Blood PDF

# Blood The image is a blood themed graphic with the word "Blood" written in a gothic font surrounded by dripping red blood. ## Blood - It is a specialized connective tissue that circulates in a closed system of blood vessels. ## The Components of Blood - It is made up of suspensions of forme...

# Blood The image is a blood themed graphic with the word "Blood" written in a gothic font surrounded by dripping red blood. ## Blood - It is a specialized connective tissue that circulates in a closed system of blood vessels. ## The Components of Blood - It is made up of suspensions of formed elements in a yellow fluid called plasma. ### Composition of Blood The blood is made up of 55% plasma and 45% formed elements. - **Plasma** is the liquid component of blood, and it is made up of water, proteins, and other dissolved substances. - **Formed elements** include red blood cells, white blood cells, and platelets ### Plasma components - **Albumin:** (54%) - **Globulin:** (38%) - **Fibrinogen:** (7%) - **Immunoglobulin & other:** (1%) ### Formed Elements - **Erythrocytes (RBC), the red blood cells** - **Leukocytes (WBC), the white blood cells** - **Granulocytes**, have granules in their cytoplasm - **Neutrophils** are the most common type of white blood cell. They are responsible for killing bacteria and other pathogens. - **Eosinophils** are involved in the allergic response and in fighting off parasitic infections. - **Basophils** are involved in the inflammatory response. - **Agranulocytes**, lack granules in their cytoplasm - **Lymphocytes** are responsible for immunity. - **Monocytes** are involved in the phagocytosis of pathogens. - **Thrombocytes (Platelets)** are cell fragments that help stop bleeding. ## Blood Functions - Transport oxygen from lungs to tissue and carbon dioxide from tissues to lungs. - Transport formed metabolic waste to lungs, kidneys, skin, intestines for excretion. - Carry absorbed nutrients to liver & other body tissues. - Regulate water balance. - Regulate body temperature. - Transport hormones, vitamins, salts. - Transport metabolites. - Provide protection against infection through WBC and antibodies. - Help in the maintenance of normal acid-base balance. - Blood itself helps coagulation through internal factors and stop bleeding. ## Hemopoiesis (Haematopoiesis) - It is a process of blood cells development. - RBC, WBC & platelets are formed into bone marrow. - The active cellular marrow is Red bone marrow & inactive cellular marrow is White bone marrow. - The blood cells are derived from stem cells called hematopoietic stem cells. ## Erythrocytes (RBC) - Erythrocytes (RBC) are formed from proerythroblast. - Derived from hematopoietic stem cells. - **Characteristic:** Contains hemoglobin. - **Shape:** Biconcave Disc. - **Size:** Diameter = 7-8 mm. - **Thickness:** About 2 mm. - Erythrocytes are biconcave discs with no nucleus, and they carry oxygen. ## Hemoglobin - It is conjugated protein synthesized inside immature erythrocytes in red bone marrow. - Each Hb molecule is made up of two portions: - **Globin (protein):** portion 01 unit. - **Haem (non protein, ion containing):** Portion 04 units. - Haem contains an iron ion that combines reversibly with one oxygen molecule. - Each RBC contains about 280 millions Hb molecules. - These Hb molecules are enclosed in a membrane called stroma. - The iron containing haem imparts red color to Hb. ### Reactions with Hemoglobin - **Hb + O₂ → Oxyhaemoglobin** - **Hb + CO₂ → Carboxyhaemoglobin** ### Normal Range of Hemoglobin - **Infants:** 14-20 gm/dl - **Adult male:** 13.5-18 gm/dl - **Adult female:** 12 - 16 gm/dl ## Transport of Oxygen in Blood - Normally about 97% of oxygen is transported from lungs to tissues is carried in combination with Hb. - Oxygen molecules combines loosely and reversibly with the haem portion of Hb. - When oxygen concentration is high in a particular tissue, it binds with oxygen and when oxygen concentration is low, it releases oxygen. - Around 15 gm of Hb is present in each 100 ml of blood and each gm of Hb can combine a maximum of 0.34 ml of oxygen. - Carbon dioxide, collected from tissues, binds with Hb to form carbamino-haemoglobin, released in lungs. ## Functions of RBC - Transportation of oxygen from lungs to tissue and carbon dioxide from tissues to lungs. - Helps in blood group determination. - Act as a buffer by the action of Hb. ## Disorders Related to Hemoglobin & RBC - **Anemia:** The anemia refers to decreased oxygen-carrying capacity of the blood which may be due to deficiency of RBC. There are several types of anemia, as follows - - **Aplastic anemia:** Due to lack of bone marrow functioning, insufficient RBC. - **Blood loss anemia:** Due to rapid hemorrhage. - **Megaloblastic Anemia:** Due to deficiency of Vitamin B₁₂ and folic acid. - **Hemolytic anemia:** Due to Hb defects, defects of RBC membrane, and abnormal RBC enzymes. - **Iron Deficiency Anemia:** Inadequate absorption or excessive loss of iron. - **Sickle cell anemia:** - Due to a genetic mutation that causes substitution of one wrong amino acid in a particular portion of globins. - At low oxygen concentration in many capillaries Hb molecules combines with each other to form fiber-like structure to distort erythrocyte membrane to form sickle shape. - Such sickle RBC occludes and bursts into capillaries, leading to anemic condition. - **Haemolysis** is a condition where Hb is liberated in plasma, due to the breakdown of erythrocytes. - **Reasons:** Hypotonic saline solution, solvents like chloroform, ether etc, bile salt, saponins, some drugs like quinine, nitrates etc, Viper venom, externally vigorous shaking etc. - **Polycythemia** is a blood disorder where concentration of RBC increases in blood due to increased RBC production, decreased volume of fluid part of the blood, etc. ## Leukocytes (WBC) - These are nucleated non-Hb containing cells derived from hemopoietic stem cells in red bone marrow. - Normal WBC count is 4000 to 10000 cells per mm³. ### Granulocytes - About 75% of total WBC. As these cells are having many different shapes nuclei, they are also known as polymorphs. The cells can be divided into three types, depending upon characteristics of granule - **Acid dye/ Eosin coloration:** Eosinophils or acidophils. - **Alkaline or base dye coloration:** Basophils. - **No dye coloration:** Neutrophils. ### Agranulocytes - About 25% of total WBC. ## Neutrophils - 60-70% of total WBC. - Usually 1-4 lobed nucleuses. - Diameter 10-12 μm. ### Functions of Neutrophils - Move toward the site of infection. - Actively phagocyte the microorganism. - Large no. of proteolytic, amylolytic and lipolytic enzyme for phagocytosis. - Effective against parasitic infections. ## Eosinophils - 02-04% of total WBC. - Usually, 2 lobed nucleuses. - Diameter 10-12 μm. ### Functions of Eosinophils - Move toward the site of infection for the release of enzyme like histaminases. - Phagocytosis of antigen antibody complex. - Effective against parasitic infections. ## Basophils - 0.5 - 01% of total WBC. - Irregular, usually bilobed nucleus. - Diameter 8-10 μm. ### Functions of Basophils - Move toward the site of infection, converts into mass cells. They increase overall inflammatory response. - At the site of infection these mass cells release histamine, serotonin, and heparin that attract other WBC to the site of infection. ## Agranulocytes - There is a presence of very small sized granules in the cytoplasm, poor to stain by dyes, which cannot be seen by light microscope, hence called agranulocytes. - About 25% of total WBC. ## Lymphocytes - 20-25% of total WBC. - Rounded nucleus. - Diameter 9-14 μm. ### Functions of Lymphocytes - **B lymphocytes:** For the formation of antibodies. - **T lymphocytes:** For cellular immunity. ## Monocytes - 03-08% of total WBC. - Oval or kidney-shaped nucleus. - Diameter 12-20 μm. ### Functions of Monocytes - Monocytes convert into macrophages, which are highly phagocytic. ## Blood Group & Transfusion - Taking out blood from one person and injecting it into the vein of another is called as blood transfusion. - The person who donates blood is known as a **Donor**. - The person who receives blood is known as a **Recipient**. - Blood group is decided by the presence of certain red blood cells antigen which is called as blood group factors and resides on the surface of RBCs membrane. - These are lipoproteins or glycoproteins. - The antigenic character or RBC are inherited and antigen detection of all blood group is depends upon the principle of haem- agglutination reaction. - In this reaction, the red cell **antigen** is referred to as the **agglutinogen** while the **antibody** is called as the **agglutinin**. - There are two types of antigens (agglutinogen): type A and type B. - With the help of these, the ABO system can determine or classify blood group into four major groups: A, B, AB and O. - The reaction that occurs when mixing RBCs with reagents like anti-A and anti-B determines the blood group. ### Blood Group Types - **Blood group A** - Antigen A is present on RBC and the serum contains anti B antibodies. - **Blood group B** - Antigen B is present on RBC and the serum contains anti A antibodies. - **Blood group AB** - Antigen A & B are present on RBC but the serum contains NO antibodies. This blood group is compatible with all groups therefore known as **Universal recipient**. - **Blood group O** - Antigen is NOT present on RBC and the serum contains anti A & B both antibodies. Because people with blood group O do not have any type of antigen on RBC, those with this blood type are known as **Universal donor**. People with blood group O can receive blood only from blood group O. ## Rhesus Blood Group System (Rh factor) - This is an important system named after the antigenic factor which was first observed on RBC of rhesus monkeys in 1940. - About 85% of human beings are Rh+ve, the remaining Rh-ve. - Anyone who possesses this antigen on RBC is termed Rh positive, whereas the person who does not have this antigen are said to be Rh negative. - When Rh negative person receives blood from Rh positive, anti Rh agglutinin develops slowly. - It creates Rh negative person strongly sensitive to Rh factor, further transfusion of Rh positive blood into the same person leads to severe conditions. ## Haemolytic Disease of Newborn (Erythroblastosis Fetalis) - This disease is characterized by agglutination and phagocytosis of red blood cells. - If a women possesses Rh negative blood and her husband is Rh positive, the fetus will have strong possibilities for the father's dominating Rh positive factor. - However, if a small amount of Rh positive blood leaks from the fetus, through the placenta into the blood stream of Rh negative mother, anti Rh antibodies are synthesized in mother's blood. - **First Pregnancy:** The mother's body may develop anti-RH antibodies, but these will not affect the first baby. - **Second Pregnancy:** When a woman is exposed again to an Rh positive fetus, the antibodies cross the placenta and attack the baby. - **Hemolytic jaundice** may occur in the baby. ## Homeostatic - It is a procedure for blood loss prevention. - There are several mechanisms involved in blood loss prevention: - **Vascular spasm:** Immediately after blood vessels are cut or ruptured, the stimulus causes the wall of vessels to contract due to nervous reflexes, local spasmogenic., and local humerous factor which slows the flow of blood in the affected area. - **Formation of Platelet plug:** Platelets are non-nucleated cells that help stop bleeding. They adhere to the injured area and release chemicals that activate other platelets. This forms a plug that helps to stop the bleeding. - **Blood coagulation:** The coagulation reaction of plasma to injury occurs when plasma comes into contact with foreign substances. - **Fibers (fibrin)** develop which forms a network to form a clot that sticks to the injured surface. This seals the puncture and stops bleeding - **Coagulation Factors:** There are 12 coagulation factors present in circulatory plasma in inactive form. - **Prothrombinase** forms first, converting prothrombin to thrombin. Thrombin then converts fibrinogen to fibrin, which forms a clot. This process is aided by a process called the coagulation cascade. - There are two pathways involved in the coagulation cascade - **Intrinsic pathway:** It is a complex slow process where the activators are located within the blood. - **Extrinsic pathway:** This pathway utilizes a protein called tissue factor that is located outside the body. - **Vitamin K:** Plays an important role in the production of prothrombin, factor VII, factor IX, and factor X. - **Clot formation:** Blood cells, platelets and plasma are entrapped in strengthened fibrin fibers, which attaches to damaged surface of blood vessels. This composite is called as blood clot. After a few minutes, the clot begins to contract and most of the fluid is expressed off. This extracted fluid (from which all of its fibrinogen and other clotting factors are removed) is called serum. ## Platelet (Thrombocytes) - Hemopoietic stem cells also differentiate into cells that produce platelets. - Under the influence of the hormone thrombopoietin, myeloid stem cells develop into megakaryoblasts. - Megakaryoblasts transform into megakaryocytes, huge cells that splinter into 2000 to 3000 fragments. Each fragment, enclosed by a piece of the plasma membrane, is a Platelet (Thrombocytes). - Normal value - 150000 to 400,000/ µL of blood. ## Disorders Related to Platelets & Clotting - **Thrombocytopenia:** It is the disorder where the platelet count falls down leading to bleeding into the skin and internal organs. - **Causes of Thrombocytopenia:** Thrombocytopenia may be caused either by a failure of bone marrow to produce platelets, or by excessive destruction of platelets in the spleen. - **Major Symptoms:** Easy bruising, a rash of many tiny red dots or large purple patches, sometimes heavy nose bleeds and many times bleeding gums. - **Women:** In women, it may be associated with heavy menstrual bleeding. - **Stroke:** Even chances of stroke are increased due to the bleeding in the brain. ## Hemophilia - This disease refers to the inherited deficiencies of blood clotting factors, which causes excessive bleeding. - **Causes:** The disease is caused due to deficiency of a protein involved in blood clotting. - **Factor VIII:** Absent in hemophilia. - **Symptoms:** Major complications include easy bruising, sudden painful swelling of muscles, as well as joints, because of the internal bleeding. - **Blood in Urine:** Blood is many times observed in urine. - **Injury:** Injury is always associated with prolonged bleeding. ## Blood Donation The last two images are a call to action for blood donation. They depict slogans in red, with drops of blood and illustrations of arms giving blood. The slogans are: - Be a Hero, Give Blood. - Let's Create Blood Relations.