Inflammation Flashcards
- Name 4 reasons why Inflammation is important?
- Pathogenic basis of many diseases
- Roles in triggering IMMUNITY
- A set of processes that keeps us alive
- Most AI drugs work by preventing formations/actions of mediators
- Works on a daily basis
- Deficiency in a segment of inflammation can cause severe diseases
- Complex relationship inflammation / cancer
- Dysregulation of inflammation: lethal/chronic, debilitating diseases
- What are the three main causes of acute inflammation?
Injury, Infection or Foreign Body
- Define INFLAMMATION
the reaction of vascularised living tissues to local injury or infection, characterised by the movement of fluid & leukocytes from the blood into the affected tissue.
- Describe the Formation and Components of Pus
- Essentially DNA & debris.
- Bacteria remnants in interstitial fluid as a result of killing; constitutes dead & dying microorganisms
- Leukocytes also undergo apoptosis and die; their remnants in pus (neutrophils, e.g.)
- Enzyme accumulates in the pus that gives it the yellow colour, e.g. myeloperoxidase from neutrophils
- Dead & damaged tissue
- Plasma proteins due to ‘leakiness’ of vessel; antibody, complement system products, fibrinogen, fibrin
- Where are leucocytes produced?
a) Spleen
b) Lymph nodes
c) Bone marrow
d) Liver
e) All of the above
c) Bone marrow.
It is signalled to produce more leucocytes when required.
The spleen is a store of leucocytes; they accumulate in the body in inflammatory periods, but destroyed when no longer needed to normal homeostatic levels of WBCs
- Monocytes undergo a maturation process stimulated by chemical signs, after which it turns into a…
a) macrophage
b) basophil
c) granulocyte
d) remains a monocyte
a) macrophage.
The ‘garbage collectors’ of the body, removing bacterial remnants by phagocytotic processes. They are very motile, and actively search for debris.
- What subtype of leucocyte are the following:
a) V large nucleus, several small nucleoli, v small cytoplasm, granular, rare
b) Large nucleus, squashed out cytoplasm, motile, so sometimes oddly shaped
c) V large nucleus relative to cytoplasmic ratio; 80-90% of the cell
d) unusual looking nuclei; multipolar/polylobular or ‘fragmented’ appearance
e) unusual looking nuclei, very granular, pink-ish
a) Basophil
b) Monocyte
c) Lymphocyte
d) Neutrophil
e) Eosinophil
- How do lymphocytes differ in their origin to the group including basophils, neutrophils, eosinophils, monocytes and macrophages?
In Haematopoiesis, all of these cells begin from a Multipotential haematopoietic stem cell (Haemocytoblast). This will differentiate into either a Common Myeloid Progenitor or a Common Lymphoid Progenitor cell.
Myeloid-type differentiate into cells including Erythrocytes, Mast and Myeloblast. The latter further differentiates into the leucocytes listed: basophils, neutrophils, eosinophils & monocytes. Monocytes can even further develop into macrophages.
Lymphoid-type differ into Natural Killer cells, or Small Lymphocytes. These differ into B/T lymphocytes.
- Briefly describe the following routes of dissemination:
a) airways
b) lymphatics
c) venules
a) via external environment, lung & airways or gut
b) via circulation -> right heart -> lung (miliary TB)
c) via left heart -> other organs (miliary TB)
- Which is not a symptom of injury leading to acute inflammation?
a) local swelling
b) local pain
c) red streaks away from local region
d) neutrophilia
e) none of the above
e) none of the above; all were symptoms of acute injury.
NB (c): red streaks away from the site of injury e.g. an infected cut is inflammation of the lymph vessels.
- Inflammation does NOT involve (could be more than one):
a) Destruction of microbes
b) Destruction of host cells
c) Anti-coagulation
d) A set of go & no-go signals (stimulatory/inhibitory)
e) A few specific cell types only
f) Complex cell-cell interactions
c) Inflammation involves coagulation
e) Involves numerous cells, mediators etc; not simply limited to a few types…
Inflammation is v physiological; triggers coagulation cascades/events…
- What are the 4 main elements of the body’s defence against microorganisms?
- BARRIERS: Outer covering of body - skin & mucous membranes (e.g. mouth, GIT), and secretions (mucous, tears).
- “INNATE IMMUNITY”: Inflammatory phagocytes (neutrophils & macrophages) plus plasma proteins (e.g. complement system), and Natural Killer (NK) cells.
- LYMPHATIC SYSTEM: Drainage to lymph nodes - more phagocytes encountered.
- “ACQUIRED IMMUNITY”: (aka ‘adaptive’) - humoral (Ab-mediated) and cellular (leucocyte-mediated) immunity.
- Regarding Thrombosis,
i. Activation of thrombin, formation of fibrin
ii. Release of thromboxane A2 & ADP from platelets
iii. Injury exposes collagen
iv. Blood platelets attach to collagen, forming Initial Haemostatic Plug
v. Aggregation of platelets, deposition of thrombin & stabilisation of initial plug to form “thrombus”
Which outlines the correct order of the above?
a) v, iii, i, ii, iv
b) iii, ii, v, i, iv
c) iii, iv, v, ii, i
d) v, iii, iv, ii, i
e) none of the above
e) none of the above
(d) was the closest, however v. should occur last rather than first.
The correct order of Thrombus formation:
- Injury exposes collagen
- Blood platelets attach to collagen, forming Initial Haemostatic Plug
- Release of thromboxane A2 & ADP from platelets
- Activation of thrombin, formation of fibrin
- Aggregation of platelets, deposition of thrombin & stabilisation of initial plug to form “thrombus”.
- True or false?
a) Strong relationship between Inflammation Coagulation
b) Strong relationship between Inflammation Pain
c) Strong relationship between Inflammation Infection
a) True! Macrophages release important modulators of coagulation.
b) True! There exists an important relationship between mechanisms which cause pain in inflammation, and the mechanisms by which we FEEL pain.
c) FALSE. Whilst a role of the inflammatory response can be to localise and eliminate microorganisms, inflammation also exists against elements like damaged cells, inanimate foreign particles, or antigens.
- Which of the following is a correct difference between the two major classes of inflammation?
a) Chronic - a rapid onset
b) Acute - will always be the same cascade of events
c) Chronic - characterised by movement of fluid & neutrophils out of the blood & into the affected tissue
d) Acute - many macrophages & lymphocytes
b) Acute - will always be the same cascade of events; ‘stereotypic’ response to injury/infection. Acute inflammations always start very quickly, but do not last for very long.
(a) & (c) describe acute inflammation.
(d) describes chronic inflammation (granulomatous)
- Sarah is suspected to have acute appendicitis; a specimen is observed down the microscope. What typical features in the tissue does Dr. Steve visualise?
- neutrophils marginating in blood vessel
- spaces filled with oedema fluid
- muscle bundles pushed apart by fluid (oedema) (can characterise smooth muscle cells as long & elongated w flat nuclei)
- infiltrating neutrophils (high number, and in places they shouldn’t be)
- What is diapedesis?
a) firm adhesion of leucocytes to endothelial walls
b) continuous destruction & repair of normal tissue
c) a delayed, prolonged response to injury or infection
d) the passage of blood cells through the intact walls of the capillaries, typically accompanying inflammation
d) the passage of blood cells through the intact walls of the capillaries, typically accompanying inflammation
Leucocyte-endothelial interactions are a multi-step process. “Transendothelial Migrations” involve at some point, circulating leucocytes slowing down and “rolling” on the surface of endothelial cells, as some adhesion molecules will be present in high concentrations. They will infiltrate into the tissue and contribute to inflammation. The main steps:
- Activation
- Rolling
- Firm adhesion
- Diapedesis in response to tissue-derived chemoattractants
NB: (a) describes step 3 in the above process (preceeding diapedesis), (b) & (c) describe chronic inflammation
- What particular feature of leucocytes can be used to detect the type of inflammation?
a) nucleus
b) granules
c) cytoplasmic processes
d) all of the above
a) nucleus
Acute = mostly polynuclear Chronic = mostly mononuclear (e.g. macrophages; excluding polynucleated giant cells as they are derived from macrophages)
- Inflammation is important in biomedical science. What are its positive roles in promoting host survival?
- Direct role in host defence against microorganisms
- Role in initiating adaptive immune response
- Role in initiating tissue healing mechanisms
- Inflammation is important in biomedical science. What are examples of its deleterious effects on host survival (complications of inflammation)?
Acute:
- appendicitis (possibility of perforation; can lead to septic shock)
- meningitis (intra-cranial pressure; compression of brain stem can lead to interference or respiratory centre)
Chronic:
- tuberculosis (impairment of lung function)
- arthritis (incapacitation)
- initiation of cancer (maybe! under research)
- What major cell types involved in inflammation are correctly described by the following?
i. kill microorganisms.
ii. regulate movement of protein from blood into tissues. express adhesion molecules.
iii. degrade fibrin & debris. kill micro-organisms. secrete regulatory molecules called ‘cytokines’.
iv. secrete collagen
a) i. macrophages, iv. fibroblasts
b) i. fibroblasts, iii. macrophages
c) i. neutrophils, iv. endothelial cells
d) i. neutrophils, ii. endothelial cells
d) i. neutrophils, ii. endothelial cells
iii. macrophages
iv. fibroblasts
- What are the Vasoactive Mediators of Inflammation and their sources?
- Amines: histamine - from mast cells, platelets
- Lipid-derived mediators: prostanoids, leukotrienes - from leucocytes, parenchyma
- Plasma-derived mediators: complement fragments C3a and C5a (the “anaphylatoxins”), kinins 0 from plasma protein precursors
In terms of Vasodilation (arterioles): Histamine, kinins, prostaglandin E2 and I2.
Re Increased Vascular Permeability (post-capillary venules): Histamine, kinins, C3a, C5a, and leukotrienes B4 and C4.