Chapter 12: Blood Blood composition: Blood, a type of _Connective__ tissue, is a complex mixture of what three things?_Cell, fragments, dissolved biochemichals_ Functions: What are the functions of blood? _transports substances, helps to maintain a stable environment in the body fluids, and distributes heat___ ________________________________________________________________________________________ Blood Cells: The blood includes what three types of cells and fragments? red blood cells, white blood cells, platelets A blood sample is normally __45__% cells and __55__% plasma. Red Blood Cells (RBCs, erythrocytes): RBCs are _bioconcave__ disks that contain one-third oxygen-carrying _hemglobin__ 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 __nucleu sduring development, so they cannot reproduce or produce proteins. RBC Counts: What is a typical RBC count for males? _4.6 to 6.2 million/mm^3_ For females? _4.2-5.4 million/mm^3_ 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 __erythropoetin_, 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 __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? _The heme is converted into biliverdin, some of which becomes bilirubin; these pigments are excreted in the bile. Iron is recycled to be incorporated into new red blood cells._ 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 _________ 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, lymphocytes_ What is the basic function of the white blood cells? _Protection of the body, by defending against infection and disease._____________________________________________ Granulocytes: Why is this group called granulocytes? _Granules are visible in their cytoplasm when stained with certain stains. Neutrophils: Neutrophils have _red staining_-staining fine cytoplasmic granules and a _2__ to _5__-lobed nucleus; they comprise _54 to 62__ percent of leukocytes. What is their function? __To phagocytize bacteria, fungi, and some viruses. What is diapedesis? __Squeezing of some WBCs between cells in blood vessel walls.__ Eosinophils: Eosinophils have coarse granules that stain deep blue, a _bi-lobed_-lobed nucleus, and make up only _1 to 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 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. 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. _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, regulate 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 bleeding__. 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 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. factors leading to the production of _prothrombin__ activator. This activator converts inactive __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? _both type A and type 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 fetalis__ 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. 5 © 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.