CHAPTER 11CIRCULATORY SYSTEM : Copyright 2003 by Mosby, Inc. All rights reserved. CHAPTER 11CIRCULATORY SYSTEM
Structure and Function : 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
Blood : 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
Red Blood Cells (Erythrocytes) : 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
White Blood Cells (Leukocytes) : 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
Five Types of White Blood Cells : Copyright 2003 by Mosby, Inc. All rights reserved. Five Types of White Blood Cells Neutrophils
Basophils
Eosinophils
Lymphocytes
Monocytes
Platelets (Thrombocytes) : 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
Plasma : 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
Blood Typing : 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
Table 11-2 Blood Types : Copyright 2003 by Mosby, Inc. All rights reserved. Table 11-2 Blood Types
Lymph and Lymphatic Tissue : 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
Immunity : 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
Assessment Techniques : 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
Assessment Techniques (continued) : 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 mm3 of blood
Platelet or thrombocyte counts measure the number of platelets in 1 mm3 of blood to determine clotting ability
Aspiration biopsy cytology (ABC) studies examine bone marrow from the iliac crest of the hip
Disorders of the Circulatory System : Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Circulatory System Acquired immunodeficiency syndrome
Dysfunction of the immune system caused by a virus
Allergy
Hypersensitive response by the immune system to an outside substance
Anemia
The blood has an inadequate amount of hemoglobin, red blood cells, or both
Disorders of the Circulatory System (continued) : Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Circulatory System (continued) Autoimmune
Conditions in which the immune system of the body turns against itself
Elephantiasis
A massive accumulation of lymphatic fluid in body tissues, causing an abnormally large growth of tissue or hypertrophy
Erythroblastosis fetalis
A condition in an unborn baby in which the mother forms antibodies against the antigens in the baby’s blood
Disorders of the Circulatory System (continued) : Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Circulatory System (continued) Hemophilia
A rare sex-linked genetic blood disease in which the blood is missing a clotting factor
Hepatitis
A viral infection of the blood
Hodgkin’s disease
A malignant cancer of the lymph system
Disorders of the Circulatory System (continued) : Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Circulatory System (continued) Leukemia
Also called blood cancer, is an abnormal malignant increase in the number and longevity of white blood cells
Lymphosarcoma
Is a group of malignant cancers of lymph tissues other than Hodgkin's disease
Polycythemia
An abnormal increase in the number of blood cells, making the blood thicker and slower flowing
Disorders of the Circulatory System (continued) : Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Circulatory System (continued) Septicemia
Called blood poisoning, is an infection that occurs when pathogens enter the blood
Sickle cell anemia
A genetic condition that results in malformed red blood cells
Splenomegaly
An enlargement of the spleen caused by an acute infection such as mononucleosis or anemia
Disorders of the Circulatory System (continued) : Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Circulatory System (continued) Thalassemia
One of the most common genetic blood disorders
Thrombocytopenia
A decrease in the number of platelets in the blood
Thrombosis
A condition in which a blood clot, called a thrombus, forms in the blood vessels
Issues and Innovations : 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