chapter 14 blood functions blood cells red blood cells white blood cells platelets (cell fragments)...

Chapter 14Blood

Functions•

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Blood Cells•

• red blood cells• white blood cells• platelets (cell fragments)

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Blood Volume

• varies with• • changes in fluid concentration• changes in electrolyte concentration•

• about % of weight• about liters

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Blood Composition

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Origin of Blood Cells

14-5

Red Blood Cells

• • biconcave• one-third hemoglobin•

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14-6Red Blood.mov

Red Blood Cell Count

• # of RBCs in a cubic millimeter of blood

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• 4,200,000 – 5,400,000 in adult females

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• reflects blood’s oxygen carrying capacity

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Red Blood Cell Production

• low blood oxygen causes kidneys and liver to release erythropoietin which stimulates RBC production

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14-8

Life Cycle of Red Blood Cell

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• macrophages in spleen and liver destroy worn out RBCs

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• bilirubin and biliverdin excreted in bile

14-9

0025.exe

Types of Anemia

• aplastic anemia• • toxic chemicals• radiation

• hemolytic anemia• • toxic chemicals

• iron deficiency anemia• hemoglobin deficient•

• pernicious anemia• • inability to absorb B12

• sickle cell anemia• • defective gene

• thalassemia• hemoglobin deficient• • defective gene

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Hemolytic Anemia

Normal RBCs

RBCs of person with hemolytic anemia

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White Blood Cells

• leukocytes•

• granulocytes• neutrophils• eosinophils• basophils

• agranulocytes• lymphocytes• monocytes

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Neutrophils

• • first to arrive at infections• phagocytic• of leukocyte• elevated in bacterial infections

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Basophils

• release histamine• release heparin• less than % of leukocytes

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Eosinophils

• • moderate allergic reactions•1% - 3% of leukocytes•

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Monocytes

• • kidney-shaped or oval nuclei• leave bloodstream to become macrophages• of leukocytes•

14-16

Lymphocytes

• size of RBC• large spherical nuclei• T cells• B cells• important in immunity• produce antibodies• of leukocytes• decreased T Cells in AIDS

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White Blood Cell Counts

• number of WBCs per cubic mm• per cubic mm

• leukopenia • • typhoid fever, flu, measles, mumps, chicken pox, AIDS

• leukocytosis • • acute infections, vigorous exercise, great loss of body fluids

• differential WBC count• lists percentages of types of leukocytes• may change in particular diseases 14-19

Blood Platelets

• thrombocytes• • 130,000 – 360,000 per cubic mm•

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Blood Plasma

• straw colored• • % of blood

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Plasma Proteins

Albumins• most numerous plasma proteins• originate in liver• help maintain osmotic pressure of blood

Fibrinogen• originate in liver• plays key role in blood coagulation

Alpha and Beta Globulins• originate in liver• transport lipids and fat-soluble vitamins

Gamma Globulins• originate in lymphatic tissues• constitute the antibodies of immunity

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Gases and Nutrients

Gases• oxygen• carbon dioxide• nitrogen

Nutrients • amino acids• simple sugars• nucleotides• lipids• lipoproteins

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Plasma Lipoproteins

Chylomicrons•transport dietary fats to muscles and adipose cells

HDLs• relatively high concentration of proteins• relatively low concentration of lipids• transport remnants of chylomicrons to liver•

LDLs• relatively high concentration of cholesterol• formed from VLDLs• deliver cholesterol to various cells•

VLDLs•produced in the liver• transport triglycerides from liver to adipose cells

14-24

High Cholesterol

Plasma Electrolytes

• sodium• potassium• calcium• magnesium• chloride• bicarbonate• phosphate• sulfate• sodium and potassium most abundant

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Hemostasis

• stoppage of bleeding

Blood Vessel Spasm•

• smooth muscle in vessel contracts

Platelet Plug Formation

• triggered by exposure of platelets to collagen•

Blood Coagulation•

• blood clot forms

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Platelet Plug Formation

14-28

Blood Clots

• After forming, blood clot retracts and pulls the edges of a broken vessel together

• Platelet-derived growth factor stimulates smooth muscle cells and fibroblasts to repair damaged blood vessels

• Plasmin digests blood clots

• thrombus – • embolus –

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Prevention of Coagulation

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• As a clot forms, fibrin absorbs thrombin and prevents the reaction from spreading

• Some cells secrete heparin

14-32

ABO Blood Group

14-33Blood Type.mov

Preferred and Permissible Blood Types for Transfusion

14-35

Clinical Application

Leukemia

Myeloid Leukemia• bone marrow produces too many immature granulocytes• leukemic cells crowd out other blood cells• anemia• bleeding• susceptible to infections

Lymphoid Leukemia• lymphocytes are cancerous• symptoms similar to myeloid leukemia

Treatments• blood transfusions• marrow transplants• anti-cancer drugs• stem cell transplants

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