Inflammation and Wound Healing Flashcards
Three lines of defense
- Mechanical barriers and body secretions.
- Phagocytosis, inflammation, and interferons.
- Immune response, very specific.
Phagocytosis
Process by which neutrophils and macrophages randomly engulf and destroy bacteria, cell debris, or foreign matter
Interferons
nonspecific agents that protect uninfected cells against viruses
Immune response
stimulates the production of unique antibodies or sensitized lymphocytes following exposure to specific substance
inflammation
Body’s nonspecific response to tissue injury, resulting in redness, swelling, warmth, pain, and sometimes the loss of function
suffix for inflammation
-itis
Acute inflammation
Occurs rapidly in reaction to cell injury, rids the body of the offending agent, enhances healing, and terminates after a short period. Hours or days.
Prevents the spread of infection with antibodies or other chemicals.
Attempts to wall off, destroy, and digest bacteria and dead or foreign tissue.
After insult is contained, repair can begin.
Chronic inflammation
May develop following an acute episode of inflammation when the cause is not completely eradicated.
Examples of chronic inflammation
Smoking, certain bacteria, or long-term abnormal immune response.
Granulocytes
Neutrophils
Basophils
Eosinophils
Agranulocytes
Lymphocytes
Monocytes
Arrive first at the site of cell injury, are the most numerous leukocyte, are part of the innate immune system.
Neutrophils
Active in allergic responses ,releasing their stores of inflammatory chemicals including histamine, serotonin, and leukotrienes. Contain heparin. Fight parasitic infections
Basophils
Active in larger parasitic infections, allergy responses, and some cancers
Eosinophils
B (humoral), T (cell mediated), and Natural Killer (NK) Cells
Identify and destroy foreign invaders
Found in lymph and blood
NK cells defend against tumors and viruses
Lymphocytes
Largest WBC; differentiates into macrophages that clean up cellular debris in the inflammatory process
Monocytes
Cytokines
short-lived proteins that are released by one cell as intracellular messengers
inflammatory mediators
send out signals, enabling the blood vessels to dilate and become more permeable, allowing fluids, WBC to enter
three stages of acute inflammation
- vascular permeability
- cellular chemotaxis
- systemic responses
WBC line up along endothelium when arriving at site of injury
margination
Three outcomes of acute inflammation
Complete resolution
Healing by connective tissue
Chronic, persistent inflammation that does not recede
Complete resolution of acute inflammation
normalization of vascular permeability
deactivation of chemical mediators
elimination of cellular debris and edema
apoptosis of WBC
Healing by connective tissue acute inflammation
In tissues that cannot regenerate cells or exudates and cellular debris cannot be adequately cleared.
Cellular debris and exudates are instead reabsorbed and fibrous scar tissue replaced damaged cells.
Characteristics of chronic inflammation
less swelling, more lymphocytes, macrophages, fibroblasts, more collagen