Chapter 14Blood

Functions• transports vital substances• maintains stability of interstitial fluid• distributes heat

Blood Cells• form mostly in red bone marrow• red blood cells• white blood cells• platelets (cell fragments)

14-2

Blood Volume

• varies with• body size• changes in fluid concentration• changes in electrolyte concentration• amount of adipose tissue

• about 8% of body weight• about 5 liters

14-3

Blood Composition

14-4

Origin of Blood Cells

14-5

Red Blood Cells

• erythrocytes• biconcave• one-third hemoglobin

• oxyhemoglobin• deoxyhemoglobin

• can readily squeeze through capillaries• lack nuclei and mitochondria

14-6

Red Blood Cell Count

• number of RBCs in a cubic millimeter of blood

• 4,600,000 – 6,200,000 in males

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

• 4,500,000 – 5,100,000 in children

• reflects blood’s oxygen carrying capacity

14-7

Red Blood Cell Production

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

• vitamin B12, folic acid and iron necessary

14-8

Life Cycle of Red Blood Cell

• circulate for about 120 days

• macrophages in spleen and liver destroy worn out RBCs

• hemoglobin is broken down into heme and globin

• iron return to red bone marrow

• bilirubin and biliverdin excreted in bile

14-9

White Blood Cells

• leukocytes• protect against disease• interleukins and colony-stimulating factors stimulate development

• granulocytes• neutrophils• eosinophils• basophils

• agranulocytes• lymphocytes• monocytes

14-12

Neutrophils

• light blue granules in acid-base stain• lobed nucleus• other names

• segs• polymorphonuclear leukocyte• bands (young neutrophils)

• first to arrive at infections• phagocytic• 54% - 62% of leukocyte• elevated in bacterial infections

14-13

Basophils

• deep blue granules is basic stain• release histamine• release heparin• less than 1% of leukocytes

14-14

Eosinophils

• deep red granules in acid stain• bilobed nucleus• moderate allergic reactions• defend against parasitic worm infestations• 1% - 3% of leukocytes• elevated in worm infestations and allergic reactions

14-15

Monocytes

• largest blood cell• kidney-shaped or oval nuclei• leave bloodstream to become macrophages• 3% - 9% of leukocytes• elevated in typhoid fever, malaria, tuberculosis

14-16

Lymphocytes

• about the size of RBC• large spherical nuclei• thin rims of cytoplasm• T cells• B cells• important in immunity• produce antibodies• 25% - 33% of leukocytes• decreased T Cells in AIDS

14-17

Diapadesis

• leukocytes squeeze through capillary walls to enter tissue space outside the blood vessel

14-18

White Blood Cell Counts

• number of WBCs per cubic millimeter of blood• 5,000 – 10,000 per cubic millimeter of blood

• leukopenia • low WBC count• typhoid fever, flu, measles, mumps, chicken pox, AIDS

• leukocytosis • high WBC count• 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• cell fragments of megakaryocytes• 130,000 – 360,000 per cubic millimeter of blood• helps control blood loss from broken vessels

14-20

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 – abnormal blood clot• embolus – blood clot moving through blood

14-31

Blood Plasma

• straw colored• liquid portion of blood• 55% of blood

14-21

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

14-22

Gases and Nutrients

Gases• oxygen• carbon dioxide• nitrogen

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

14-23

ABO Blood Group

14-33

Agglutination

14-34

Preferred and Permissible Blood Types for Transfusion

14-35