Chapter 12: Blood Blood composition: Blood, a type of _connective________ tissue, is a complex mixture of what three things?__cells, fluid, and chemicals_______________________ ______________________________________________________________________________________________ Functions: What are the functions of blood? _it transports substances and maintains a stable environment_________________________________________________ ________________________________________________________________________________________ Blood Cells: The blood includes what three types of cells and fragments? Red blood cells, white blood cells, and platelets. A blood sample is normally 45_% cells and _55% plasma. Red Blood Cells (RBCs, erythrocytes): RBCs are _biconcave_ disks that contain one-third oxygen-carrying _Hemoglobin_by volume. When oxygen combines with hemoglobin, a bright red substance called _Oxyhemoglobin_ results. After releasing oxygen, the hemoglobin is darker, and is now called _Deoxyhemoglobin. Red blood cells discard their _Nucleus during development, so they cannot reproduce or produce proteins. RBC Counts: What is a typical RBC count for males? 4,600,000-6,200,000 per mm3 For females? 4,500,000-5,100,000 per mm3_ RBC production: In the embryo and fetus, red blood cell production occurs in the yolk sac, liver_, and spleen; after birth, it occurs in the red bone marrow. The average life span of a red blood cell is _120 days. Control of RBC Numbers: The total number of red blood cells remains relatively constant due to a _negative_ feedback mechanism utilizing the hormone _erythropoietin_, which is released from the kidneys. and liver in response to the detection of low _oxygen_ levels. Dietary Factors Affecting Red Blood Cell Production: Vitamins __B12 and _Folic_ acid are needed for DNA synthesis, so they are necessary for the reproduction of all body cells, especially in hematopoietic tissue. _Iron__ is needed for hemoglobin synthesis. A deficiency in red blood cells or quantity of hemoglobin results in a disorder called _anemia_. Destruction of Red Blood Cells: With age, red blood cells become increasingly fragile and are damaged by passing through _Narrow capillaries_. Macrophages in the _liver_ and _Spleen_ phagocytize damaged red blood cells. Hemoglobin from the decomposed red blood cells is split into _Heme_ and _globin. What happens to the heme and iron? Heme is decomposed into iron that is stored or recycled and biliverdin and bilirubin that are excreted in bile. 1 © 2018 by McGraw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. White Blood Cells (WBCs, Leukocytes): WBCs are formed from _ Hemocytoblasts stem cells in response to hormones when needed. Five types of white blood cells are present in circulating blood, and are distinguished by size, granular appearance of the cytoplasm, shape of the nucleus, and staining characteristics. Name these five types of WBCs: Neutrophils, Eosinophils, Basophils, Monocytes, and Lymphocytes What is the basic function of the white blood cells? _ Protect and defend against disease. Granulocytes: Why is this group called granulocytes? _Granules are visible in their cytoplasm when stained with certain stains._ Neutrophils: Neutrophils have _Red-staining fine cytoplasmic granules and a _2_ to _5_ multi-lobed nucleus; they comprise __54-62%_ percent of leukocytes. What is their function? To Phagocytize bacteria, fungi, and some viruses. What is diapedesis? _Squeezing of some WBC’S between cells in blood vessel walls. Eosinophils: Eosinophils have coarse granules that stain deep blue, a _bi-lobed_-lobed nucleus, and make up only _3_% of circulating leukocytes. What are their functions? _to moderate allergic reactions, defend against certain parasites . Basophils: Basophils have fewer, larger granules that stain _deep blue_; they account for fewer than 1_% of WBCs. Basophils produce chemicals; what are the functions of these chemicals? _To prevent blood clotting induce Inflammation and allergy and increase blood flow to damaged tissues. How do they help fight pathogens? By promoting inflammatory and allergic responses Agranulocytes: Why are they called agranulocytes? They lack the visible cytoplasmic granules that granulocytes have. Monocytes: Monocytes are the _largest_ blood cells, have _kidney_-shaped or _oval__ nuclei. They comprise _3_ to 9_% of circulating leukocytes. What is the function of the monocytes? To phagocytize bacteria and cellular debris. Lymphocytes: Lymphocytes are long-lived, have a large, _round_ nucleus, and account for _25_ to _33__% of circulating WBCs. What is their function? Involved in immune responses, antibody production, and attacks on specific foreign substances. WBC Counts: Normally a cubic milliliter of blood contains between _5,000_ & __10,000_ WBCs. A _differential_ white blood cell count can help pinpoint the nature of an illness, indicating whether it is caused by bacteria or viruses. This white blood cell count lists the percentages of each of the types of leukocytes in a blood sample. 2 © 2018 by McGraw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. _leukocytosis__ occurs after an infection when excess numbers of leukocytes are present. _leukopenia_ (too few WBCs) results from a variety of conditions, including AIDS. Platelets (thrombocytes): Blood platelets are fragments of large cells called _megakaryocytes_. Platelets help repair breaks in damaged blood _vessels__. Normal counts vary from __150,000_ to_350,000_ platelets per mm3. Plasma: Plasma is the clear, straw-colored fluid portion of the blood. Plasma is composed mostly of _water_, but contains a variety of substances. What are plasma’s functions? To transport nutrients and gases, regulates fluid and electrolyte balance, and maintain pH balance. Plasma proteins: The plasma proteins are the most abundant dissolved substances in the plasma. Briefly describe the functions of the following plasma proteins. Albumins: To maintain the correct osmotic pressure of the plasma Globulins: To transport lipids and fat-soluble vitamins, some are a type or antibody. Fibrinogen: Helps with blood coagulation Other Plasma Components: Nutrients and Gases. What are the two most important blood gases? _Oxygen and carbon dioxide_ The plasma nutrients include amino acids, monosaccharides, nucleotides, and lipids. Types of lipoproteins include HDL, LDL, VLDL, and chylomicrons. Nonprotein Nitrogenous Substances generally include amino acids, urea, uric acid, and creatinine. What are they derived from? Amino acids are the products of protein digestion. Urea is derived from products of protein metabolism, and uric acid comes from nucleic acid breakdown. Creatinine is a breakdown product of creatine from muscle tissue. Plasma electrolytes are absorbed by the intestine or are by-products of cellular metabolism. They include sodium, potassium, calcium, magnesium, chloride, bicarbonate, phosphate, and sulfate ions. Hemostasis: Hemostasis refers to the process that _Stop bledding_. Following injury to a vessel, three steps occur in hemostasis: blood vessel spasm, platelet plug formation, and blood coagulation. Trauma to, or cutting of a blood vessel, causes the muscle in its walls to contract, or engage in _Vasospasm_. This reflex lasts only a few minutes, but lasts long enough to initiate the second and third steps of hemostasis. Spasm of the injured vessel is followed by the formation of a platelet plug. Platelets stick to any _Rough surface, especially _collagen_ in connective tissue. A platelet plug is most effective on small vessels. Coagulation: Blood coagulation is the most effective means of hemostasis. It is a complex sequence of chemical reactions, involving several _clotting__ factors, and leading to the formation of a blood __clot__. Damaged tissues release a chemical called tissue _thromboplastin__________, which activates the first in a series of factors leading to the production of __prothrombin__ activator. This activator converts inactive 3 © 2018 by McGraw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. __Prothrombin_ in the plasma into active __thrombin_. This in turn, catalyzes a reaction that converts soluble _fibrinogen_ into netlike _fibrin__, causing the blood cells to catch in a meshwork of threads. Once a blood clot forms, it promotes still more clotting through a _positive__________ feedback system. After the clot forms, and healing has occurred, it will eventually be dissolved by the body. This requires the plasma protein __plasmniogen___ to be converted into active _plasmin_, which digests fibrin threads. A clot that forms abnormally in a vessel is a _thrombus_; if it dislodges, it is an _embolus_. Blood Groups and Transfusions: After mixed success with transfusions, scientists determined that blood was of different types, and only certain combinations were compatible. Clumping of red blood cells following a transfusion of mismatched blood is called __agglutination_. This clumping is due to the interaction of proteins on the surfaces of red blood cells, called _antigens_, with certain proteins, called _antibodies_, carried in the plasma. ABO Blood Group: What is an antigen? A special protein found on the surface of cells, that evokes an immune response. What is an antibody? A special protein in the blood plasma that interacts with a specific antigen, in order to destroy it or render it harmless. Type A has what type of antigens? _Type A antigens Antibodies? _anti-B antibodies_ Type B has what type of antigens? _type B antigens Antibodies? Anti-A antibodies Type AB has what type of antigens? _neither A nor B antigens Antibodies? Neither type of antibodies_ Type O has what type of antigens? _neither A nor B antigens_ Antibodies? Anti-A and anti-B blood antibodies RH Blood Group: The Rh factor was named after the _rhesus_ monkey. If the Rh factor surface protein is present on red blood cells, the blood is Rh _positive __; if not, it is Rh _negative_. There are no corresponding antibodies in the plasma unless a person with Rh-negative blood is transfused with Rh-positive blood; the person will then develop antibodies for the Rh factor. _erythroblastosis_ develops in Rh-positive fetuses of Rh-negative mothers, but can now be prevented. 4 © 2018 by McGraw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part.
