Blood (originated from hemocytopoietic tissue) is a highly specialized tissue made up of some types of cells, which make up the figurative part, dispersed in a liquid medium - the plasma - which corresponds to the amorphous part. The cellular constituents are: red blood cells (also called red blood cells or erythrocytes); white blood cells (also called leukocytes).
Plasma is mainly composed of water with various dissolved substances, which are transported through the body's vessels.
All blood cells originate in the red bone marrow from the pluripotent undifferentiated cells (stem cells). As a consequence of the process of cell differentiation, undifferentiated daughter cells assume specialized forms and functions.
Platelets are cellular debris originated from the fragmentation of giant bone marrow cells known as megakaryocytes. They have active substances in the process of blood clotting, so they are also known as thrombocytes (from Greek, thrombos = clot), which prevent the occurrence of bleeding.
Red blood cells
Red blood cells, red blood cells or erythrocytes (from Greek, eruthros = red, and kutes = cell) are anucleated, have a biconcave disc appearance and a diameter of about 7.2 m m. They are rich in hemoglobin, the protein responsible for oxygen transport, the important function of red blood cells.
White blood cells
White blood cells, also called leukocytes (from the Greek, leukós = white), are blood cells involved with the body's defense.
This activity can be exerted by phagocytosis or by producing defense proteins, the antibodies.
White blood cells are usually classified according to the presence or absence in their cytoplasm of specific granules and agranulocytes, which do not contain specific granulations common to any cell.
|White blood cells||Characteristics||Occupation|
|Cell with diameter between 10 and 14 mm; low bulk nucleus, containing 2 to 5 lobes, linked by chromatinic About 55% to 65% of white blood cells.||They act actively in the phagocytosis of invading microorganisms from the emission of pseudopods. They are the first line of defense of the blood.|
Cell with diameter between 10 and 14 mm, nucleus containing two lobes. About 2% to 3% of total leukocytes.
|Phagocytic cells. Acting on allergic diseases. Abundant in defense against various parasites.|
|Cell with diameter ranging between 10 and 14 mm. Large S-shaped nucleus About 0.5% of total white blood cells.||They are believed to act in allergic processes, such as mast cells.|
|Cell with diameter ranging from 8 to 10 mm. Two basic types: B and T. Spherical core. About 25% to 35% of total leukocytes.|
Responsible for the body's immune defense. B lymphocytes differentiate into plasma cells, the antibody-producing cells.
T lymphocytes mature in the thymus, a gland located in the chest.
|Cell with diameter between 15 and 20 mm. Horseshoe core. About 10% of total white blood cells.||They are believed to cross the walls of blood capillaries and, in tissues, differentiate into macrophages or osteoclasts, cells specialized in phagocytosis.|