02/23a Inflammation I

Question 1

What is inflammation?

Answer 1

Body’s response to injury, including infection

Question 2

What are the functions of inflammation?

Answer 2

To destroy, dilute, or wall off the injurious agent

To initiate the repair process

Question 3

Inflammation is fundamentally a protective response. In what specific examples is inflammation harmful?

Answer 3

Hypersensitivity reactions - insect bites, drugs, etc.
Chronic diseases such as arthritis and atherosclerosis
Disfiguring scars
Visceral adhesions

Question 4

What are the two components of an inflammatory response?

Answer 4

Vascular reaction

Cellular reaction

Question 5

How is inflammation initiated?

Answer 5

By chemical mediators that are derived from plasma proteins or from cells

Question 6

What are the three types of inflammation?

Answer 6

Acute
Chronic
Granulomatous

Question 7

What are the major characteristics of acute inflammation (cells, time, etc.)

Answer 7

Short duration
Mainly neutrophils
Causes edema

Question 8

What are the major characteristics of chronic inflammation?

Answer 8

Longer duration
Mainly lymphocytes and macrophages
Causes fibrosis and angiogenesis

Question 9

What are the major characteristics of granulomatous inflammation?

Answer 9

A type of chronic inflammation

Predominance of epithelioid cells (activated macrophages) and possible multinucleated giant cells

Question 10

What are the three major components of acute inflammation?

Answer 10

1) Increase in blood flow
2) Edema resulting from vasodilation and protein leakage
3) Leukocyte migration from circulation to focus of injury

Question 11

What can stimulate acute inflammation?

Answer 11

Infections
Trauma
Physical or chemical agents
Foreign bodies
Immune reactions

Question 12

What are five mechanisms of increasing vascular permeability?

Answer 12

1) Formation of gaps between cells due to endothelial contraction - most common, fast and short-lived
2) Direct injury to the vessel - fast, may be long-lived
3) Leukocyte-dependent injury - release of factors that damage vessel walls, often happens in the lungs
4) Increased transcytosis (exocytosis of fluid)
5) New blood vessel formation - new vessels tend to be leaky, can be significant in the eye

Question 13

What is extravasation?

Answer 13

Deliver of leukocytes from a vessel lumen to the interstitium

Question 14

What is diapedesis?

Answer 14

Migration of a leukocyte across the endothelium

Question 15

What is chemotaxis?

Answer 15

Migration of a leukocyte into the interstitial fluid

Question 16

Describe the timeline of leukocyte emigration - which cells predominate at what time after injury?

Answer 16

6-24 hours after injury - neutrophils predominate

24-48 hours after injury - monocytes predominate

Question 17

What are the four possible outcomes of acute inflammation?

Answer 17

1) Complete resolution of the infection/injury
2) Abscess formation
3) Fibrosis - occurs after substantial tissue destruction, in tissues that cannot regenerate, or after abundant fibrin exudation
4) Progression into chronic inflammation

Question 18

In what cases might your body skip acute inflammation and progress directly to chronic inflammation?

Answer 18

Certain viral infections

Question 19

What are four morphological patterns seen in acute inflammation?

Answer 19

Serous inflammation
Fibrinous inflammation
Suppurative inflammation
Ulcers

Question 20

What is serous inflammation?

Answer 20

An outpouring of thin fluid (burn blisters)

Question 21

What is fibrous inflammation?

Answer 21

Leakage of fibrin into body cavities that may lead to scar tissue (adhesions)

Question 22

What is suppurative or purulent inflammation?

Answer 22

Formation of pus or purulent exudate, a mixture of neutrophils, debris, and edema fluid (abscess)

Question 23

What is an ulcer?

Answer 23

A local defect on the surface of an organ or tissue produced by sloughing of inflammatory necrotic tissue

Question 24

What are the systemic manifestations of acute inflammation?

Answer 24

Endocrine and metabolic
Fever
Autonomic
Behavioral
Leukocytosis or leukopenia

Question 25

What is the purpose of a fever?

Answer 25

Improves efficiency of leukocyte killing | Impairs replication of many offending organisms

Question 26

What are the endocrine and metabolic manifestations of acute inflammation?

Answer 26

Secretion of acute phase proteins by the liver Increased production of glucocorticoids in response to stress Decreased secretion of vasopressin, resulting in body fluid reduction

Question 27

What are the autonomic manifestations of acute inflammation?

Answer 27

Redirection of blood flow from skin to deep vascular beds Increased pulse and blood pressure Decreased sweating to preserve fluid volume

Question 28

What are some behavioral manifestations of acute inflammation?

Answer 28

``` Shivering Chills Anorexia Somnolence Malaise ```

Question 29

What is leukocytosis? What infections cause it?

Answer 29

Increased leukocyte count Bacterial infections can cause neutrophilia Certain viral infections can cause lymphocytosis Parasites, asthma, and hay fever can cause eosinophilia

Question 30

What is leukopenia? What infections cause it?

Answer 30

Decreased leukocyte count | Can be caused by typhoid fever, some viruses, rickettsiae, and protozoa

Question 31

What types of infections and injuries can cause chronic inflammation?

Answer 31

Persistent infections such as syphilis and certain viruses, fungi, and parasites Exposure to toxic agents, which can be exogenous (silica dust) or endogenous (toxic plasma lipid components leading to atherosclerosis) Autoimmunity, as in cases of rheumatoid arthritis and systemic lupus erythematosis

Question 32

What are the histological features of chronic inflammation?

Answer 32

Infiltration with mononuclear cells (T cells, B cells, macrophages) Tissue destruction Healing by replacement of damaged tissue by fibrosis and angiogenesis

Question 33

What are the functions of macrophages in chronic inflammation?

Answer 33

Secrete biologically active products to engulf microbes and kill them, stimulate inflammation, and repair tissue

Question 34

What are the functions of lymphocytes in chronic inflammation?

Answer 34

Produce inflammatory mediators Participate in cell-mediated immune reactions Produce antibody (B cells)

Question 35

What are the functions of eosinophils in chronic inflammation?

Answer 35

Combat parasitic infections with toxic proteins contained in their granules Active in immune reactions mediated by IgE (such as allergies)

Question 36

What is the function of mast cells in chronic inflammation?

Answer 36

Release histamine and cytokines

Question 37

What is a granuloma?

Answer 37

A focal area of granulomatous inflammation

Question 38

What are the two types of granulomas?

Answer 38

Foreign body granuloma - forms when a foreign material is too large to be engulfed by a single macrophage Immune granulmoa - forms when insoluble or poorly soluble particles elicit a cell-mediated immune response