2. 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
3. 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
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4. 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
5. 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
6. Five Types of White Blood
Cells
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Neutrophils
Basophils
Eosinophils
Lymphocytes
Monocytes
7. 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
8. 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
9. 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
11. 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
12. 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
13. 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
14. 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
15. 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
16. 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
17. 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
18. 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
19. 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
20. 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
21. 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
