Post on 17-Dec-2015
CHAPTER 3
INFLAMMATION, THE INFLAMMATORY RESPONSE, AND FEVER
CHAPTER 3
INFLAMMATION, THE INFLAMMATORY RESPONSE, AND FEVER
PRE LECTURE QUIZ TRUE/FALSE
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.
T
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F
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PRE LECTURE QUIZ 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.
cardinal
Convection
Fever
hypothalamus
mediators
INFLAMMATION
Inflammation is an automatic response to cell injury that:
Neutralizes harmful agents
Removes dead tissue
Damaged cells release
inflammatory mediators
local responses
vascular stage
cellular stage
systemic (whole-body) responses
white blood cell response
acute-phase response
ACUTE INFLAMMATION
Vascular stage Prostaglandins and leukotrienes affect
blood vessels. Arterioles and venules dilate.
º Increasing blood flow to injured areaº Redness and warmth result
Capillaries become more permeable.º Allowing exudate to escape into the tissuesº Swelling and pain result
QUESTION
What mechanism causes the redness (erythema) associated with the inflammatory process?
a. Prostaglandinsb. Leukotrienesc. Arachidonic acidd. All of the abovee. a and b
ANSWER
e. a and bProstaglandins and leukotrienes cause
vasodilation, which brings more blood to the injured/affected area. The symptoms caused by this vasodilation are redness/erythema and warmth.
SCENARIO:
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?
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
WHITE BLOOD CELLS INVOLVED IN INFLAMMATION
Granulocytes Neutrophils Eosinophils Basophils Mast cells
Monocytes Monocytes Macrophages
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 (CONT.)
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
QUESTION
Which leukocytes participate in the acute inflammatory response?
a. Eosinophils b. Monocytesc. Neutrophils d. All of the abovee. a and c
ANSWER
d. All of the aboveGranulocytes 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.
OTHER INFLAMMATORY MEDIATORS
Other inflammatory mediators travel in the plasma:
Kinins
Coagulation and fibrinolysis proteins
Complement system
C-reactive protein
damaged cells release
inflammatory mediators
local responses
vascular stage
cellular stage
systemic (whole-body) responses
white blood cell response
acute-phase response
ACUTE-PHASE 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
QUESTION
Tell whether the following statement is true or false:
Body temperature is controlled through negative feedback loops.
ANSWER
TrueWhen 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.
SCENARIO:
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?
WHITE BLOOD CELL RESPONSE
Inflammatory mediators cause WBC production
WBC count rises
Immature neutrophils (bands) released into blood
CHRONIC INFLAMMATION
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
SCENARIO: 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.
TISSUE REPAIR
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 tissueº Granulation tissue scar tissue
QUESTION
Tell whether the following statement is true or false:
If you get a paper cut, epithelial tissue will be replaced with connective tissue.
ANSWER
FalseThe 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).