Презентация на тему: "Презентация по английскому языку "Blood and blood cells""
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Blood
Blood is a body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those cells.
In vertebrates, it is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains proteins, glucose, mineral ions, hormones, carbon dioxide, and blood cells themselves. Albumin is the main protein in plasma, and it functions to regulate the osmotic pressure of blood.
Supply of oxygen to tissues
Supply of nutrients such as glucose, amino acids, and fatty acids (dissolved in the blood or bound to plasma proteins)
Removal of waste such as carbon dioxide, urea, and lactic acid
Immunological functions, including circulation of white blood cells, and detection of foreign material by antibodies
Coagulation, the response to a broken blood vessel, the conversion of blood from a liquid to a semisolid gel to stop bleeding
Messenger functions, including the transport of hormones and the signaling of tissue damage
Regulation of core body temperature
Blood performs many important functions
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A blood cell, also called hemocyte, or hematocyte, is a cell produced through hematopoiesis and found mainly in the blood.
Major types of blood cells include:
Red blood cells (erythrocytes)
White blood cells (leukocytes)
Platelets (thrombocytes)
Blood cells
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Red blood cells
Red blood cells or erythrocytes, primarily carry oxygen and collect carbon dioxide through the use of hemoglobin.
RBCs are formed in the red bone marrow from hematopoietic stem cells in a process known as erythropoiesis. In adults, about 2.4 million RBCs are produced each second. RBCs have a lifespan of approximately 100-120 days. After they have completed their lifespan, they are removed from the bloodstream.
Mature red blood cells are unique among cells in the human body in that they lack a nucleus (although erythroblasts do have a nucleus). Red blood cells are disk-shaped and deformable to allow them to squeeze through narrow capillaries. Red blood cells are much smaller than most other human cells.
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White blood cells
White blood cells or leukocytes, are cells of the immune system. They are produced and derived from multipotent cells in the bone marrow known as a hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system. There are a variety of types of white bloods cells that serve specific roles in the human immune system. WBCs constitute approximately 1% of the blood volume.
White blood cells are divided into granulocytes and agranulocytes, distinguished by the presence or absence of granules in the cytoplasm. Granulocytes include basophils, eosinophils, neutrophils. Agranulocytes include lymphocytes and monocytes.
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Platelets, or thrombocytes, are very small, irregularly shaped clear cell fragments, 2–3 µm in diameter, which derive from fragmentation of megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days. They circulate in the blood of mammals and are involved in hemostasis, leading to the formation of blood clots. Platelets release thread-like fibers to form these clots.
If the number of platelets is too low, excessive bleeding can occur. However, if the number of platelets is too high, blood clots can form thrombosis, which may obstruct blood vessels and result in such events as a stroke or myocardial infarction.
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A blood type (also called a blood group) is a classification of blood, based on the presence and absence of antibodies and antigens on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system.
Blood types are inherited and represent contributions from both parents.
BLOOD TYPES









