Updated: Mar 19
To be a Phlebotomy Tech you must know the Blood
When studying to be a phlebotomy Technician you will be required to know the basic elements of the blood. Studying the blood may be difficult for some people as it requires some abstract thought because the components of blood are microscopic, meaning that you cannot see them with the naked eye. To understand the blood you have to imagine what is happening at the microscopic level and apply it to things you already know, but may not understand. For example, we all know that if we get a cut and it bleeds you have to apply pressure to the wound to stop the bleeding. However, we may not know how exactly the blood stops itself from flowing out of the body. The body stops bleeding by the use of thrombocytes or platelets. Platelets clot the blood preventing bleeding inside or outside the body. Understanding the elements of the blood will help you master the theory aspect of phlebotomy in addition to growing your overall medical understanding.
Getting to the Basic Elements of the blood
The blood is considered the largest connective tissue in the human body. This is because blood has all three necessary components of connective tissue. It has a ground substance (a substance that fills up space between fibers) which is the plasma, it has Fibers and Cells. The cells in the blood are also called the formed elements. Plasma makes up 55% of the blood. Formed Elements make up 45% of blood Plasma is composed of 90% water and 10% Solutes (proteins and other substances). Formed elements are composed of 99% Red blood Cells and less than 1% White blood cells and platelets.
Red & White Blood Cells
Another word for a red blood cell is an erythrocyte. Red blood Cells provide a vital function for the body. RBC’s transport oxygen and carbon dioxide through the body to every tissue and organ. They are able to transport oxygen due to a substance called oxyhemoglobin. They can transport carbon dioxide due to the presence of deoxyhemoglobin. They also help remove waste in the blood.
Leukocyte is another term for white blood cells. White blood cells also perform a very important function for the human body. The function for WBC’s is fighting parasitic, fungal and bacterial infections. They also play a role in allergic reactions and the release of heparin and histamine which prevents the blood from clotting and increases the diameter of blood vessels.
There are 5 types of Leukocytes (WBC)
Basophils (release heparin and histamine)
Eosinophils (Fights parasites and aid in allergic reactions)
Neutrophils (Fights bacterial and Fungal Infections)
Monocytes (Recognizing pathogens)
Lymphocytes (T cells, B cells, Natural Killers)
There is two substances you need to be familiar with while working as a phlebotomist. These substances are plasma and serum. Plasma can be obtained by obtaining blood in a collection tube and centrifuging it for 15 mins. The serum can be obtained the same way however before you centrifuge the blood you let to sit for 30 to 45 mins. Once the blood has collected and it has sat for the required time then it is to be placed in the centrifuge machine you will then be able to obtain serum.
The last and final thing you need to know about the blood is the blood types. To condense it as much as possible the basic information you need to know is:
Presence of RH antigen = Positive blood type
Absence of RH antigen = Negative blood type
O blood types are universal Donors
AB are universal Receivers
Positive Blood types can receive both positive and negative blood of that type.
Negative blood types can receive only negative of that blood type.