LET'S OBSERVE THE
By Daniela Tagliasacchi and Giorgio Carboni, April 1997
Drawings of Michele Pirazzini
Thanks to Pasquale Chieco for his help in making the pictures
Translation revised by David W. Walker
INTRODUCTIONTHE PLASMATHE HEMATIC CELLSErythrocytesPlateletsLeukocytesPREPARATION OF THE BLOOD SMEARMaterialsTaking the bloodMaking the smearFixingStainingCheckingCover-slipping | OBSERVATIONErythrocytes (red cells)PlateletsLeukocytes (white cells)GranulocytesNeutrophilEosinophilBasophilLymphoid cellsLymphocytesMonocytesCONCLUSIONBIBLIOGRAPHY |
What are blood cells? What do they look like? What functions do they perform? How can I recognize the different categories? This is a short description of the blood cells and includes a simple experiment which allows you to become familiar with the cells of this precious liquid.
The blood consists of a suspension of special cells in a liquid called plasma. In an adult man, the blood is about 1/12th of the body weight and this corresponds to 5-6 litres. Blood consists of 55 % plasma, and 45 % by cells called formed elements.
The blood performs a lot of important functions. By means of the hemoglobin contained in the erythrocytes, it carries oxygen to the tissues and collects the carbon dioxide (CO2). It also conveys nutritive substances (e.g. amino acids, sugars, mineral salts) and gathers the excreted material which will be eliminated through the renal filter. The blood also carries hormones, enzymes and vitamins. It performs the defense of the organism by mean of the phagocitic activity of the leukocytes, the bactericidal power of the serum and the immune response of which the lymphocytes are the protagonists.
Cells free serum or plasma, can be obtained by centrifugation. The plasma is a slightly alkaline fluid, with a typical yellowish color. It consists of 90 % water and 10% dry matter. Nine parts of it are made up by organic substances, whereas...