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Chapter 3 Inflammation, the Inflammatory Response, and Fever. Acute inflammation is the immediate and early response to an injurious agent and occurs in two phases; the vascular phase and the cellular phase.
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Acute inflammation is the immediate and early response to an injurious agent and occurs in two phases; the vascular phase and the cellular phase. Chronic inflammation is self-perpetuating and may last for weeks, months, or even years. Erythrocytes play a central role in the physiology of inflammation. Vasoconstriction occurs during the vascular stage of inflammation. Fever is a pathologic response to bacterial and viral infection with and has no positive outcome on illness. Pre lecture quiz true/false T T F F F
The ______________ signs of inflammation are known as redness, swelling, heat, pain, and loss of function. Histamine, serotonin, cytokines, bradykinin, arachidonic acid, and platelet-activating factor are _____________ of inflammation. Body temperature is regulated by the thermoregulatory center in the ________________. ____________, or pyrexia, represents an increase in body temperature due to resetting of the hypothalamic thermoregulatory set point as the result of endogenous pyrogens released from host macrophages or endothelial cells. _____________ refers to heat transfer through the circulation of air currents. Pre lecture Quiz cardinal Convection Fever hypothalamus mediators
Inflammation is an automatic response to cell injury that: • Neutralizes harmful agents • Removes dead tissue Inflammation
Inflammation • Damaged cells release inflammatory mediators. • These compounds stimulate inflammation.
Damaged cells release inflammatory mediators local systemic (whole- responses body) responses vascular cellular white blood acute-phase stage stage cell response response
Vascular stage • Prostaglandins and leukotrienes affect blood vessels. • Arterioles and venules dilate. • Increasing blood flow to injured area • Redness and warmth result • Capillaries become more permeable. • Allowing exudate to escape into the tissues • Swelling and pain result Acute Inflammation
What mechanism causes the redness (erythema) associated with the inflammatory process? • Prostaglandins • Leukotrienes • Arachidonic acid • All of the above • a and b Question
a and b Prostaglandins and leukotrienes cause vasodilation, which brings more blood to the injured/affected area. The symptoms caused by this vasodilation are redness/erythema and warmth. Answer
Serous Hemorrhagic Fibrinous Membranous Purulent Kinds of Exudate
A woman has peritonitis … • She has a distended abdomen, low blood pressure, and fluid in her abdominal cavity. • After surgery, she is told to report any GI distress as it may indicate fibrous adhesions. Question: • What kinds of exudate are involved? What useful purposes do they serve? What complications may they cause? Scenario:
Cellular Stage • White blood cells enter the injured tissue: • Destroying infective organisms • Removing damaged cells • Releasing more inflammatory mediators to control further inflammation and healing
Granulocytes • Neutrophils • Eosinophils • Basophils • Mast cells • Monocytes • Monocytes Macrophages White Blood Cells Involved in Inflammation
Leukocytes • Leukocytes enter the injured area • Leukocytes express adhesive proteins • Attach to the blood vessel lining • Squeeze between the cells • Follow the inflammatory mediators to the injured area
Leukocytes release many inflammatory mediators at the injured area: • Histamine and serotonin • Platelet-activating factor • Cytokines • Colony-stimulating factors • Interleukins • Interferons • Tumor necrosis factor • Nitric oxide Leukocytes (cont.)
Which leukocytes participate in the acute inflammatory response? • Eosinophils • Monocytes • Neutrophils • All of the above • a and c Question
All of the above Granulocytes and monocytes play a role in the acute phase of the immune response. Eosinophils and neutrophils are granulocytes, so all of the leukocytes listed participate. Answer
Other inflammatory mediators travel in the plasma: • Kinins • Coagulation and fibrinolysis proteins • Complement system • C-reactive protein Other Inflammatory Mediators
damaged cells release inflammatory mediators local systemic (whole- responses body) responses vascular cellular white blood acute-phase stage stage cell response response
Leukocytes release interleukins and tumor necrosis factor • Affect thermoregulatory center fever • Affect central nervous system lethargy • Skeletal muscle breakdown • Liver makes fibrinogen and C-reactive protein • Facilitate clotting • Bind to pathogens • Moderate inflammatory responses Acute-Phase Response
Tell whether the following statement is true or false: Body temperature is controlled through negative feedback loops. Question
True When the body senses a change out of the norm (as illustrated in the previous slides), it activates mechanisms that oppose that change (vasodilation and sweating with increased temperatures; vasoconstriction and shivering with decreased temperatures). This is known as negative feedback. Positive feedback, on the other hand, senses a change but activates a mechanism that exaggerates the change. Answer
Mr. X says he has “chills and fever”… • His daughter wants you to explain how he could have both at the same time and from the same disease Question: • Should she be keeping him warmer or helping him cool off? Scenario:
Inflammatory mediators cause WBC production WBC count rises Immature neutrophils (bands) released into blood White Blood Cell Response
Macrophages accumulate in the damaged area and keep releasing inflammatory mediators. • Nonspecific chronic inflammation • Fibroblasts proliferate • Scar tissue forms • Granulomatous inflammation • Macrophages mass together around foreign bodies • Connective tissue surrounds and isolates the mass Chronic Inflammation
A man had tuberculosis (TB) long ago, and when he first had the disease, he had a fever, productive cough, and bloody sputum. • Later, he had trouble breathing and the doctor said his lungs were “consolidated” with fibrous proteins. • He recovered and his fever went down; he thought he was cured. • Three years later, an x-ray showed nodules in his lungs and he was told they contained the TB bacteria. Question: • Identify inflammatory events in his case. Scenario:
Growth factors stimulate local cells to divide. • Tissue organization is controlled by the extracellular matrix. • New cells are laid down on the extracellular matrix. • Tissue regeneration: injured tissue is replaced by the same kind of cells • Fibrous tissue repair: injured tissue is replaced by connective tissue • Granulation tissue scar tissue Tissue Repair
Tell whether the following statement is true or false: If you get a paper cut, epithelial tissue will be replaced with connective tissue. Question
False The surface epithelial cells of the skin are most likely to be damaged in this instance. Surface epithelial tissue has the ability to regenerate, replacing the damaged tissue with the same type (epithelial). Answer
Inflammatory phase Proliferative phase Remodeling phase Wound Healing