Acute inflammation

Question 1

Define acute inflammation

Answer 1

Reaction of vascularized tissue to injury

Question 2

Inappropriate inflammatory response with no foreign substances to remove is the basis of . . .

Answer 2

Autoimmune inflammation

Question 3

What four things are involved in the formation and clearing of acute inflammation?

Answer 3

1. Pathogen/injury
2. Host inflammatory cells
3. Complement and coagulation cascades
4. Chemokines and cytokines

Question 4

Three things involved in immediate tissue reaction

Answer 4

1. Fluid
2. Plasma proteins
3. Innate immune cells

Question 5

Intensity of immune response dictated by these four things

Answer 5

1. Stimulus
2. Duration of the stimulus
3. Genetics of the host local factors
4. Medical interventions

Question 6

Four causes of inflammation

Answer 6

1. Infections
2. Tissue necrosis
3. Foreign bodies
4. Immune reactions

Question 7

Recognition by the innate immune system

Answer 7

DAMPs/PAMPs activate TLRs and other recognition receptors on monocytes

Question 8

Inflammasome

Answer 8

Multi-protein complex characterized by activation of caspase 1; cleaves IL-1 to active form that sets the inflammatory cytokines in action

Question 9

Nitric oxide in the inflammatory response

Answer 9

Mediates vasodilation that increases flow and vascular permeability

Question 10

Three main events of inflammation

Answer 10

1. Vascular dilation and increased blood flow (erythema and warmth)
2. Extravasation of plasma fluid and proteins (edema)
3. Leukocyte (mainly neutrophil) emigration and accumulation

Question 11

Movement of the leukocytes into the extravascular space

Answer 11

TNF alpha and IL-1 beta signal for the leukocytes to move out of laminar flow and roll along vascular wall until they attach and move through the cell space through diapedesis

Question 12

Chemotaxis

Answer 12

Unidirectional movement along a chemical gradient used by

• Bacterial peptides
• Complement proteins, especially C5a
• Proinflammatory cytokine tetrad

Question 13

How does chemotaxis work?

Answer 13

Chemoattractants activate membrane receptors on the innate cells that then activate cytoskeleton, particularly actin, changes that move the cell along the gradient

Question 14

Three phases of leukocyte activity in inflammation

Answer 14

1. Moving out of the blood vessel using diapedesis
2. Releasing acute inflammatory mediators; immediately undergoing checkpoint mechanism to stop acute inflammation
3. Degranulation and quick cleanup moderated by the monocyte/macrophage system

Question 15

Where are extra neutrophils derived during acute inflammation?

Answer 15

More blood can be dumped out from the spleen, which has more neutrophils in it (cannot actually produce more neutrophils)

Question 16

What do neutrophils look like histologically?

Answer 16

They have a lot of different lopes to each nucleus, but has ONLY ONE nucleus

Question 17

What do macrophages look like morphologically?

Answer 17

Have one single, solid, round nucleus

Question 18

Describe the name changes of monocytes.

Answer 18

In the cavity: macrophage

Into a tissue: histocyte

Question 19

Which cells are present at the site of inflammation first, neutrophils or macrophages?

Answer 19

Neutrophils and THEN macrophages

Question 20

Rheologic

Answer 20

Increased delivery of cells per unit time increases the chance that a leukocyte can respond to a signal

Question 21

Most numerous leukocyte in circulation

Answer 21

Neutrophils (“PMNs”)

Question 22

Half lives of neutrophils

Answer 22

12 hours in the blood, 1-2 minutes at the site of inflammation

Question 23

Left shift

Answer 23

Bone marrow pushes immature neutrophils out earlier to deal with acute inflammation

Question 24

Five features of neutrophils at the site of injury

Answer 24

-Phagocytosis
-recognition/attachment of complement
-engulfment/degranulation
killing/degradation by oxidative burst
-NETS

Question 25

Phagolysosome

Answer 25

Part of membrane breaks off to form a bubble with the pathogen in it, which then fuses with the lysosome inside the cell and kills the pathogen

Question 26

What is the most important ROS, and how is it formed?

Answer 26

Myeloperoxidase (MPO) combines with a halide and forms HOCl, which is the most important ROS

Question 27

What is a NET?

Answer 27

Neutrophil extracellular trap: sacrifices its nucleus by casting its chromatin laden with killer granules out of the cell as a net to trap bacteria and fungi

Question 28

Half life of monocytes

Answer 28

Circulate for 16 hours (largest leukocyte in the blood)

Question 29

Interleukins involved in “cleanup” of the inflammatory response

Answer 29

IL-10 and TGF-beta; establish the correct milieu for appropriate healing and wound repair

Question 30

Control of acute inflammation

Answer 30

• Controlled mostly by macrophages

- Also by decreased activation of TLRs

Question 31

Least severe form of acute inflammation

Answer 31

Serous - protein-poor transudate from capillary to a space: peritoneal, pericardial, or pleural

Question 32

Intermediate morphology of acute inflammation

Answer 32

Fibrinous - fluid with larger molecules dominated by fibrinogen which converts to fibrin and potential scarring

Question 33

Severe morphology of acute inflammation

Answer 33

Suppurative/abscess - protein-rich fluid with inflammatory cell, alive and dead necrotic debris

Question 34

Example of serous inflammation

Answer 34

Blister

Question 35

Example of fibrinous inflammation

Answer 35

Pericarditis; deposits fibrin on the pericardium

Question 36

Example of suppurative inflammation

Answer 36

Bacterial abscesses in the lung in bronchopneumonia

Question 37

Ulcerative inflammation

Answer 37

Underlying inflammation causes excavation of a mucosal or skin surface