Inflammation

Question 1

Ten Generalities about the Inflammatory Response

Answer 1

1.
It is a process, not a thing.
2.
It occurs only in living tissue.
3.
It is a series of events overlapping into a continuum.
4.
It is a response and therefore requires initiation by some kind of stimulus.
5.
The response can be more harmful than the initiating stimulus.
6.
It is survival oriented and does not object to scarring as an end result.
7.
It is fairly stereotyped irrespective of the initiating stimulus.
8.
It has most of its components in the blood, whereas injury is always in the tissues.
9.
It is a carefully coordinated defense mechanism essential to life.
10.
It is complicated, but understandable.

Question 2

is the vascular and cellular responses of living tissue to injury.

It is the reaction of the living tissue to injury, which comprises a series of changes in the terminal vascular bed, in the blood, and in the connective tissues that tend to eliminate the offending irritant and to repair the damaged tissue.

Inflammation consists of a series of complex reactions by vascular and connective tissue
elements to a tissue injury.

Answer 2

Inflammation

Question 3

A definition of inflammation is complicated because systemic effects that include malaise,
fever, leukocytosis metabolic disturbances and shock may accompany the local vascular and tissue reactions.
Inflammation is the directed tissue response to noxious and injurious external and internal
stimuli.

Question 4

– (the toxic and injurious substances produced by microbes).
Included are bacteria, viruses, protozoa, fungi and parasitic metazoa.

Answer 4

Pathogenic microorganisms

Question 5

– toxins, free radicals, drugs, acids, alkalis etc.

Answer 5

Chemical injuries

Question 6

The following are general etiologic agents of inflammation.
1.
Pathogenic microorganisms – (the toxic and injurious substances produced by microbes).
Included are bacteria, viruses, protozoa, fungi and parasitic metazoa.
2.
Chemical injuries – toxins, free radicals, drugs, acids, alkalis etc.
3.
Mechanical and thermal injuries (physical) – burns, heat, irradiation, excessive cold as
well as trauma, blows, lacerations, pressure.
4.
Immune reactions – antigen-antibody complexes, hypersensitivity reactions, immune
depositions etc.

Question 7

Functions of the Inflammatory Response
To minimize the effect of an irritant the injured tissue is the goal of inflammatory response. This
is done by accumulation of fluids and cells in the injured area. The overall plan for this fluids and
cells is to:

Answer 7

1.to dilute
2.to localize
3.to destroy
4.to remove

Question 8

Advantages and Disadvantages of Inflammation
ADVANTAGES
1.
It protects the surrounding healthy tissue by localizing and isolating the injured or
infected tissue.
2.
Inflammatory processes neutralize and inactivate toxins.
3.
It destroys and inhibits the growth of pathogenic microorganisms.
4.
It readies the injured area for healing and repair by eliminating damaged tissue and
necrotic cell debris.
DISADVANTAGES
1.
It can result to excessive scar tissue formation as with keloids, contractures, adhesions etc.
2.
Varying degrees of disabilities as result of pain and swelling.
3.
Tissue compression, vessel rupture and hemorrhage.
4.
Formation of cavity, sinus and fistula.
5.
Aggravates inflammation by destruction of surrounding intact tissues.
6.
Development of inflammatory diseases such as glomerulonephritis, hypersensitivity illness.

Question 9

INFLAMMATION Overview:
• Inflammation is the vascular and cellular responses of living tissue to
injury. Inflammation is the body’s response to tissue injury, infection, or
harmful stimuli.
• Purpose: It aims to eliminate the initial cause of cell injury, clear out damaged
cells and tissues, and establish a repair process.

Question 10

Vascular Changes:

Answer 10

o Vasodilation: Increases blood flow to the affected area, causing redness
and heat.
o Increased Permeability: Allows proteins and leukocytes to leave the
bloodstream and enter the tissue, leading to swelling.

Question 11

Cellular Response:

Answer 11

o Leukocyte Recruitment: White blood cells (leukocytes) migrate to the
site of injury.
o Phagocytosis: Leukocytes engulf and digest pathogens and debris.

Question 12

Chemical Mediators:

Answer 12

o Cytokines and Chemokines: Signaling molecules that regulate the
inflammatory response.
o Acute Phase Proteins: Produced by the liver, these proteins enhance the
inflammatory response.

Question 13

Clinical Signs of Inflammation:

Answer 13

o Redness (Rubor)
o Heat (Calor)
o Swelling (Tumor)
o Pain (Dolor)
o Loss of Function (Functio Laesa)

Question 14

Outcomes of Inflammation:

Answer 14

o Resolution: Complete healing without any residual damage.
o Chronic Inflammation: Prolonged inflammation leading to tissue
damage and fibrosis.
o Abscess Formation: Collection of pus due to infection.
o Scarring: Replacement of normal tissue with fibrous tissue.

Question 15

Cardinal Signs of Inflammation
Cornelius Celsus (30BC to 30 AD) formulated the 4 cardinal features of inflammation:
1. rubor
-
REDNESS
2. tumor
-
SWELLING
3. calor
-
HEAT
4. dolor
-
PAIN
Rudolf Virchow (1821-1902), the father of modern pathology added:
5. functio laesa
LOSS OF FUNCTION

Question 16

is caused by vasodilatation.

Answer 16

Redness

Question 17

results mainly from fluid exudates accumulation
consequent to increased vascular permeability

Answer 17

Swelling

Question 18

sensation of ____ is attributable to rapid
inflow of warm blood through dilated vessels in an inflamed area

Answer 18

heat

Question 19

Pain can be due to
distension/compression of tissue and factors such as release of vasoactive chemicals i.e. kinins,
histamines, metabolites and bradykinin contribute to pain.

Question 20

added to prevent
using the part that hurts.

Answer 20

Loss of function

Question 21

. The escape of fluid and blood cells from the vascular system into the interstitial tissue
or body cavities.

Answer 21

Exudation

Question 22

. An inflammatory extravascular fluid that has a high protein concentration, much
cellular debris, and a specific gravity above 1.020

Answer 22

Exudate

Question 23

. A fluid with low protein content and a specific gravity of less than 1.012. It is
essentially an ultra filtrate of blood plasma and results from hydrostatic imbalance across the
vascular endothelium.

Answer 23

Transudate

Question 24

Development of Transudates and Exudates. A, Normal hydrostatic pressare (blue arrow) can lead to the outflow of thad, but this is counter balanced by the mean colloid osmotic pressure (green arrow), which attracts fluid to the vascular lumen, therefore the net flow of fluid acrow the vascular bed is minimal. B. A transudate forms when fluid leaks out because of increased hydrostatic pressure of decreased cumotic pressure along with increased permeability across the endothelial cell layer. C. An exudate forms in and damage to the endothelial laver inflammation because vascular permeability increases result of of increased interendothelial spaces

Question 25

. Denotes an excess of fluid in the interstitial tissue or serous cavities; it can be either an exudates or a transudate.

Answer 25

Edema

Question 26

– also known as the polymorphonuclear cells (PMN’s) or pus cells, are cells of cute inflammatory response. They are the first to arrive at the site of inflammation. Neutrophils are phagocytic cell that subsequently destroys invading microbes by releasing lytic lysosomal enzymes and formation of chemotactic factors. The lysosomal enzymes (present in the granules):

Answer 26

Neutrophils

Question 27

Neutrophils are phagocytic cell that subsequently destroys invading microbes by releasing lytic lysosomal enzymes and formation of chemotactic factors. The lysosomal enzymes (present in the granules):

Answer 27

a) Myeloperoxidase b) Acid hydrolases c) Lysozome (muramidase) d) Cationic proteins

Question 28

– usually prominent in allergic reactions and parasitic migrations. Lysosomal granules contains enzyme that degrade and neutralizes the action of potent vasoactive chemicals e.g. histaminase degrades/inactivates histamines; arylsulfatase B, which inactivates SRS-A. eosinophils are phagocytic.

Answer 28

Eosinophils

Question 29

– the least numerous of the granulocytes, basophils share common properties with mast cells by their ability to secrete or to release vasoactive amines/chemicals. The granules contain histamines, heparin and SRS-A. Basophils are non-phagocytic.

Answer 29

Basophils

Question 30

Monocytes – are peripheral blood phagocytes. Once in migrated in the tissues, monocytes become part of the tissue macrophage. Monocytes are phagocytic and are involved in immune response as an antigen-presenting cell.

Question 31

Lymphocytes – Lymphocytes are found in the tissues in all types of inflammation, especially after the acute ingress of neutrophils. All lymphocytes are derived from bone marrow stem cells and differentiate into lymphocytes in the primary lymphoid organs (i.e., thymus and bone marrow). From there lymphocytes seed to secondary lymphoid organs i.e. lymph nodes, spleen, tonsils, Peyer’s patches etc. They are the cells involved in both the cell mediated (CMI) and humoral immune (HI) responses. Three types of lymphocytes are currently recognized the first two are non-phagocytic. a.) T lymphocytes – thymic lymphocytes; found in the paracortical areas of lymph nodes; comprise about 70% of peripheral lymphocytes; involved in CMI. T cell surface marker = CD or cellular differentiation or T i Helper T cells – CD4 or T4; aids in humoral immunity ii Suppressor and cytotoxic T cells –CD8 or T8

Question 32

– bursua derived lymphocytes; involved in HI. B cells are found in the paracotical areas of the lymph nodes and in the germinal centers of lymphoid follicles.

Answer 32

B lymphocytes

Question 33

– are lymphocytes that are nondefinable by either B or T cell criteria. They are phagocytcic and nonspecific

Answer 33

Null or natural killer (NK) cells

Question 34

__________ – formed by a process of maturation and division of B lymphocytes into two distinct cells: __________ and ______ Their presence indicates a humoral response. Surface of plasma cells contain specific class of immunoglobulin or antibodies.

Answer 34

Plasma cells memory cells and plasma cells.

Question 35

Macrophages – are tissue phagocytes; depending on their location, macrophages are named accordingly: histiocytes - connective tissues Langerhans cells - skin von Kupffer cells - liver alveolar macrophages - lungs mesangial cells - kidneys microglial cells - brain spleen/lymph nodes - free and fixed macrophages pleura and peritoneum - macrophages Macrophages are important components of the immune system.

Question 36

- connective tissues

Answer 36

histiocytes

Question 37

- skin

Answer 37

Langerhans cells

Question 38

- liver

Answer 38

von Kupffer cells

Question 39

- lungs

Answer 39

alveolar macrophages

Question 40

- kidneys

Answer 40

mesangial cells

Question 41

brain

Answer 41

microglial cells -

Question 42

- free and fixed macrophages

Answer 42

spleen/lymph nodes

Question 43

- macrophages Macrophages are important components of the immune system.

Answer 43

pleura and peritoneum

Question 44

T cell activation a. ____^^__ “present” processed antigens to T cells in conjunction with _________________________________ molecules on the macrophage surface. These steps are required in the sensitization and activation of T cells. b. Macrophages releases _____________, a substance that stimulates sensitized T cell activation to ILL-2. The latter allows full T cell activation to proceed to and causes the proliferation of various T cell subsets.

Answer 44

Macrophages major histocompatibility complex (MHC) interleukin-1 (IL-1)

Question 45

Macrophage activation a. T cells, once activated, cause the mobilization and metabolic activation of macrophages by releasing various lymphokines. b. The activation of macrophages is immunologically specific. c. Activated macrophages prolong the inflammatory process and the cause tissue destruction by releasing their highly irritative enzymes. The process also has a protective function, thereby amplifying immune response.

Question 46

B cell activation a.B cell activation requires _____, which is secreted by macrophages (and some other APC’s or antigen presenting cells b. ________requires that antibody on the B cell surface match its specific antigen. Antigen on the macrophage surface serve this purpose. c. B cell activation is aided by the presence of _______.

Answer 46

IL-1 B cell activation helper inducer T cells

Question 47

Secretory functions of macrophages: .

Answer 47

1.Releases colony stimulating factor and tumor necrosis factor. 2. Release of alpha interferon, which aids in blocking viral replication. 3. Precursors of prostaglandins

Question 48

Healing and Repair:

Answer 48

1. Resorption by phagocytosis 2. Release of fibroblast proliferating factor 3. Epithelioid and Giant Cells – are formed from macrophages and are often found together in chronic lesions. Epithelioid cells resemble squamous epithelial cells and macrophages. Giant cells form by the fusion of the cytoplasm of macrophages.

Question 49

Two types of giant cells are recognized: a. Langhan’s Cells – giant cell with nuclei around the periphery b. Foreign body giant cells – the nuclei are arranged throughout the cell.

Question 50

– giant cell with nuclei around the periphery

Answer 50

Langhan’s Cells

Question 51

the nuclei are arranged throughout the cell.

Answer 51

Foreign body giant cells –

Question 52

are responsible for hemodynamic and vascular changes.

Answer 52

Vasoactive amines (i.e., histamines and serotonin)

Question 53

MEDIATORS OF INFLAMMATION A. Vasoactive amines (i.e., histamines and serotonin) are responsible for hemodynamic and vascular changes. 1. Histamine a. Source. Most of the body’s histamine is stored in the granules of mast cells. Also found in basophils and platelets. b. Release. Histamine is released by degranulation in response to various stimuli such as, physical factors (heat, cold, trauma, radiation), type 1 hypersensitivity reactions, C3a and C5a (referred to as anaphylatoxins), and cationic lysosomal proteins. c. Actions (1) Once released, histamine causes direct vascular effect. Some degree of vasoconstriction (which varies according to animal species) almost always occurs, followed by vasodilation (which is the stage of observable hyperemia). Histamine also causes an increase in the vascular permeability of small veins and venules. (2) Histamine also has been shown to be chemotactic for eosinophils. 2. Serotonin a. Source. Most of the body’s serotonin is stored in the gastrointestinal tract and central nervous system; a much smaller proportion exists in the dense granules of platelets.

Question 54

B. Plasma factors 1. The kinin system, when activated, leads to the formation of bradykinin. a. Generation of bradykinin. When plasma comes in contact with collagen, endotoxin, or basement membrane proteins, a there is an activation of clotting factor XII (Hageman factor). This is followed sequentially by kallikrein formation, which then converts high molecular-weight kininogen (HMWK) to bradykinin. 2. The complement system, an important mediator of the inflammatory process, contains 9 major plasma proteins, termed complement components. a. Activation of complement. Critical to the biologic action of the complement system is the activation, or cleavage, of complement component C3, which forms C3a. This can occur in two pathways. 1. In the classical pathway, circulating antigen-antibody complexes activate the system and by successive steps of cleavage and combination, generate complement components C3a and C5a. 2. In the alternate pathway, nonimmuologic stimuli (e.g. bacterial endotoxin) activate the system and lead to cleavage of C3. b.Actions • Both C3a and C5a are chemotactic for neutrophils and play an important role in the increased vascular permeability caused by histamine release from mast cells. • Following complement cascade activation (by either pathway), C5, C6, and C7 in combination also become chemotactic. • C5b through C9 (termed the membrane attack sequence) appears to be involved in injury to parenchymal cells. (C5b6789 – MEMBRANE ATTACK COMPLEX).

Question 55

, when activated, leads to the formation of bradykinin.

Answer 55

kinin system

Question 56

, when activated, leads to the formation of bradykinin.

Answer 56

kinin system

Question 57

The kinin system, when activated, leads to the formation of bradykinin. a. Generation of bradykinin. When plasma comes in contact with collagen, endotoxin, or basement membrane proteins, a there is an activation of clotting __________. This is followed sequentially by ______ formation, which then converts high molecular-weight kininogen (HMWK) to______// .

Answer 57

factor XII (Hageman factor) kallikrein bradykinin

Question 58

The________ , an important mediator of the inflammatory process, contains 9 major plasma proteins, termed complement components.

Answer 58

complement system

Question 59

Activation of complement. Critical to the biologic action of the complement system is the activation, or cleavage, of complement component C3, which forms C3a. This can occur in two pathways