Acute inflamation mw % XXXXXXXXXXXXXXXXXXXXXXXXXXXX Flashcards Preview

ME2308 Principles of Disease > Acute inflamation mw % XXXXXXXXXXXXXXXXXXXXXXXXXXXX > Flashcards

Flashcards in Acute inflamation mw % XXXXXXXXXXXXXXXXXXXXXXXXXXXX Deck (28)
Loading flashcards...
1

 What is the Definition of acute inflammation?

•Series of protective changes occurring in living tissue as a response to injury.

 

 

2

What are the important signs of inflammation?

•Rubor   - redness

•Calor   - heat

•Tumor   - swelling

•Dolor   - pain

•Loss of function

3

 What are the Causes - aetiology -
of acute inflammation?

•Micro-organisms.

•Mechanical  - trauma - injury to tissue.

•Chemical - upset stable environment

•Physical - extreme conditions

•Dead tissue

•Hypersensitivity

 

4

Outline some feutures of acute inflammation?

•Series of microscopic events

•Localised to affected tissue

•Take place in the microcirculation

•Result in the clinical symptoms and signs of acute inflammation - the cardinal signs

5

 What is the microcirculation?

•Capillary beds, fed by arterioles and drained by venules. 

6

What are the overall steps in acute inflamation?

•Changes in vessel radius - flow

•Change in the permeability of the vessel wall - exudation

•Movement of neutrophils from the vessel to the extravascular space

7

Explain the changes in vessel radius in acute inflamation?

1. Transient arteriolar constriction.

2.Local arteriolar dilatation- causes increased local tissue blood flow

3. Relaxation of vessel smooth muscle

 

8

What is the advantage of increased permeability in acute inflamation?

•Locally produced chemical mediators cause an endothelial leak followed by the net movement of plasma from capillaries to extravascular space( Exudation). 

9

What is the effect of exudation?

•Oedema formed

•Oedema is accumulation of fluid in the extravascular space

•Explains swelling of tissue in acute inflammation

•Swelling causes pain - reduce function

10

Describe the phases of emigration of neutraphils?

•Margination - neutrophils move to endothelial aspect of lumen

•Pavementing - neutrophils adhere to endothelium

•Emigration - neutrophils squeeze between endothelial cells - active process - to extravascular tissues. 

11

What is the resolution of acute inflammation?

•Inciting agent isolated & destroyed

•Macrophages move in from blood and phagocytose debris; then leave

•Epithelial surfaces regenerate

•Inflammatory exudate filters away

•Vascular changes return to normal

•Inflammation resolves

12

What are the benefits of acute inflammation?

•Rapid response to non-specific insult

•Cardinal signs and loss of function

–transient protection of inflamed area

•Neutrophils destroy organisms and denature antigen for macrophages

•Plasma proteins localise process

  • Resolution and return to normal

13

What are the outcomes of acute inflamation?

•Resolution

•Suppuration-formation of pus.

•Organisation

•Chronic inflammation

14

Inflammation at various anatomical locations

•“structure”-itis

  • appendix   -appendicitis

•Lungs   -pneumonia

•Pleural cavity   -pleurisy

15

What do neutrophils do?

•Mobile phagocytes

–recognise foreign antigen

–move towards it - chemotaxis

–adhere to organism

•Release granule contents

•Phagocytose & destroy foreign antigen

16

What are the Consequences of neutrophil action?

•Neutophils die when granule contents released.

•Produce a “soup” of fluid, bits of cell, organisms- pus.

•Might extend into other tissues, progressing the inflammation

17

What is the role of plasma proteins in inflammation?

•Fibrinogen - coagulation factor - forms fibrin and clots exudate - localises inflammatory process

•Immunoglobulins in plasma specific for antigen - humoural immune response 

18

Where do mediators of acute inflmation come from?

• Endothelial cell surface membrane

• Released from cells

• In the plasma

19

 What are the collective effects of mediators?

•Vasodilatation

•Increased permeability

•Neutrophil adhesion

•Chemotaxis

•Itch and pain

•Mediators had positive and negative effects

•Result is a dynamic balance

•Favours and inhibits acute inflammation

•relative to need

20

What are the immediate systemic effects of inflammation?

•Pyrexia - raised temperature

•Feel unwell.

•Neutrophilia - raised white cell count

–bone marrow releases/produces.

21

What are the longer term effects?

  • Lymphadenopathy which is a regional lymph node enlargement–immune response
  • Weight loss - catabolic process
  • Anaemia

22

 Explain suppuration as an outcome to acute inflamation?

•Pus formation

–dead tissue, organisms, exudate, neutrophils, fibrin.

•pyogenic membrane(fibrin) surrounds pus

–capillary sprouts, neutrophils, fibroblasts

–Walls off pus

23

What is an abscess?

•Collection of pus (suppuration) under pressure

•Single locule, multiloculated

•“points” and discharges

•Collapses - healing and repair

24

Explain organisation as an outcome to acute inflamation?

•Granulation tissue characteristic

•Healing and repair

•Leads to fibrosis and formation of a scar

25

What is granulation tissue?

•“universal patch” – repair kit – for all damage

•Formed of:

–new capillaries - angiogenesis

–fibroblasts and collagen

–macrophages

26

Explain dissemination as an outcome of acute inflammation ?

•Spread to bloodsteam - patient “septic”

•Bacteraemia - bacteria in blood

•Septicaemia - growth of bacteria in blood

•Toxaemia - toxic products in blood

27

What are the effects of systemic infection?

•Shock - inability to perfuse tissues

•Clinical picture of early septic shock

–peripheral vasodilatation

–tachycardia - high heart rate

–hypotension - low blood pressure

–often pyrexia

–sometimes haemorrhagic skin rash

28

 What are the outcomes of septic shock?

•Rapidly fatal

•Tissue hypoxia - cell death

•Haemorrhage

•Requires urgent intervention and support

–awareness and early recognition

–ability of young people to compensate

 - admit to hospital and intensive care