Copyright 2003 by Mosby, Inc. All rights reserved. CHAPTER 11 CIRCULATORY SYSTEM

Copyright 2003 by Mosby, Inc. All rights reserved. Structure and Function Structure of the circulatory system –Includes the blood and lymph that move through the body Function of the circulatory system –Both blood and lymph are tissues that maintain homeostasis and give the body immunity

Copyright 2003 by Mosby, Inc. All rights reserved. Blood Body contains approximately 4 to 5 liters of blood, making up about 8% of the body’s weight Functions include: –Transporting nutrients, oxygen, and hormones –Removing metabolic wastes and carbon dioxide –Providing immunity through antibodies –Maintaining body temperature and electrolyte balance –Clotting to prevent bleeding from a wound

Copyright 2003 by Mosby, Inc. All rights reserved. Red Blood Cells (Erythrocytes) Erythrocytes contain a protein called hemoglobin that carries oxygen to all cells and removes carbon dioxide Each red blood cell lives only 90 to 120 days New cells are manufactured by the red marrow or myeloid tissue in bones The liver and spleen remove dead red blood cells

Copyright 2003 by Mosby, Inc. All rights reserved. White Blood Cells (Leukocytes) White blood cells remove foreign particles, fight infection, and help prevent disease There are fewer white blood cells than red White blood cells are larger than red Leukocytes live about 9 days Pus consists of white blood cells mixed with bacteria

Copyright 2003 by Mosby, Inc. All rights reserved. Five Types of White Blood Cells Neutrophils Basophils Eosinophils Lymphocytes Monocytes

Copyright 2003 by Mosby, Inc. All rights reserved. Platelets (Thrombocytes) Smallest blood cells Platelets promote clotting to prevent blood loss Platelets can form a plug to seal small vessels by themselves or start the clotting process Produced in red bone marrow Live about 5 to 9 days

Copyright 2003 by Mosby, Inc. All rights reserved. Plasma A pale yellow liquid that remains when elements are removed from blood Whole blood is 55% plasma Plasma is 90% water and approximately 10% proteins It contains nutrients, electrolytes, oxygen, enzymes, hormones, and wastes Helps fight infection and assists in the clotting (coagulation) of blood

Copyright 2003 by Mosby, Inc. All rights reserved. Blood Typing A person’s blood type is an inherited characteristic of the blood A blood type is determined by the antigens located on the surface of the red blood cell Clumping of incompatible cells blocks blood vessels and may cause death

Copyright 2003 by Mosby, Inc. All rights reserved. Table 11-2 Blood Types

Copyright 2003 by Mosby, Inc. All rights reserved. Lymph and Lymphatic Tissue Two important functions – The process of immunity – Maintaining the body’s fluid balance Lymph is a watery substance formed from fluid that filters into the body tissue or interstitially Lymphatic tissues consist of the tonsils, thymus, spleen, nodes, and the lymph vessels

Copyright 2003 by Mosby, Inc. All rights reserved. Immunity Immune response takes on two forms –As a barrier of the skin, mucous membranes, tears, and the leukocytes –In leukocytes antibodies are formed in response to antigens or foreign materials that enter the body May be a localized or systemic reaction Acquired and/or inherited immunity

Copyright 2003 by Mosby, Inc. All rights reserved. Assessment Techniques Hemoglobin (Hgb) test measures the amount of oxygen-carrying ability of the blood Hematocrit (Hct) measures the volume of erythrocytes in the blood Sedimentation rates measure how long it takes for erythrocytes in the blood to settle to the bottom of a container Reticulocyte studies measure the number of immature red blood cells

Copyright 2003 by Mosby, Inc. All rights reserved. Assessment Techniques (continued) Red blood cell (RBC) counts determine the number of circulating red blood cells in 1 mm 3 of blood Platelet or thrombocyte counts measure the number of platelets in 1 mm 3 of blood to determine clotting ability Aspiration biopsy cytology (ABC) studies examine bone marrow from the iliac crest of the hip

Copyright 2003 by Mosby, Inc. All rights reserved. Issues and Innovations Transfusion – Risks – Autologous transfusions – Platelet donations Interferon – Prevention of viral diseases Monoclonal antibodies – Used in organ transplants, against autoimmune disease, and to diagnose certain diseases