Chapter 6

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Chapter 6

Cardiovascular System: Blood

• Who is this?

• Harry

• What is he doing?

• Donating whole blood for a friend who was in an accident.

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Outline

• Blood: An Overview• Function and Composition of Blood• Red Blood Cells and Transport of Oxygen• White Blood Cells and Defense Against

Disease• Platelets and Blood Clotting• Blood Typing and Transfusions• Homeostasis

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•Difference between giving plasma (plasmaphoresis) and giving whole blood?

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Functions of Blood

• Transport of oxygen, hormones, and waste.• (Blood is the primary transport medium.)• Defense against pathogens (disease,

producer).• (Blood defends the body against invasion by

pathogens in several ways.)• Regulation of body temperature / prevent

blood loss• (Blood has regulatory functions.)

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Composition of Blood

• Blood is divided into two layers.– Formed Elements.

Red Blood Cells.White Blood Cells.Platelets.

– Plasma.

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Plasma

• Water makes up about 92% of plasma, while the remaining 8% consists of various salts and organic molecules.

• Three major plasma proteins help to maintain homeostasis.– Albumins (osmotic pressure).– Globulins (defense).– Fibrinogen (clotting).

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Red Blood Cells and Transport of Oxygen• Red blood cells (erythrocytes) contain hemoglobin that

allows oxygen transport and have no nucleus.– Aliases: Red cells, RBC, RC.– All blood cells are formed from stem cells in the red

bone marrow.– Engulfed by macrophages (big, eater) in the liver

and spleen after about 120 days. Releases hemoglobin. (Text figure)

~ 200 million / RBC! Insufficient number of red blood cells or

hemoglobin leads to anemia. Hemolysis (blood, to burst) is rupturing of blood

cells. Carbon monoxide (CO)?

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White Blood Cells and Defense Against Disease

• White Blood Cells (leukocytes) have a nucleus and lack hemoglobin.– Aliases: white cell, WBC, WC.– Fight infection and help maintain homeostasis.– Derived from stem cells in red bone marrow:

colony-stimulating factors (CSFs)– SCID ?– Leukemia ? – Infectious mononucleosis (EBV) ?– Found in blood, tissue fluid, and lymph.

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Types of White Blood Cells

• Granular Leukocytes.– Neutrophils (phagocytosis – eater, cell).– Eosinophils.– Basophils.

• Agranular Leukocytes.– Monocytes macrophages (big eaters).– Lymphocytes – two types:

B cells antibodies (Ab) T cells (T helper cell – AIDS).

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Platelets and Blood Clotting• Platelets (thrombocytes) result from fragmentation of

megakaryocytes.– Platelets clump at the site of a puncture in the skin

and usually seal the break. Hemophilia (blood, loving)?

King’s disease, free bleeders. Thromo/cyto/penia, Thromboembolism ? Coagulation (clotting).

At least twelve factors participate in the formulation of a blood clot.

Most common is “factor 8”. Ca++ is critical to the process. Extrinsic and intrinsic processes. . . .

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Health Focus

What to Know When Giving Blood

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Blood Typing and Transfusions

• Video clip (#40).• In the ABO system, the presence or

absence of type A and type B antigens (Ag) on red blood cells determines a person’s blood type.– Within the plasma are antibodies to the

antigens that are not present on the person’s red blood cells.

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Rh Blood Groups

• Another important antigen is the Rh factor.– Eighty-five percent of US population have

Rh antigen on red blood cells and are Rh+.Rh- individuals (15%) normally do not

have antibodies to the Rh factor, but may make them when exposed.

Hemolytic disease of the newborn (HDN) may exist in newborns when mother is Rh- and father is Rh+.

Also called Fetalis erythroblastosis.

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Hemolytic Disease

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Hemolytic Disease

• Problems in subsequent pregnancies can be prevented by giving the mother a drug (RhoGam) at the time of the birth of each Rh+ child.

• It is anti-Rh antibodies which destroy any of the child’s blood cells that the mother’s body is exposed to before she has a chance to form antibodies against the Rh factor. . . .

• so, it is as if she had never had an Rh+ child before making it safe for subsequent pregnancies.

HISTORICAL FOCUS

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Making Blood Transfusion Possible: Karl Landsteiner

(1868-1943)

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Homeostasis

• Homeostasis is possible only if the cardiovascular system delivers oxygen and nutrients to, and takes metabolic wastes away from, the tissue fluid surrounding cells.– Cardiovascular system must work with

other systems to maintain homeostasis such as ?????

– Don’t forget to review the “Human Systems Work Together”

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Review• Blood: An Overview• Function and Composition of Blood• Red Blood Cells and Transport of Oxygen• White Blood Cells and Defense Against

Disease• Platelets and Blood Clotting• Blood Typing and Transfusions• Homeostasis

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Blood Typing

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