Chapter 6 Inflammation and Wound Healing Flashcards
Inflammation
a protective, coordinated response of the body to an injurious agent
The major aims of inflammation
wall-off the area of injury, prevent spread of the injurious agent, and bring the body’s defenses to the region under attack.
Acute inflammation
rapidly in reaction to cell injury, rids the body of the offending agent, enhances healing, and terminates after a short period, either hours or a few days
Chronic inflammation
when the inflammatory reaction persists, inhibits healing, and causes continual cellular damage and organ dysfunction. Continues for days (ulcers, TB, RA, SLE, MS, asthma)
Acute Inflammatory Reaction Three Main Stages
Stage 1: vascular permeability
Stage 2: cellular chemotaxis
Stage 3: systemic responses
Vascular Permeability
histamine and bradykinin enable the blood vessels to dilate and become more permeable.
Vasodilation of the arterioles is followed by
enhanced capillary permeability
Cardinal Signs of Inflammation
Rubor (redness)
Tumor (swelling)
Calor (heat)
Dolor (pain)
Loss of function
Macrophages
surround and consume the foreign material in a process called phagocytosis
fluid that leaves the capillaries
protein-rich filtrate of blood that contains WBCs called macrophages
Purulent exudate
rich in protein
Transudate
little protein and is mainly a watery filtrate
margination
WBCs arrive at the site of inflammation line up along the endothelium in the area of inflammation
cytokines
inflammatory mediators released by WBCs
-amplify or deactivate inflammation
acute phase proteins
proteins influence the inflammatory process by stimulating, modulating, and deactivating the reaction.
C-reactive protein (CRP)
a substance produced by the liver that increases in the presence of inflammation in the body
Erythrocyte sedimentation rate (ESR)
When your blood is placed in a tall, thin tube, red blood cells (erythrocytes) gradually settle to the bottom. Inflammation can cause the cells to clump.
-The farther the red blood cells have descended, the greater the inflammatory response of your immune system.
Neutrophils
First responders
-referred to as polymorphonuclear leukocytes (PMNs
-immature form, they are called bands or stabs.
-multisegmented nuclei
Lymphocytes
Chronic infection or leukemia
Eosinophils
Allergic reaction
Basophils
Decrease is acute allergic reaction
Monocytes (macrophages)
Inflammatory disease/infection
shift to the left
high number of bands are present, indicating an increase in newly formed neutrophils (immature wbc’s)
-elevated WBC count (acute inflammatory process)
granulocytes
-Neutrophils, basophils, and eosinophils
-contain important enzymes and inflammatory mediators to fight infection (phagocytosis).
WBC differential
used in the diagnosis of infection and inflammation
Systemic Responses
Fever
Pain
General malaise (a general feeling of poor health)
Lymphadenopathy (swollen lymph nodes)
Anorexia
Sleepiness
Lethargy
Anemia
Weight loss
Inflammatory Mediators Released From WBCs
-Prostaglandins
-Leukotrienes
-Tumor necrosis factor (TNF-alpha)
-Interleukins (Ils)
Prostaglandins
Vasodilation, inhibit platelet aggregation, bronchodilation, bronchoconstriction, GI tract contraction, GI tract relaxation, decrease gastric acid secretion, increase mucus secretion
Leukotrienes
-Metabolites of arachidonic acid
-Contraction of bronchial smooth muscles (triggering asthma attacks), stimulation of vascular permeability, and attraction and activation of leukocytes.
Tumor necrosis factor (TNF-alpha)
-Stimulates phagocytosis so it promotes the inflammatory response
-An endogenous pyrogen, able to induce fever, apoptotic cell death, inflammation, inhibit tumorigenesis (so not all cells turn into cancer cells), and viral replication
Interleukins (Ils)
important in stimulating immune responses, such as inflammation
Cyclooxygenase (COX-1)
responsible for transforming arachidonic acid into eicosanoids (inflammation, blood pressure regulation, and blood clotting) and is found throughout your body, normal body function such as stomach mucous production, regulation of gastric acid, and kidney water excretion.
cyclooxygenase (COX-2)
released by inflammatory cells and transforms arachidonic acid into the eicosanoids responsible for causing, pain, inflammation, including fever promotion
Nonsteroidal anti-inflammatory drugs, or NSAIDs, such as aspirin and ibuprofen
counter inflammation by inhibiting the action of cyclooxygenase
-potentially causes an increase in stomach acid. This is because the first type of cyclooxygenase stops the secretion of stomach acid
pyrogens
substances that cause fever
-activate prostaglandins to reset the hypothalamic temperature-regulating center (higher)
-
antipyretic agent
drug that brings down fever.
It is recommended to keep fever below
102°F
Histamine
inflammatory mediator released from basophils, platelets, and mast cells.
Histamines are stimulated by
Physical injury, immune reactions, cytokines, and other inflammatory mediators
consequences of histamine released in the upper respiratory tract
Sneezing, rhinorrhea (runny nose), eye tearing, sinus inflammation, and pharyngeal irritation
Lymphadenopathy, or lymphadenitis
enlargement of lymph nodes caused by inflammatory processes
Acute Inflammation Will Result in
-Complete resolution
-Healing by connective tissue
-Chronic, persistent inflammation that does not recede
Chronic inflammation often causes a
granuloma
Granuloma
area where macrophages have aggregated and are transformed into epithelial-like cells. The epithelioid cells are surrounded by lymphocytes, fibroblasts, and connective tissue
Tuberculosis (TB) is the
prototypical granulomatous chronic inflammatory disease
Wound Healing Is Divided Into Three Phases
-Inflammation
-Proliferation, granulation tissue formation, and epithelialization
-Wound contraction and remodeling
Skin Wounds Heal by One of Three Processes
-Primary intention
-Secondary intention
-Tertiary intention
Primary Intention
-A clean laceration that requires simple re-epithelialization when edges are approximated
Example: surgical laceration
Secondary Intention
-A wound with a large gap in tissue; some of the tissue has been gouged out.
Example: decubitus ulcer
Tertiary Intention
A wound with a large gap of missing tissue that has been contaminated and needs a drainage tube while healing
The healed wound builds to a maximal tensile strength of ____ to ____ after ________
70% to 80% after 3 months.
Factors Involved in Wound Healing
Nutrition
Oxygenation
Circulation
Immune strength
Diabetes; weakens healing
Use of corticosteroids; diminishes healing
Use of immunosuppressant agents
Contamination
Surgically inserted devices
Obesity
Age
Keloid
hyperplasia of scar tissue
Contractures
inflexible shrinkage of wound tissue that pulls the edges toward the center of the wound
Dehiscence
opening of a wound’s suture line
Evisceration
opening of wound with extrusion of tissue and organs
Stricture
an abnormal narrowing of a tubular body passage from the formation of scar tissue
Fistula
abnormal connection between two epithelium-lined organs or vessels
