wk1: AED - Inflammation

Question 1

Name 7 causes of inflammation

Answer 1

Hypoxia
Chemicals and Drugs
Physical Agents
Microbiologic Agents
Immunological Agents
Genetic Defects
Nutritional imbalances

(so same as in cell injury)

Question 2

Name 5 classic signs of inflammation

Answer 2

Redness, Heat, Swelling, Pain, Loss of function

Question 3

What 3 processes can be activated by cellular injury? Can they all be activated at once?

Answer 3

1. Mast cell degranulation
2. Activation of plasma systems
3. Release of cellular components

Any number of these may be activated in cellular injury (1-3). They may also activate in varying amounts (e.g. more or less mast cell degranulation)

Question 4

What specific plasma systems can be activated by cellular injury? [3]

Answer 4

Complement system
Clotting system
Kinin system

Question 5

How can cellular injury affect blood vessels?

Answer 5

Vasodilation
Increase vascular permeability (vessels become leaky, can result in oedema and pain)
Cellular infiltration (pus. If neutrophils)
Thrombosis (clots)
Stimulation of nerve endings (causing pain, itch)

Question 6

Describe the basic immune response for the following:
A: Bacterial infection
B: Immunological/hypersensitivity injury
C: Physical trauma
D: Viral infection

Answer 6

A: toxins, many neutrophils
B: more eosinophil and basophil involvement
C: more oedema, haemorrhage
D: NKT cells, T cells, sometimes haemorrhagic

Question 7

How might chronic inflammation arise? [2]

Answer 7

Failure to remove injurious agent
Failure to remove by-products of infl. response (exudate) which are now invoking infl. themselves

Question 8

What is a good indicator for chronic inflammation?

Answer 8

Presence of lymphocytes/plasma cells and macrophages (a feature of a primary cell-mediated immune response)

Question 9

In what type of inflammation might you see granuloma formation? Acute or chronic?

Answer 9

Chronic. A granuloma is a collection of macrophages that forms when the immune system attempts to wall off substances perceived as foreign but is unable to eliminate

Question 10

In what type of inflammation might you see giant multinucleated cells? Acute or chronic?

Answer 10

Chronic

Question 11

What happens to successful cell recovery in acute inflammation when cells cannot regrow?

Answer 11

Healing by repair - results in scar formation and loss of specialised function of the cells.

Question 12

Describe Mast Cells in terms of their:
- appearance
- when they are prevalent

Answer 12

Particularly prevalent in allergy-driven hypersensitivity. Histologically similar to basophils (apart from lacking bi-lobed nucleus), characteristic blue stain, granular appearance

Question 13

Describe Basophils in terms of their:
- appearance
- when prevalent

Answer 13

Less common than eosinophils in the eye. But demonstrated in acute allergy-driven conjunctivitis. Similar to mast cells but nucleus is bi-lobed

Question 14

Describe Eosinophils in terms of their:
- appearance
- prevalence

Answer 14

Particularly prevalent in allergy-driven hypersensitivity and helminth infection. Like basophils, also have a bi-lobed nucleus

Question 15

Describe Neutrophils in terms of their:
- prevalence

Answer 15

Major cell type of inflammatory response, most prevalent in bacterial infections

Question 16

What is Anterior Ischaemic Optic Neuropathy? Describe its clinical features

Answer 16

Is a disorder of the posterior ciliary artery. Characterised by: acute oedematous reaction + haemorrhage (splinter) of papillary vessels

Question 17

In hypoxia, what signs are there of acute inflammation taking place? [2]

Answer 17

significant loss of RGCs and retinal thinning

Question 18

In trauma (lacerating injury), what signs are there of acute inflammation taking place? [4]

Answer 18

Swelling and redness
Extensive haemorrhage
Plasma exudation
Oedema

Question 19

Do lacerating lesions always involve neutrophils as part of the acute inflammatory response?

Answer 19

No. Neutrophils will only get involved if the lesion becomes infected

Question 20

In a bacterial corneal ulcer, what signs are there of acute inflammation taking place? [4]

Answer 20

inflammatory response involves neighbouring tissues (b/c no corneal blood supply)
Neutrophil exudation from iris blood vessels – forms hypopyon (that white meniscus thing)
Redness and oedema of conjunctiva – vasodilation and junctional loosening
Migration of Neutrophils

Question 21

In a bacterial infection of conjunctiva, what signs are there of acute inflammation taking place? [2]

Answer 21

Epithelial oedema (chemosis)
Neutrophil invasion (of neutrophils from substantia propria invading into epithelial layers)

Question 22

In a chemical corneal injury, what signs are there of acute inflammation taking place? [1]

Answer 22

Neutrophil infiltration from ocular surface vessels (driven by “chemoattractants” released by injured corneal tissue)

Question 23

How might a chemical toxicity injury vary in severity?

Answer 23

Based on if chemical is acidic or alkaline: Acidic = milder, Alkaline = more severe

Question 24

How might corneal perforation occur as a result of chemical toxicity?

Answer 24

Direct toxic damage exacerbated by proteases released by neutrophils may contribute to corneal perforation

Question 25

What signs are there of acute inflammation taking place in membranes?

Answer 25

fibrinous exudate following acute inflammation - pseudomembrane is not firmly attached to underlying epithelium, while true membrane is

Question 26

In anterior uveitis, what signs are there of acute inflammation taking place?

Answer 26

initial infl. = neutrophil exudation from uveal vessels
later stage infl = largely macrophage response

Question 27

How can we differentiate between acute and chronic uveitis?

Answer 27

They differ in their keratic precipitates, which differ in size and colour - reflecting different cell types

Question 28

How does chronic non-granulomatous anterior uveitis present pathologically? [2]

Answer 28

Keratic precipitates largely consisting of macrophages and lymphocytes (not neutrophils as in acute anterior uveitis)
Chronic infl. in iris leads to ischaemia + atrophy of iris stroma + dilator muscle

Question 29

How common is inflammation of the episclera?

Answer 29

Relatively common

Question 30

In episcleritis, what signs are there of chronic inflammation? [1]

Answer 30

infiltrate of lymphocytes/plasma cells

Question 31

How does chronic granulomatous conjunctivitis present pathologically? [2]

Answer 31

Distinct sub-epithelial granulomatous regions - epithelioid cells and multinucleated/giant cells surround fibrous “wall” of tissue
Lymphocytes also present

Question 32

What is chronic granulomatous inflammation secondary to? (i.e. what causes it?)

Answer 32

Blocked meibomian gland (chalazion)

Question 33

What type of mediated response occurs in vernal keratoconjunctivitis?

Answer 33

acute, IgE mediated response

Question 34

How does vernal keratoconjunctivitis affect the inner eyelid?

Answer 34

“cobblestone” papillae accumulations of eosinophils and some basophils (often indicative of an allergic response)

Question 35

What happens to the choroid and retina following repair/healing from a case of toxoplasmosis?

Answer 35

Toxoplasma cysts form in choroid and retina following repair. Note: that reactivation of toxoplasmosis may occur in future

(*slide has a good retinal image showing this)