Chapter 8 Forensic Serology - Weebly
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8-1 ©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE: An Introduction, 2 nd ed. By Richard Saferstein Chapter 8 Forensic Serology Courtesy of C. Fanning
Transcript of Chapter 8 Forensic Serology - Weebly
8-1©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Chapter 8 Forensic Serology
Courtesy of C. Fanning
8-2©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Nature of Blood
•The word ______ refers to a highly complex mixture of cells, enzymes, proteins, and inorganic substances.•Plasma, which is the fluid portion of blood, is composed principally of ________.•Red blood cells (erythrocytes), white blood cells (leukocytes), and platelets are the solid materials suspended in plasma.•Antigens, usually proteins, are located on the surface of red blood cells and are responsible for _________ characteristics.
8-3©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Nature of Blood
8-4©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Blood Cellsn Blood cells are formed in the __________.
All blood cells arise from the same bone marrow stem cells. Stem cells are immortal, meaning they never die (at least not until you do).
n Stem cells are also _____________ meaning they have not yet developed into a particular cell type. Furthermore, stem cells are pluripotent, meaning they have the potential to become any type of blood cell. These immortal, undifferentiated, pluripotent stem cells give rise to erythrocytes, leukocytes and platelets.
8-5©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Leukocytes: Types and namesn The diagram below illustrates the
different types of blood cells. Leukocytes, also known as white blood cells, are a group of related cell types that involved in immune function.
n Leukocytes include neutrophils, eosinophils, basophils, lymphocytes and monocytes.
8-6©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Leucocytes: White Blood Cells and Erythrocytes : Red Cells
8-7©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Erythrocytes: Red Cellsn Erythrocytes, also known as red
blood cells (RBCs), function to transport ________ in the blood. The shape of erythrocytes is ideal for this function, they are biconcaved discs.
n This shape increases the surface area-to-volume ratio of the cell, thus increasing the efficiency of diffusion of oxygen and carbon dioxide into and out of the cell. They have a flexible plasma membrane. This feature allows erythrocytes, which have a 7µm diameter, to squeeze through capillaries as small as 3 µm wide.
8-8©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Red Blood Cells – cont.
n Erythrocytes contain tremendous amounts of ___________, the protein that binds oxygen. In order to make room for more hemoglobin to carry more oxygen, erythrocytes loose their nucleus and other organelles as they develop in the bone marrow. Because they lack a nucleus and other cellular machinery, erythrocytes cannot repair themselves when damaged, consequently they have a limited life span of about _____ days.
8-9©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Erytropoesis: Production of Blood Cellsn The removal of old and dying erythrocytes is
carried out by the ______. Erythrocytes, which represent the most numerous cell type in the body die at a rapid rate: 2-3 million erythrocytes die every second. Erythrocyte production must equal erythrocyte death or the cell population would decline. Erythrocytes are produced through a process called erythropoesis.
8-10©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Hematocrit n Whole blood is composed of plasma
(liquid), cells and platelets. If whole blood is placed into a tube and centrifuged, the cells and the plasma will separate.
n The erythrocytes will pack into the bottom of the tube, the plasma will be at the top of the tube, and the leukocytes and platelets will form a thin layer in the middle.
n The hematocrit is defined as the ___________ of whole blood made up of erythrocytes.
8-11©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
FORENSIC SCIENCE: An Introduction, 2nd ed.By Richard Saferstein
Hematocrits vary by Gendern This value is determined by dividing the
height of the erythrocytes by the total height of the blood in the tube and multiplying by 100.
n Hematocrits vary but there is a range of values that is considered normal. Average hematocrit values are: n males.......... 40-50% n females....... 38-45% n athletes........ > 50%
n Any activity or condition that consistently lowers oxygen levels in the blood will cause an increase in erythropoesis and a subsequent rise in the hematocrit.
