mean that health professionals and scientists are regularly discovering ways we can use blood to treat a range of different conditions.

Scientists at Stanford University recently discovered that injecting young blood into older humans could potentially slow down or even reverse the ageing process! While there are always ethical decisions to be made when such theories come to light, research like this shows that when it comes to this magical substance, the sky may well be our limit.



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Gap Medics provides year-round hospital work experience for people aged 16 and over. Our shadowing placements offer a unique insight into the work of doctors, nurses, midwives, and dentists – helping students to focus their career aspirations before embarking upon medical training.