Eosinophils are particularly abundant in the connective tissue of the intestinal lining and at sites of chronic inflammation, such as lung tissues of asthma patients.Ultrastructurally the eosinophilic specific granules are seen to be oval in shape, with flattened crystalloid cores containing major basic proteins.Eosinophils are relatively less numerous than neutrophils, constituting only 1%-4% of total leukocytes.Eosinophils are granulocytes with a bilobed nucleus that can be differentiated from other leukocytes based on the presence of abundant large, acidophilic specific granules typically staining pink or red.Granulocytes are further divided into eosinophils, neutrophils, and basophils depending on their reaction to different dyes.The cell contains Golgi complexes and rough ER that are poorly developed, with few mitochondria mainly needed for glycolysis to meet their energy needs.All granulocytes are differentiated cells with a life span of only a few days.Granulocytes are a group of white blood cells that are characterized by the presence of cytoplasmic granules.Leukocytes are separated into two major groups granulocytes and agranulocytes, based on the density of their cytoplasmic granules.These cells play an essential role in phagocytosis and immunity and therefore in defense against infection.The normal concentration of WBCs in human blood varies between 4000 and 10,000 per microliter.White blood cells (WBC) or leukocytes are a heterogeneous group of nucleated cells that are found in the blood that are primarily involved in the various activities related to immunity.The cells also collect the generated carbon dioxide from the periphery and return it to the lungs for elimination from the body.RBCs transport oxygen from the lungs to the peripheral tissues to assist in metabolic processes such as ATP synthesis.The cytoplasm of erythrocytes lacks all organelles but is densely filled with hemoglobin, which allows the transportation of respiratory gases.The cytoskeleton is composed of proteins like spectrin, actin, band 3, protein 4.1, and ankyrin, which allows for cellular structural integrity as well as malleability.A phospholipid bilayer membrane supports the structure of the red blood cell, which is maintained by a network of proteins that make up the cytoskeleton.The plasmalemma consists of about 40% lipid, 10% carbohydrate, and 50% protein. The plasmalemma of erythrocyte, because it is readily available for study, is the best-known membrane of any cell.Erythrocytes are quite flexible, which permits them to bend and adapt to the small diameters and irregular shape of the blood vessels.The average concentration of erythrocytes in the blood is approximately 3.9-5.5 million per microliter (μL, or mm 3) in women and 4.1-6.0 million/μL in men.The biconcave shape of the cell provides a large surface-to-volume ratio and facilitates gas exchange.They are approximately 7.5 μm in diameter, 2.6-μm thick at the rim, but only 0.75-μm thick in the center. The mature human erythrocyte has a biconcave, discoid shape and is anucleated.The lifespan of red blood cells is about 120 days, and the development of red blood cells from stem cells occurs in about seven days via the process of erythropoiesis.Because of the lack of a nucleus, erythrocytes cannot divide and thus need to be continually replaced by new cells synthesized in the red bone marrow.
The cells have unique shape and composition which allow for these specialized cells to carry out their essential functions.Erythrocytes are the functional component of blood involved in the transportation of gases and nutrients throughout the human body.Red blood cells (RBCs) or erythrocytes are blood cells with terminally differentiated structures lacking nuclei and are filled with the O 2-carrying protein, hemoglobin.
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