Unit Six: Blood Cells, Immunity, and Blood

Coagulation

Chapter 33: Resistance of the Body to Infection. I. Leukocytes, Granulocytes, the

Monocyte-Macrophage System, and Inflammation

Guyton and Hall, Textbook of Medical Physiology, 12th edition

Leukocytes (White Blood Cells)

• General Characteristics

a. Types: neutrophils, basophils, eosinophils, monocytes,lymphocytes (plasma cells)

b. Concentrations in the blood

White Blood Cell % in Whole Blood

Polymorphonuclear Neutrophils

62.0%

Polymorphonuclear Eosinophils 2.3%

Polymorphonuclear Basophils 0.4%

Monocytes 5.3%

Lymphocytes 30.0%

Leukocytes (White Blood Cells)

• Genesis of WBCs

Fig. 33.1 Genesis of WBCs

Leukocytes (White Blood Cells)

• Life Span of WBCs

a. Granulocytes- 4-8 hrs in the blood and 4-5 days in tissues

b. Monocytes- 10-20 hrs in the blood, move into tissuesand become macrophages which can live for months

c. Lymphocytes- weeks or months moving from circulationinto the tissues and back again

d. Platelets- replaced about every 10 days (30,000 formedper day per microliter of blood

Neutrophils and Macrophages Defend Against Infections

• WBCs Enter the Tissue Spaces by Diapedsis

• WBCs Move Through the Tissues by Ameboid Motion

• WBCs Are Attracted to Inflamed Tissue by Chemotaxis

Neutrophils and Macrophages (cont.)

Fig. 33.2

Neutrophils and Macrophages (cont.)

• Phagocytosis

a. Process

b. Neutrophils

c. Macrophages

d. Phagolysosomes

e. Bactericidal properties

Monocyte-Macrophage Cells System

• Reticuloendothelial System (RES)

a. Histiocytesb. Macrophages in the lymph nodesc. Lungsd. Kupffer cellse. Spleen and Bone Marrow

Fig. 33.3 Functional diagram of a lymph node

Fig. 33.4 Kupffer cells lining the liver sinusoids Fig. 33.5 Functional structures of the spleen

Inflammation: Role of Neutrophils and Macrophages

• Inflammation

a. Vasodilation of local blood vesselsb. Increased permeability of the capillariesc. Clotting of fluids in the interstitial spacesd. Migration of granulocytes and monocytese. Swelling of the tissue cellsf. Chemicals released: histamine, bradykinin,

serotonin, prostaglandins, complement proteinsactivated, multiple lymphokines

Inflammation: Role of Neutrophils and Macrophages

• “Walling-Off” Effect of Inflammation- delay thespread of bacterial or toxins

• Macrophage and Neutrophil Responses

a. Neutrophil invasion of the inflammed areab. Acute increase of neutrophils in bloodc. Macrophage invasion into aread. Increased production of granulocytes and monocytes

by the bone marrow

Fig. 33.6 Migration of neutrophils from the blood into the inflamed tissue

Inflammation (cont.)

• Feedback Control of the Macrophage/NeutrophilResponses

G-CSF: Granulocyte Colony Stimulating Factor

GM-CSF: Granulocyte-Monocyte Colony Stimulating Factor

IL-1: Inteleukin 1

M-CSF: Monocyte Colony Stimulating Factor

TNF: Tumor Necrosis Factor

Fig. 33.7

Eosinophils

• Eosinophils

a. Weakly phagocytic

b. Prominent in parasitic infections

c. Collect in areas where allergic reactions occur

Basophils

• Basophils

a. Similar to mast cells

b. Release heparin in the blood

c. Release histamine, bradykinin, and serotonin

d. IgE binds to basophil-release of histamine inallergic reactions

Leukopenia and Leukemia

• Leukopenia- bone marrow produces few wbcs

a. Caused by irradiation (x-rays or gamma rays)

b. Exposure to drugs and chemicals

• Leukemia- uncontrolled production of wbcs

a. Types

b. Effects on the body