Download CIRCULATORY SYSTEM

CHAPTER 11
CIRCULATORY SYSTEM
Copyright 2003 by Mosby, Inc. All
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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
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Blood
• Body contains approximately 4 to 5 liters of
blood, making up about 8% of the body’s
weight
• Functions include:
–
–
–
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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
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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
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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
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Five Types of White Blood
Cells
•
•
•
•
•
Neutrophils
Basophils
Eosinophils
Lymphocytes
Monocytes
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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
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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
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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
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Table 11-2 Blood Types
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
Copyright 2003 by Mosby, Inc. All
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