Lecture 10 2/16/24 Flashcards
What leads to exudate?
accumulation of edema fluid, fibrin, and neutrophils in the extracellular space
Which cause of edema leads to exudate?
increased vascular permeability/inflammation
What are the characteristics of exudate?
-high protein conc.
-lots of cells and debris
-high specific gravity
-cloudy appearance
How does vasculitis differ from vascular permeability?
-vasculitis is an inflammatory response that targets the wall of the blood vessel
-vascular permeability is not associated with damage to the vessel
What is chemotaxis?
migration of leukocytes to the site of injury following a concentration gradient of chemokines and chemoattractants
Which chemokines are important for chemotaxis?
-IL-8: neutrophils/leukocytes
-IL-16: CD4+ T cells
-IL-17: monocytes/neutrophils
-chemerin: DCs and macrophages
What role does the leukotriene LTB4 play in chemotaxis?
-made by neutrophils
-recruits more neutrophils and macrophages
What are the characteristics of phagocytosis?
-carried out by neutrophils and macrophages
-cells eat organisms and cellular/necrotic debris
-specific process involving recognition, attachment, and opsonins
What are the general steps of phagocytosis?
-recognition and attachment
-engulfment
-killing and degradation
What are the effects of sloppy phagocytosis?
cell death and degradation of extracellular matrix due to intracellular/extracellular release of lysosomal enzymes
What are the characteristics of serous inflammation?
-leakage/accumulation of fluid with low plasma protein and no/few leukocytes
-practically transudates
-seen with thermal injury to skin and acute allergic responses
What are the characteristics of catarrhal inflammation?
-secretion/accumulation of thick, gelatinous fluid containing abundant mucus/mucins
-occurs in tissue with abundant goblet cells/mucous glands
-seen with chronic allergic and autoimmune disease
What are the characteristics of fibrinous inflammation?
-accumulation of fluid with high plasma proteins and no to few leukocytes
-lots of fibrin
-primarily on serous membranes of body cavities
-due to increased vascular permeability
-can be infectious or non-infectious in cause
What are the characteristics of fibrinous/fibrinonecrotic inflammation?
-fibrin covering an ulcer
-plaque of fibrin, neutrophils, and necrotic material
-typically on mucosal surfaces
What are the characteristics of hemorrhagic inflammation?
-involves hemorrhage
-often seen with necrosis (necrohemorrhagic)
-necrosis erodes blood vessels
How does hemorrhage differ from hemorrhagic inflammation?
-hemorrhage simply involves damage to blood vessel and blood leaking into tissues
-hemorrhagic inflammation is due to triggering of immune response and is often associated with necrosis of tissue
What are the characteristics of necrotizing inflammation?
-involves necrosis
-usually in response to physical trauma
-can be fibrinonecrotizing or necrohemorrhagic
How does necrosis differ from necrotizing inflammation?
-necrosis is simply cell death due to a variety of causes
-necrotizing inflammation involves necrosis and inflammation, with vessel damage leading to fibrin and blood leakage
What are the characteristics of suppurative/neutrophilic/pyo-inflammation?
-accumulation of fluid with high conc. of plasma protein and high numbers of leukocytes/neutrophils
-usually in response to bacteria
-pus/purulent
-can be mixed with fibrin or necrosis
How does suppurative differ from neutrophilic?
-suppurative occurs when pus has formed, causing tissue destruction
-neutrophilic is when neutrophils are just “hanging” out” in tissues
Why do avian/exotic species with heterophils not have suppurate/pus-associated inflammation?
-lack myeloperoxidase
-do not liquefy exudate
Which steps of inflammation lead to serous, fibrinous, hemorrhagic, or necrotizing inflammation?
-initiation
-vasodilation
-increased vascular permeability
Which steps of inflammation lead to suppurative inflammation?
-activation of leukocytes
-diapedesis
-chemotaxis
-phagocytosis
Which types of inflammation occur with a mix of all steps of inflammation?
-fibrinosuppurative
-necrosuppurative
-necrohemorrhagic
What are the potential next steps following acute inflammation?
-resolution
-progression to chronic inflammation
-healing/repair
What occurs during resolution?
-removal of inciting agent
-neutralization of inflamm. mediators
-return of vascular integrity
-leukocytes stop transmigrating
-apoptosis of neutrophils
-removal of edema fluid/leukocytes/foreign material/necrotic debris by macrophages and lymphatic system
Which type of agents lead to resolution?
short-lived, rapidly decayed agents
What is an abscess?
a circumscribed collection of pus with marked neutrophilic response
What is important about the fibrous capsule surrounding an abscess?
indicates chronicity
