acute and chronic inflammation

Question 1

Acute Inflammation(AI)

Answer 1

Initial, rapid response: infections/tissue damage
• Within minutes/hours
• Short duration: several hours/ few days
• Exudation of fluid & plasma proteins (oedema)
• Emigration of leukocytes (neutrophils)
• When it fails to clear the stimulus: progress to a protracted phase
of chronic inflammation (CI).

Question 2

Chronic Inflammation

Answer 2

It is of longer duration
• Associated with more tissue destruction
• Presence of lymphocytes and macrophages
• Proliferation of blood vessels
• Deposition of connective tissue

Question 3

Cardinal Signs of Inflammation

Answer 3

Rubor (Redness)
• Tumor ( Swelling)
• Calor (Heat)
• Dolor ( Pain)
• Functio laesa(Loss of function

Question 4

Components of Acute & Chronic Inflammation

Answer 4

Blood vessels dilate: slow down blood flow & increase their
permeability
• Characteristics of the endothelium lining change: leukocytes migrate
into the tissues.
• Leukocytes are activated: Ingest & destroy microbes and dead cells

Question 5

Sequence Of Events of inflammation

Answer 5

Recognition of offending agent by host
cells in extravascular tissue
• Recruitment of leukocytes and plasma
proteins into the tissues
• Removal of the stimulus for inflammation
• Regulation of the response
• Repair of damaged tissue

Question 6

The acute inflammatory response involves

Answer 6

Vascular changes

b) Cellular events (leukocytes)

Question 7

Vasodilation

Answer 7

Induced by the action of several mediators:
histamine on vascular smooth muscle
• Earliest manifestations of AI
• First involves the arterioles and then leads to
opening of new capillary beds in the area.
• Increased blood flow: heat & redness
(erythema)

Question 8

Stasis

Answer 8

Slower blood flow, concentration of red cells in small vessels,
and increased viscosity of the blood.
• Engorgement of small vessels
• Vascular congestion & localized redness
• Neutrophils, accumulate along the vascular endothelium
• Endothelial cells are activated by mediators: express increased
levels of adhesion molecules

Question 9

exudate

Answer 9

an extravascular fluid that has a high protein

concentration & contains cellular debris

Question 10

transudate

Answer 10

fluid with low protein content, little or no

cellular material, and low specific gravity

Question 11

Oedema

Answer 11

an excess of fluid in the interstitial tissue or

serous cavities & can be an exudate or a transudate

Question 12

Pus

Answer 12

purulent exudate: leukocytes, dead cells & microbes

Question 13

Recruitment of Leukocytes to sites of infection and injury

Answer 13

In the lumen: margination, rolling, & adhesion to
endothelium.
2. Transmigration across the endothelium (diapedesis)
3. Migration in interstitial tissues toward a chemotactic
stimulus

Question 14

Diapedesis

Answer 14

Leukocytes insert
pseudopods into the
interendothelial junctions &
squeeze through to assume
a position between the
endothelial cell & the
basement membrane
• Traverse the basement
membrane & escape into the
extravascular space

Question 15

Serous Inflammation

Answer 15

Exudation of cell poor fluid into
spaces created by cell injury or into
body cavities lined
• Increased vascular permeability) or
from the secretions of mesothelial
cells
• Transudate e.g. Skin blister from a
burn

Question 16

Fibrinous Inflammation

Answer 16

Vascular leaks are large/there is a
local pro-coagulant stimulus (e.g.
cancer cells)
• Fibrinogen leaks & Fibrin is formed
• Characteristic of inflammation
lining body cavities e.g.
pericardium
• Lead to scarring - organisation

Question 17

Purulent (Suppurative) Inflammation

Answer 17

An exudate - neutrophils, liquefied debris of
necrotic cells, and edema fluid(pus).
• Bacterial infection (pyogenic)-staphylococci
• Produced by seeding of pyogenic bacteria
• Acute appendicitis

Question 18

Ulcers

Answer 18

A local defect of the
surface of an organ
• Produced by the shedding
of inflamed necrotic tissue.
• Peptic ulcer
• Chronic = Fibroblasts,
scarring and inflammatory
cells

Question 19

Outcomes of Acute Inflammation

Answer 19

Complete resolution - little tissue destruction & removal of
microbes
• Healing by scarring, or fibrosis in tissue incapable of
regeneration
• Chronic inflammation- persistence of agent or disturbance
in healing

Question 20

Substances that initiate & regulate inflammatory reactions

Answer 20

vasoactive amines, lipid products (prostaglandins
and leukotrienes), cytokines (including chemokines), and complement
activation.

Question 21

Causes of Chronic Inflammation

Answer 21

Persistent infections e.g. Mycobacteria
• Hypersensitivity diseases - excessive activation of immune system/
unregulated immune responses against microbes or common
environmental substances
• Prolonged exposure to potentially toxic agents e.g. silicosis
• Sometimes takes specific pattern - granulomatous reaction
• Fibrosis may dominate the late stages

Question 22

Granulomatous Inflammation

Answer 22

Collections of activated
macrophages(epithelioid cells)
• Epithelioid cells & multinucleated giant
cells
• Foreign body granulomas (talc)
• Immune granulomas (cytokines e.g.
IL2

Question 23

Differential of Granulomatous Inflammation

Answer 23

Limited number of conditions that cause it (some life-threatening)
• TB granuloma, referred to as a tubercle
• Leprosy
• Syphilis
• Disease of Unknown aetiology - Sarcoidosis
• Crohn disease

Question 24

pyrogens

Answer 24

Substances that induce fever

Question 25

Acute phase proteins

Answer 25

C-reactive protein (CRP)

• Fibrinogen
• Serum amyloid A (SAA) protein