New News Biology #18

What Does Blood Do?

Red Blood Cells = half of our blood by volume

It brings the oxygen from the lungs to the other parts of the body that need them

Adaptations of red blood cells:

They don’t have a nucleus; This enables each red blood cell to carry more oxygen with it

The red blood cells are shaped like a biconcave disk; Quite a classic shape if you ask me

Fact: Oxygen + Haemaglobin = Oxyhaemaglobin (oxygen can diffuse into cells)

White Blood Cells = <1% of blood in our body = the ‘police officers’ of our immune system

They have a nucleus, and their only purpose is to defend against invaders of our body, and conduct one of three things:

Phagocytosis; engulfs the pathogen entirely

Creates antibodies; these antibodies bind & destroy pathogens

Creates antitoxins; the antitoxins do what their name says, ‘anti’ the toxins by neutralising them

Platelets ≠ cells = ‘cell fragments’

They float around and around in our blood, and wait about to patch up skin cuts (a.k.a ‘clotting’)

As they aren’t even whole cells, it is no surprise they don’t contain a nucleus.

Plasma = makes the blood watery and enables it to flow

Carries everything, literally everything (red blood cells, white blood cells, platelets, amino acids, glucose, waste products, hormones, proteins, antibiotics, toxins, etc.)

A Regular Adult Has Roughly 5 Litres of Blood in Their System At All Times

But if a person loses too much blood (e.g. in an accident), then there isn’t enough blood to take the oxygen to the tissues, which is bad for their body

So the only way to keep them alive is to replace the blood with either of the following:

Artificial blood (salt water); it adds volume to our system, however, it can only replace one-third of our blood, and doesn’t contain any red blood cells, which means the oxygen still can’t get to the tissues

Blood transfusion (real blood from another human donor); they do have red blood cells