Systemic Disease Flashcards
(533 cards)
Inflammation
Defense response that elimates the products of cellular injuries. Inflammation plays a role in the healing of injured cells bi diluting or destroying the agent responsible for injury.
Acute inflammation
Occurs in 1-2 minutes post injury. Leukocytes help clear up the injury site by invading bacteria and degrade necrotic byproducts of the damage. Acute inflammation is deterministic-it happens the same way every tine
What are the three major types of acute inflammation
- Vascular size changes (dilation) to facilitate increased blood flow
- Structural changes in the microvasculature (increased permeability) facilitate the arrival of plasma proteins and leukocytes from the circulation
- Immigration of neutrophils (PMNs) from circulation to the site of injury
What does acute inflammation generate
RUBOR (redness)
CALOR (heat)
DOLOR (pain)
TUMOR (swelling)
Also the presence of WBCs
Possible outcomes of acute inflammation
Complete resolution
Scarring of fibrosis
Abscess formation
Progression to chronic inflammation
Chronic inflammation
Last weeks to years. Active inflammation, tissue injury, and healing progress at the same rate.
Chronic inflammation is characterized by
- Infiltration with mononuclear cells (macrophages, lymphocytes, and plasma cells)
- Tissue destruction
- Repair involving new vessel proliferation (neovascularization) and fibrosis
Chronic inflammation will arise from
- Persistent infections (H. Pylori)
- Prolonged exposure to potential toxic agents (asbestos)
- AI disease (RA)
Presentation of chronic inflammation
Not all chronic inflammations are identical. In fact the body adjusts the response according to the type of injury. One type of chronic inflammation is granulomatous inflammation
Granulomatous inflammation
Is marked by collections of large, activated macrophages with a squamous cell-like appearance
Examples of granulomatous inflammation
Bacterial: TB, leprosy, syphilis
Fungal: histoplasmosis, blastomycosis
FB: suture, vascular graft
Unknown: sarcoidosis
Local factors that affect wound healing
Prolonged healing: local infection, decreased blood supply, and the inabilialty to form clots
Systemic factors that can prolong healing
Diabetes, immunocompromised states, decreased peripheral blood flow, systemic infection, malnutrition, and increases glucocorticoid production (stress)
Reversible cellular injury
Process is marked by decrease in blood supply to a cell and a corresponding decrease in oxygen supply (hypoxia)
Lack of oxygen to a cell will cause
- increase in glycolysis and anaerobic respiration-the lack of oxygen leads to increases lactic acid concentration and a decrease in tissue pH
- a decrease ATP production, which disrupts the Na and K gradient across the cell; this causes accumulation of intracellular Na and subsequent cellular edema
If oxygen is restored to a cell during injury
ATP increases, the Na-K pump is restored, and anaerobic respiration ceases. Persistent ischemia will lead to irreversible cell injury
Irreversible cell injury
- Insuffient ATP resutls in Na accumulation and the cell, in turn, becomes edematous, which disrupts the cell membrane. This causes crucial cellular components needed for the reconstruction of ATP to leak out, and thereby further facilitates the depletion of high energy phosphates
- lack of oxygen will ultimately increase ischemia, causing irreversible tissue necrosis.
The events leading to irreversible tissue necrosis from cell ischemia
- progressive loss of membrane phospholipids
- cytoskeleton abnormalities
- toxic oxygen radicals, which damage the cell membrane and other cell components
- lipid breakdown products, which accumulate in ischemic cells and result in phospholipid degradation
Necrosis is a result of
Irreversible cell death
The death of one or more cells as a result of irreversible damage
Necrosis
What are the two processes that occur with necrosis
- Enzymatic digestion of the cell
2. Desaturation of the proteins
What are the 4 types of necrosis
- Cogaulative necrosis
- Liquefactive necrosis
- Caseous necrosis
- Fat necrosis
Coagulative necrosis
The structural boundary of the coagulated cell, tissue, or vessel is maintained, but integral structural proteins are denatured. This type of necrosis often occurs following MIs
Liquefactive necrosis
Cell with a well-defined boundary remains, but is consists of dull, gray-white remains. This is seen with fungal infections and often occurs in the lungs
Fungal, lungs