Exam 2 (Lecture 12) - Nomenclature of Inflammation/Exudates Flashcards
What is inflammation?
Injury or death of cells caused by infectious microbes, mechanical trauma, heat, cold, radiation, or cancerous cells; can initiate a well-organized cascade of fluidic and cellular changes within living vascularized tissue called acute inflammation.
Results in the accumulation of fluid, electrolytes, plasma proteins, and leukocytes in extravascular tissue.
What is the purpose of inflammation?
- Inflammation is often a protective mechanism
- Biologic purpose
- dilute, isolate, and eliminate the cause of injury - Repair tissue damage resulting from the injury
- Without inflammation, animals would not survive their daily interactions with environmental microbes, foreign materials, and trauma and with degenerate, senescent, and neoplastic cells (important in getting rid of neoplastic cells)
What are the 5 cardinal signs of inflammation?
1) Redness
2) Heat
3) Swelling
4) Pain
5) Loss of function
What are the outcomes of acute inflammation if the injurious substance is removed?
1) Temporary tissue injury > parenchymal cell death > stroma and basement membranes are NOT damaged > repair and healing wholly by regeneration of parenchymal cells
2) Temporary tissue injury > parenchymal cell death > stroma and basement membrane ARE damaged > repair and healing by regeneration of parenchymal cells AND modest fibrosis
- scar
What is the outcome of acute inflammation if the injurious substance is NOT removed?
Sustained tissue injury > Parenchymal cell death with stromal and basement membrane damage > chronic and/or granulomatous inflammation (contributes further to sustained tissue injury) > repair and healing by extensive fibrosis without useful regeneration of parenchymal cells
- granuloma
What happens during acute inflammation in an arteriole?
Transudate is produced
- arteriolar constriction - mast cell degranulation - increased vascular permeability - increased inter endothelial spaces - chemotaxis for neutrophils **Fluid leakage
What happens during acute inflammation in a capillary?
Exudate is produced
- Platelet aggregation - Emigration of neutrophils - Diapedesis of erythrocytes
What happens during acute inflammation in a venule?
Exudate is produced
- Emigration of lymphocytes - Infiltration by macrophages - Fibrin deposition (by fibrinogen) - Fibrosis
What happens if you can’t get rid of the injurious substance (ie splinter)?
Chronic inflammation
After 1 week = chronic inflammation
- Chronic inflammation is inflammation of prolonged duration (weeks to months to years) that occurs:
- when the acute inflammatory response fails to eliminate the inciting stimulus - after repeated episodes of acute inflammation - in response to unique biochemical characteristics and/or virulence factors in the inciting stimulus/microbe
What are the 6 components of a morphologic diagnosis?
1) Duration
2) Distribution
3) Degree of severity
4) Exudate
5) Modifier
6) Tissue and process
(DDD EMT)
What are some examples of degree, duration, distribution, exudate, modifier, and tissue?
Degree:
- minimal
- mild
- moderate
- severe (marked)
Duration:
- acute
- subacute
- chronic
- chronic-active
Distribution:
- focal
- multifocal
- locally extensive
- diffuse
Exudate
- serous
- catarrhal (mucous)
- fibrinous
- suppurative (purulent)
- granulomatous
Modifier:
- necrotizing
- bronchointerstitial
- hemorrhagic
- embolic
Tissue:
- nephritis
- cystitis
- enteritis
- pneumonia
- hepatitis
What do exudates tell us about the length of the injury?
Exudates can tell us if the inflammation is acute or chronic.
Acute inflammation (less than 1 week duration)
- serous
- fibrinous
- mucoid (catarrhal)
- purulent (suppurative)
- hemorrhagic
** Or combination: ex: fibrinosuppurative
Chronic Inflammation (greater than 1 week duration)
- lymphocytic/plasmacytic
- granulomatous
- fibrosing
- proliferative
Describe acute inflammation.
Often represents:
- A continuum of progressive changes of the same type of inflammation occurring over time
OR
- Different types of inflammatory responses occurring concurrently in the same or different areas of an affected tissue.
Therefore, rhinitis, for example, could progress in a sequence from serous to catarrhal to mucopurulent to purulent.
What is serous inflammation?
Pattern of acute inflammation in which the tissue response consists of the leakage or accumulation of fluid with a low concentration of plasma and no to low numbers of leukocytes.
- TRANSUDATE (more fluid than cells/proteins); low specific gravity
What are the causes of serous inflammation?
1) Thermal injury to skin, such as burns and photosensitization, in which the lesion can appear as fluid-filled blisters, OR
2) Acute allergic responses characterized by watery eyes and a runny nose with a clear, colorless transudate.
