In The Blood

BEDA 2018, Miscellaneous

Day 8 of BEDA!

We’re already one week down, I hope you’re enjoying the blogs so far. Today I’m going to give you the quick and dirty facts on blood. Why we need it and what do different blood types actually mean! Either way here are 6 common questions about blood answered!

What is blood?

The dictionary defines blood as:

the fluid that circulates in the principal vascular system ofhuman beings and other vertebrates, in humansconsisting of plasma in which the red blood cells, whiteblood cells, and platelets are suspended

What are the main functions of blood?

Blood is like the transport system of your body that is pushed round by the heart. It distributes nutrients, oxygen, hormones, antibodies and cells specialized in defense to tissues and collects waste such as nitrogenous wastes and carbon dioxide from them.

What is blood made from?

Blood is made of a liquid and a cellular portion. The fluid part is called plasma and contains several substances, including proteins, lipids, carbohydrates and mineral salts. The cellular components of blood are also known as blood corpuscles and they include erythrocytes (red blood cells), leukocytes and platelets.

What are the different blood types?

There are four main blood groups, A, B, O and AB.

  • blood group A – has A antigens on the red blood cells with anti-B antibodies in the plasma
  • blood group B  – has B antigens with anti-A antibodies in the plasma
  • blood group O  – has no antigens, but both anti-A and anti-B antibodies in the plasma
  • blood group AB  – has both A and B antigens, but no antibodies

Red blood cells sometimes have another antigen, a protein known as the RhD antigen. If this is present, your blood group is RhD positive. If it’s absent, your blood group is RhD negative.

Therefore you can be one of eight blood groups, A+, A-, B+, B-, O+ (like me!), O-, AB+ and AB-. Some blood groups are rarer than others (see below photo) and some blood groups are more prevalent in different races.

Photo credit: Quora

Why is it important that blood types match when giving blood transfusions?

Because of the different antigen present on different blood types it’s important that the donor blood has the same antigens as the recipient. If a donor has red blood cells with antigens not present in the red blood cells of the recipient (a lack of transfusion compatibility), the immune system of the recipient recognizes these molecules as actual antigens (or rather, foreign substances) and triggers a defense response, producing specific antibodies against those antigens. The transfused red blood cells are then destroyed by these antibodies and the recipient may even die.

Image result for blood types

Photo credit:

Are there blood diseases?

Unfortunately yes, there are many different kinds of blood diseases. Some blood diseases include Leukemia and lymphoma which are blood cancers.

(Science Photo Library) (Credit: Science Photo Library)

Photos of blood types – Photo credit: Zimmer

On a side note most people can go and give blood! I do as often as I can. In the U.K. you can give a blood donation (that doesn’t really hurt at all apart from a couple of sharp scratches) and get many free snacks (biscuits and juice galore!), they will then tell you where your blood has been used. 1 blood donation can save up to three lives! It’s an amazing thing to be able to help total strangers. If you are interested you can sign up here – 

ThatBiologist Everywhere!





If you like this you might like these blogs too!

  1. 6 in 60 – The Blood
  2. 7 Weird Things That Can Kill You
  3. 6 in 60: Number 26 – Heart

6 in 60: Number 47 – Blood


I thought for the next 3 blogs we would look back into the human body and look at blood, skeletons and muscle. Enjoy!

  1. Blood can be defined as the fluid that circulates in the principal vascular system of low red blood cell counthuman beings and other vertebrates, in humans consisting of plasma in which the red blood cells, white blood cells, and platelets are suspended.
  2. Blood pH is held from 7.35 to 7.45 making it slightly basic.
  3. There are four main blood groups (types of blood): A, B, AB and O. Your blood group is determined by the genes you inherit from your parents. Each group can be either RhD positive or RhD negative, which means your blood group can be one of the eight types
  4. Scientists have estimated the volume of blood in the human body to be eight percent of body weight.
  5. The body contains approximately 0.2 milligrams of gold that is most diffused with our blood. However, you would need to bleed 40,000 people dry just to collect enough blood to make an 8-gram souvenir.
  6. Coconut water can be used in emergencies as a replacement for blood plasma. This is because coconut water possesses identical properties to that of human plasma, and since it can be safely injected directly into the bloodstream.


I got the first from just a standard dictionary (yes I still use them!). The second fact is from medicnet but you can find this all over the internet. The third fact comes form this nhs page. The last three facts come from medical daily which can be found here.

Want more 6 in 60 – click here!

ThatBiologist Everywhere!



Could Vampires Be Real?


One of the most popular halloween characters are the vampires. Recently on popular media we’ve gone crazy for the blood sucking fantastical creatures. In this blog I wanted to look at the biology behind them and maybe look at whether they could be real.

The most famous vampire of them all has to be dracula. The story of dracula was actually built from the legend of vlad the impaler. Coming from the House of Drăculești he was a leader in Romania and Bulgaria. He used impaling upon his enemies which was why he ended up with his name. There were rumours that he then drank the blood of his enemies and hense the story of Dracula the vampire began.

The general ruling across mythology is that vampires are humans that died and were brought back to life by another vampire and require blood to drink. Excluding the other theories of whether they sparkle in the sunlight or burst into flames. In real life there are some creatures that drink blood.

250px-DesmodusVampire bats are a good one to start off with. Desmodus rotundus or the common vampire bat alongside two other species of vampire bat can be found in central and south america. They use infra-red radiation to locate blood hotspots on their prey. They have short muzzels and sharp teeth so they can latch on and drink the blood. Anticoagulants are released so the wound does not heal too quickly and then the blood is digested to obtain the nutrients.  An interesting fact about vampire bats is that they often urinate within two minutes of feeding. They live as a colony and if one bat was unable to find food that evening it may ask for a donation from another bat.

So what would happen if a human drank blood? Well in actual fact if you did as the stories say and drained and drank all of the blood contained within a human, about an average of 5 litres by the way, you would die alongside that person. You would die from a number of different causes mainly from lead poisoning or haemochromatosis. This causes major damage to the liver and nervous systems. This could also happen by drinking blood often over time.

To conclude, could vampires be real? Well vampire characteristics are apparent in plenty of different animals, the bats but also leeches. As for a human vampire my answer is no. The human anatomy could not cope with blood in the system over a prolonged period of time. With all this being said there is no reason why you can’t dress up in a cape and pop on some fake fangs. You could even chuck on some glitter when you walk into the sun.

Hope you enjoyed this blog. Happy Halloween! 

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