Introductory clinical sciences

Question 1

What are steps of acute inflammation?

Answer 1

• vascular component: dilation of vessels
• exudative component: vascular leakage of protein-rich fluid
• Neutrophil polymorph: cell type recruited to tissue

Question 2

What is acute inflammation?

Answer 2

It is an initial response to tissue injury

• early onset (seconds to minutes)
• short duration (hours to days)
• cells involved = neutrophils and monocytes

Question 3

What can cause acute inflammation?

Answer 3

• microbial infections: bacterial, viruses
• hypersensitivity reactions: parasites
• physical agents: trauma, heat, cold
• chemicals: corrosives, acids
• bacterial toxins
• tissue necrosis: ischaemic

Question 4

What is the appearance of acute inflammation?

Answer 4

Rubor: redness (due to dilation of small vessels)
Calor: heat, only seen in periphery
Tumor: swelling; results from oedema or physical mass
Dolor: pain
Loss of function

Question 5

What is the acute inflammatory response process?

Answer 5

• changes in vessel calibre (gets wider): increased vessel flow
• increased vascular permeability: formation of fluid exudate
• formation of cellular exudate: emigration of neutrophil polymorphs

Question 6

What are the 4 steps of neutrophil polymorph emigration?

Answer 6

1. Migration of neutrophils
2. Adhesion of neutrophils
3. Neutrophil emigration
4. Diapedesis

Question 7

Why does migration fo neutrophils occur?

Answer 7

Due to increase in plasma viscosity and slowing of flow due to injury, neutrophils migrate to plasmatic zone

Question 8

Why does adhesion of neutrophils occur?

Answer 8

Adhesion to the vascular endothelium occurs in venules - called pavementing

Question 9

What happens in neutrophil emigration?

Answer 9

Neutrophils pass through endothelial cells, onto the basal lamina and then the vessel wall

Question 10

What is diapedesis?

Answer 10

RBCs may also escape from vessels, this is a passive process and indicates severe vascular injury

Question 11

What are the 4 possible outcomes of acute inflammation?

Answer 11

• resolution
• suppuration
• organisation
• progression

Question 12

What happens in resolution?

Answer 12

• This is where there is complete restoration of tissues to normal
• there is minimal cell death and rapid destruction of the causal agent

Question 13

What is suppuration?

Answer 13

• formation of pus
• this becomes surrounded by a pyogenic membrane, which is the start of healing
• leads to scarring

Question 14

What happens in organisation?

Answer 14

• replacement by granulation tissue

- new capillaries grow into the inflammatory exudate, macrophages migrate and fibrosis occurs

Question 15

What happens in progression?

Answer 15

causative agent is not removed so there is progression to chronic inflammation

Question 16

What is chronic inflammation?

Answer 16

• subsequent and prolonged response to tissue injury
• cells involved: lymphocytes, macrophages, plasma cells
• longer onset, long last effects

Question 17

What are the causes of chronic inflammation?

Answer 17

primary chronic inflammation
- resistance to infective agent e.g. TB, leprosy
- endogenous materials e.g. necrotic tissue
- exogenous materials e.g. asbestos, silica
- autoimmune conditions e.g. Hashimoto’s, rheumatoid arthritis
- primary granulomatous diseases e.g. Chron’s, sarcoidosis
Transplant rejection

Question 18

What is the macroscopic appearance of chronic inflammation?

Answer 18

• chronic ulcer
• chronic abscess cavity
• granulomatous inflammation
• fibrosis

Question 19

What is the microscopic appearance of chronic inflammation?

Answer 19

• characteristically lymphocytes, plasma cells and macrophages
• exudation is not a common feature
• evidence of continuing destruction
• possible tissue necrosis