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 tissues
and become macrophages which can live for months
c. Lymphocytes- weeks or months moving from circulation
into the tissues and back again
d. Platelets- replaced about every 10 days (30,000 formed
per 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.
b.
c.
d.
e.
Histiocytes
Macrophages in the lymph nodes
Lungs
Kupffer cells
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.
b.
c.
d.
e.
f.
Vasodilation of local blood vessels
Increased permeability of the capillaries
Clotting of fluids in the interstitial spaces
Migration of granulocytes and monocytes
Swelling of the tissue cells
Chemicals released: histamine, bradykinin,
serotonin, prostaglandins, complement proteins
activated, multiple lymphokines
Inflammation: Role of Neutrophils and Macrophages
• “Walling-Off” Effect of Inflammation- delay the
spread of bacterial or toxins
• Macrophage and Neutrophil Responses
a.
b.
c.
d.
Neutrophil invasion of the inflammed area
Acute increase of neutrophils in blood
Macrophage invasion into area
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/Neutrophil
Responses
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 in
allergic 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