Essentials Of Medical Physiology:Body Fluid:Anemia..كل ما تريد ان تعرفه عن الانيميا скачать в хорошем качестве

Essentials Of Medical Physiology:Body Fluid:Anemia..كل ما تريد ان تعرفه عن الانيميا

Essentials Of Medical Physiology:Body Fluid:Anemia The lecture file is written on my blog site on this site https://www.blogger.com/blog/posts/32...  INTRODUCTION. Anemia is the blood disorder, characterized by the reduction in: 1. Red blood cell (RBC) count. 2. Hemoglobin content. 3. Packed cell volume (PVC). Generally, reduction in RBC count, hemoglobin content and PCV occurs because of: 1. Decreased production of RBC. 2. Increased destruction of RBC. 3. Excess loss of blood from the body. All these incidents are caused either by inherited disorders or environmental influences such as nutritional problem, infection and exposure to drugs or toxins.  CLASSIFICATION OF ANEMIA. Anemia is classified by two methods: 1. Morphological classification. 2. Etiological classification. „ MORPHOLOGICAL CLASSIFICATION. Morphological classification depends upon the size and color of RBC. Size of RBC is determined by mean corpus- cular volume (MCV). Color is determined by mean corpus- cular hemoglobin concentration (MCHC). By this method, the anemia is classified into four types (Table 14.1): 1. Normocytic Normochromic Anemia. Size (MCV) and color (MCHC) of RBCs are normal. But the number of RBC is less. 2. Macrocytic Normochromic Anemia. RBCs are larger in size with normal color. RBC count is less. 3. Macrocytic Hypochromic Anemia. RBCs are larger in size. MCHC is less, so the cells are pale (less colored). 4. Microcytic Hypochromic Anemia. RBCs are smaller in size with less color. „ ETIOLOGICAL CLASSIFICATION. On the basis of etiology (study of cause or origin), anemia is divided into five types (Table 14.2): 1. Hemorrhagic anemia. 2. Hemolytic anemia. 3. Nutrition deficiency anemia. 4. Aplastic anemia. 5. Anemia of chronic diseases. 1. Hemorrhagic Anemia. Hemorrhage refers to excessive loss of blood (Chapter 115).Anemia due to hemorrhage is known as hemorrhagic anemia. It occurs both in acute and chronic hemorrhagic conditions. Acute hemorrhage. Acute hemorrhage refers to sudden loss of a large quan- tity of blood as in the case of accident. Within about 24 hours after the hemorrhage, the plasma portion of blood is replaced. However, the replacement of RBCs does not occur quickly and it takes at least 4 to 6 weeks. So with less number of RBCs, hemodilution occurs. How­ ever, morphologically the RBCs are normocytic and normochromic. Decreased RBC count causes hypoxia, which stimulates the bone marrow to produce more number of RBCs. So, the condition is corrected within 4 to 6 weeks. Chronic hemorrhage. It refers to loss of blood by internal or external bleeding, over a long period of time. It occurs in conditions like peptic ulcer, purpura, hemophilia and menorrhagia. Due to continuous loss of blood, lot of iron is lost from the body causing iron deficiency. This affects the synthesis of hemoglobin resulting in less hemoglobin content in the cells. The cells also become small. Hence, the RBCs are microcytic and hypochromic (Table 14.2). 2. Hemolytic Anemia Hemolysis means destruction of RBCs. Anemia due to excessive hemolysis which is not compensated by increased RBC production is called hemolytic anemia. It is classified into two types: A. Extrinsic hemolytic anemia: It is the type of anemia caused by destruction of RBCs by external factors. Healthy RBCs are hemolized by factors outside the blood cells such as antibodies, chemicals and drugs. Extrinsic hemolytic anemia is also called autoimmune hemolytic anemia. : Extrinsic hemolytic anemia:common causes: i. Liver failure. ii. Renal disorder. iii. Hypersplenism. iv. Burns. v. Infections like hepatitis, malaria and septicemia. vi. Drugs such as penicillin, antimalarial drugs and sulfa drugs. vii. Poisoning by chemical substances like lead, coal and tar. viii. Presence of isoagglutinins like anti-Rh. ix. Autoimmune diseases such as rheumatoid arthritis and ulcerative colitis. B. Intrinsic hemolytic anemia: It is the type of anemia caused by destruction of RBCs because of the defective RBCs. There is production of unhealthy RBCs, which are short lived and are destroyed soon. Intrinsic hemolytic anemia is often inherited and it includes sickle cell anemia and thalassemia.