Acute Inflammation

Question 1

Name the causes of acute inflammation

Answer 1

Microbial infections, hypersensitivity reactions, physical and chemical agents

Question 2

What are the symptoms of acute inflammation?

Answer 2

Red (rubar) - dilation of blood vessels
Hot (calor) - Peripheral increase in temperature due to increased blood flow (hyeraemia)
Swollen (tumor) - Due to Oedema
Painful/tender (dolor) - due to stimulation of nerve endings by pressure and chemical mediators
Loss of function.

Question 3

Name the two phases of acute inflammation

Answer 3

Vascular phase - dilation and increased permeability

Exudative phase - fluid and cells escape from permeable membranes.

Question 4

Describe the feature of exudate

Answer 4

High protein content, some of these may be immunoglobins which are important for the destruction of invading organisms. Fibrinogen is converted to fibrin which will cover acutely inflamed organ surfaces. There is a high turnover/drainage as exudate is continuously removed by the lymphatic system.

Question 5

What is fibrinogen?

Answer 5

A glycoprotein that circulates the blood, during tissue or vascular damage it is converted to fibrin by enzymes.

Question 6

Describe the differences between exudate and transudate

Answer 6

Exudate; Net flow of plasma and fluid out of vessels because of increased vascular permeability. There is a high protein content.
Transudate; NO net flow out because of normal vascular permeability. There is a low protein content.

Question 7

What causes increased vascular permeability?

Answer 7

Chemical mediators such as histamine. It stimulates the endothelium cytoskeleton, directly changing but not damaging the endothelium. This is confined to post capillary venules.

Question 8

Describe occurs with the lymphatic system in actue inflammation

Answer 8

Lymphatic vessels dilate as they drain fluid from exudate. Antigens are carried to lymph nodes which are recognised by lymphocytes triggering an immune response.

Question 9

What is lymphangitis?

Answer 9

Inflammation of a lymphatic vessel

Question 10

What is lymphadenitis

Answer 10

Inflammation of a lymph node

Question 11

What is the cellular component of acute inflammation?

Answer 11

Neutrophils which accumulate in extracellular space, this is diagnostic feature of acute inflammation

Question 12

Describe some of the features of Neutrophils

Answer 12

They kill organisms, degrade necrotic tissues, ingest offending agents, produce chemical mediators, toxic oxygen radicals and tissue damaging enzymes.

Question 13

What is margination?

Answer 13

The process of white blood cells adhering to the walls of a blood vessel (the endothelium).

Question 14

What is pavementing?

Answer 14

The flattening of white blood cells

Question 15

Define chemotaxis

Answer 15

The movement of a cell or organism in response to a gradient of a particular substance.

Question 16

Name some chemotactic compounds

Answer 16

Bacterial products, complement components and products of neutrophil activity.

Question 17

Name the four plasma enzymatic cascade systems

Answer 17

Complement system, the kinins, the coagulation factors and the fibrinolytic system.

Question 18

What are opsonins?

Answer 18

A molecule that enhances phagocytosis means that it can be undergone much more efficiently. They bind to specific receptors on leucocytes.

Question 19

Name some major opsonins

Answer 19

The Fc fragment of IgG. C3b which is a fragment of C3 and collectins - a plasma protein that binds to microbial cell walls.

Question 20

What is suppuration?

Answer 20

The formation of pus

Question 21

What is pus made out of?

Answer 21

Neutrophils, bacteria and cellular debris.

Question 22

Name some acute inflammatory responses and how they present

Answer 22

Serous - protein rich fluid exudate
Catarrhal - mucus hypersecretion
Fibrinous - exudate contains plentiful fibrin
Haemorrhagic - severe vascular injury
Suppurative - production of pus
Membranous - epithelium coated by fibrin
Psudomembranous - superficial mucosal slough

Question 23

What occurs when an abscess is drained?

Answer 23

The cavity collapses and is destroyed by organisation and fibrosis

Question 24

What is fibrosis?

Answer 24

Formation of excess fibrous connective tissue which forms in an organ or tissue for repairs

Question 25

Where do deep seated abscesses drain?

Answer 25

Along sinuses or fistulas.

Question 26

what is bronchopneumonia?

Answer 26

A type of pneumonia which causes inflammation of the lungs

Question 27

What is an ulcer?

Answer 27

A local defect or excavation of the surface of an organ or tissue that is produced by the removal of inflammatory tissue.

Question 28

Where are ulcers most commonly encountered?

Answer 28

When there is inflammatory necrosis of the mucosa (mouth, stomach or intestines)
and chronic leg ulceration in patients with circulatory issues

Question 29

Name and describe some of the beneficial effects of acute inflammation

Answer 29

Dilution of toxins which allows them to be carried away by lymphatics, Entry of antibodies due to vascular permeability, Fibrin formation which prevents the movement of microorganisms, Transportation of drugs because of increased vascular permeability, Delivery of nutrients & oxygen aided by increased fluid flow, Stimulation of immune response as fluid exudate containing antigens reach lymph nodes.

Question 30

Describe the harmful effects of acute inflammation

Answer 30

Digestion of normal tissue, Swelling (laryngeal oedema and brain swelling, and inappropriate inflammatory responses (allergic reactions)

Question 31

Describe some of the systemic effects of acute inflammation

Answer 31

Pyrexia - rise in body temp even by a few degrees can improve efficiency of leukocytes and impairs the replication of offending micro-organisms.
It can also cause constitutional syptoms such as malaise, anorexia and nausea. The weight loss is due to negative nitrogen balance, common with chronic. Reactive hyperplasia of the reticuloendothelium system. Haematological changes and increased erythrocyte sedimentation rate.