Term
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Definition
•Factors that effect ischemic injury:
–Rate and duration
–Collateral circulation
–Systemic circulation
–Coagulation
–Temperature
•Cerebral blood flow (CBF) is tightly regulated to match metabolic demand in the brain (autoregulation). However, autoregulation is compromised around core of infarction.
•This area around the infarct core is called the ischemic penumbra (IP) and has some preservation of energy metabolism.
•The IP represents a ‘window of opportunity’ for salvaging neurological tissue/function if the ischemia is reversed.
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Term
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Definition
•Considered to be inflammation of a prolonged duration (weeks-months) in which active inflammation, tissue destruction, and attempts at repair proceed simultaneously (may be cyclical in nature).
•Occurs under the following settings:
–Persistent infections
–Prolonged exposure to endogenous or exogenous toxic agents
–Autoimmune disease
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Term
Role of Macrophage in Chronic Inflammation |
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Definition
•Macrophage is a central feature due to a large number of substances released from activated macrophage
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Term
Mechanisms of Macrophage Accumulation |
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Definition
•Recruitment- adhesion molecules and chemotactic agents.
•Proliferation- increased cell division
•Immobilization- retention of cells in response to chemical mediators
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Term
Granulomatous Inflammation |
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Definition
•Granuloma- a focal area of granulomatous inflammation. Consists of macrophage aggregation resembling epithelium-like morphology surrounded by mononuclear leukocytes (primarily lymphocytes and often plasma cells).
•Examples are tuberculosis, leprosy, syphilis, cat-scratch disease
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Term
Morphological Patterns of Inflammation |
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Definition
•Serous Inflammation- outpouring of fluid derived from blood serum or secretions of mesothelial cells lining various cavities (effusion).
•Fibrinous Inflammation- Fibrinous exudate due to significant vascular leaks or procoagulant stimulus. Characteristic in inflammation of cavities, e.g. pericardium and pleura.
•Suppurative/Purulent Inflammation- Production of large amounts of pus or purulent exudate (usually neutrophils, necrotic cells, and edema fluid). Abscesses are focal areas of purulent inflammation tissue.
•Ulcers- Local defect or excavation of surface organ tissue produced by the sloughing of inflammatory necrotic tissue. Common in gastrointestinal and gentiourinary tracts. Can also be seen in lower extremities of persons with circulation disorders that predispose to extensive necrosis.
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Term
Resolution of Inflammation |
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Definition
1.Restore normal permeability
2.Resolve edema via lymphatics
3.Resolve edema via pinocytosis (secondary)
4.Phagocytosis of apoptotic neutrophils
5.Phagocytosis of necrotic debris by macrophage
6.Disposal of macrophages.
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Term
How do Tissues Respond to Injury? |
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Definition
-Adaptation
-Cell Death (If injury is big or can't adapt) |
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Term
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Definition
- Autophagy results from different intracellular signaling pathways in cardiac ischemic compared with reperfusion and has different effects |
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Term
UPR/ER Stress and Ischemia |
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Definition
•During neuronal ischemia accumulation of misfolded proteins in the ER activates GRP78 stimulating the unfolded protein response (UPR).
•PERK- Protein synthesis inhibition
•IRE-1- Increased XBP-1 expression and Caspase 12 activity.
•ATF6- cleaved in golgi and then translocated to nucleus to bind ER stress promoter elements
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Term
Cell Adaptations of Growth and Differentiation |
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Definition
•Hyperplasia- an increase in the number of cells in an organ. May be physiological or pathological. Most often due to hormonal or growth factor stimulation.
•Hypertrophy- an increase in cell size thus resulting in an increase in organ size. May be physiological or pathological.
•Atrophy- a decrease in cell size due to loss of cell substance. Predominantly pathological with exception of physiological atrophy during early development.
•Metaplasia- a reversible change where one mature cell type is replaced by another mature cell type. Often represents an adaptive substitution of cells which are sensitive to stress by others that are more hardy.
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Term
Summary- Chronic Injury I |
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Definition
•Tissue rescue may be accomplished via alteration of metabolism and function.
•Chronic inflammation may ensue further complicating tissue repair/healing.
•Tissues respond to chronic injury through altering cell function, size, or type.
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