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It is time for you to know the application that led us to see cells and count them. Our blood is a tissue because, although it is liquid, it is made up of different cell types. For instance, red blood cells that carry oxygen throughout our body and white blood cells that serve as protection since they are part of our immune system.
Hematology is a medical discipline responsible for the study of blood, so it is called because hemato is derived from the Greek haimato which means "blood" and logy that means "study of". Now you can understand terms like hematoma which means bruise.
In routine clinical studies, a complete blood count is required, that is, a count of the total number of cells in the blood. This study consists in to count red blood cells, white blood cells, and, in addition to determining the amount of hemoglobin in the blood and the fraction (or proportion) of red blood cells in the blood (known as hematocrit). The blood count also tells us the size of the red blood cells and allows us to count platelets. Platelets are disc-shaped fragments of bone marrow cells circulating in blood that help with clotting and healing processes.
How do you imagine someone being able to count blood cells? What tools do we need? Of course, a microscope.
To perform the test, a drop of blood is required. The blood is placed on a slide, which is a rectangular glass specifically designed to place the samples and observe them under a microscope.
Although some cells, such as red blood cells (which are also known as erythrocytes) can be seen without be stained with a dye, staining methods are important. One of the more used is the Wright technique, developed in 1902 by James Homer Wright. With this technique we can not only simply count the cells, but also identify problems with their shape.
With this technique, the nuclei appear purple and the red blood cells appear pink. An important aspect to keep in mind is that red blood cells do not have a nucleus, so it is very easy to distinguish them from white blood cells.
To count the cells in the blood, it is necessary for a specialist to use a Neubauer chamber, very similar to a slide but with the modification of having small squares where we can count the number of cells per quadrant to make the final calculation of the total cell number.
In adults, men have from 4.35 to 5.65 million red blood cells and women between 3.92 and 5.13 million red blood cells per microliter of blood. Adults have a total blood volume of about 6 liters to 6,000,000 microliters!
Another important value is that red blood cells represent 42 to 54% for men, and 38 to 46% for women of the total cells in the blood. This value is known as hematocrit.
When, along with other parameters, the amount of red blood cells in the blood is less than the established values, the person is diagnosed with anemia. Another disease in which the number of cells in the blood is altered is leukemia, where there are many white blood cells (also called leukocytes), in adults the normal number of leukocytes is 4,500 and 11,000 units per cubic millimeter of blood.
Because red blood cells carry oxygen to our tissues, there are conditions that can increase the number of these cells, such as smoking, some lung diseases, and dehydration.
What did you think about how wonderful and complex it is to see blood under the microscope?
We recommend some videos for you to see red blood cells:
Look at the following link to see how red blood cells are counted