[A] 1.50 Vascular changes and exudation in the acute inflammation

Question 1

Infectious inflammation caused by…

Answer 1

Pathogens

Question 2

Non-infectious inflammation caused by…

Answer 2

• Foreign body
• Trauma
• UV radiation
• Tumour
• Irritation
• Allergy

Question 3

Acute inflammation: Aim

Answer 3

• Elimination of toxic agents, necrotic tissues and cells
• Rapid protection until an effective immune response
• Restrict toxins & pathogenic inflammatory agents to the site of injury

Few seconds after injury

Question 4

Effective immune response =

Answer 4

Subacute inflammation

Question 5

Acute inflammation: Effect on a microscopic scale

Answer 5

• Diluting & inactivating biologic and chemical toxins
• Killing & sequestrating microbes and neoplastic cells
• Degrading foreign body
• Providing wound healing (growth) factors to ulcerated surfaces and traumatised tissue

Question 6

Modified inflammatory reactions

Answer 6

Caused by:

• Anti-inflammatory treatments
• Drugs

Question 7

Panniculitis

Answer 7

Inflammation of adipose tissue

Question 8

Stomatitis

Answer 8

Inflammation of oral cavity mucosa

Question 9

Typhlitis

Answer 9

Inflammation of Caecum

Question 10

Proctitis

Answer 10

Inflammation of Rectum

Question 11

Omphalitis

Answer 11

Inflammation of navel

Question 12

Pyelitis

Answer 12

Inflammation of renal pelvis

Question 13

Salpingitis

Answer 13

Inflammation of uterine tube

Question 14

The four cardinal signs of acute inflammation

Answer 14

• Rubor (Redness)
• Tumor (Swelling)
• Calor (heat)
• Dolor (pain)
• (+ Loss of function)

Question 15

The inflammatory response consists of which two main components?

Answer 15

• Vascular reaction
• Cellular reaction

Parallel, coherent processes

Question 16

Identification of the inflammatory stimuli can be by…

Answer 16

• PAMPs (Pathogen-associated molecular patterns)
• DAMPs (Damage associated molecular patterns)
• TLRs (Toll-like receptors) & other PRRs (pattern recognition receptors)

Question 17

PAMPs

Answer 17

Molecules associated with groups of pathogens

• Recognised by cells of the innate immune system

Question 18

DAMPs

Answer 18

Nuclear/cytosolic proteins

• Cellular stress, damage and necrotic cell death cause release of DAMP molecules or alarmins

Question 19

Changes in vascular flow and calibre

Answer 19

• Begin early after injury
• Vasodilation first involves the arterioles → opening of new capillary beds in the injured area
• Increased blood flow (heat and redness)

Question 20

Vasodilation (cell-derived mediators)

Answer 20

Induced by the action of several mediators

• Histamine*
• Serotonin*
• Prostaglandins
• Nitric oxide

*Secreted by mast cells, basophil granulocytes & platelets

Question 21

Cytokines

Answer 21

Small proteins used in cell signalling

• Produced by:
  
  • Macrophages
  • B-lymphocytes
  • T-lymphocytes
  • Mast cells
  • Endothelial cells
  • Fibroblasts

Question 22

Examples of cytokines in inflammation

Answer 22

• Interferons
• Chemokines
• Interleukins
• Lymphokines
• Tumour necrosis factors (TNF)

Question 23

Vascular changes of microcirculation during inflammation

Answer 23

• Haemostasis
• Venula-hyperpermeability
• Microvascular exsudation - Inflammatory exsudate (oedema)

Question 24

Haemostasis

Answer 24

• Vasodilation & loss of fluid → Conc. of blood cells in the vessel of microcirculation
• Increased viscosity of the blood & slower blood flow

Question 25

Increased vascular permeability

Answer 25

Vascular leakage * Hallmark of acute inflammation * Leads to the escape of protein-rich fluid (exudate) into the extravascular tissue * Increased interstitial hydrostatic pressure and endothelial dysfunction * Extravascular fluid = Inflammatory oedema

Question 26

Causes of endothelium becoming leaky during inflammation

Answer 26

* Endothelial gaps form in postcapillary venules * Direct endothelial injury (burns/lytic bacterial infections) * Leukocyte mediated endothelial injury

Question 27

Acute inflammation - Cellular events

Answer 27

The critical function of the inflammation is to deliver leukocytes to the site of injury * Leukocytes ingest agents, kill bacteria and other microbes and remove necrotic tissue

Question 28

Acute inflammation - Cellular events

Answer 28

1. In the vascular lumen: Leukocyte margination, rolling and adhesion 2. Transmission across the endothelium (Leukocytadiapedesis) 3. Migration in the interstitial tissues 4. Leukocyte activation & phagocytosis 5. IC degradation

Question 29

Leukocyte adhesion deficiency (LAD)

Answer 29

* Defects in the leukocyte adhesion process * Marked leukocytosis and recurrent infections * Impaired migration of leukocytes from the blood vessels to sites of infection * Requires adhesion of leukocytes to the endothelium

Question 30

Leukocyte adhesion deficiency (LAD) as a congenital defect

Answer 30

* Holstein calves (Bovine LAD (BLAD)) * Irish setters (Canine LAD (CLAD))

Question 31

Clinical signs of BLAD

Answer 31

* Gingivitis * Tooth loss * Oral ulcers * Enteric ulcers * Leukocytosis * Pneumonia