inflammatory process

Question 1

cell characteristics

Answer 1

cells tend to preserve their environment to maintain homeostasis (body wants to go back to normal ASAP). Physiologic stress or pathologic stimuli cause cells to undergo adaptation and find a new steady state to preserve viability

Question 2

physiologic stress

Answer 2

stimulation of cells to do something different so cells begin to change. ex. lifting weights at the gym

Question 3

pathologic stimuli

Answer 3

rupturing of cells from too much stress ex. bowed tendon

Question 4

atrophy

Answer 4

decrease in cell size, but cells are still there

Question 5

hypertrophy

Answer 5

increase in cell size by increasing exercise or use

Question 6

hyperplasia

Answer 6

increase in cell number. May be caused by pregnancy (in uterus/udder) or cancer (tumor)

Question 7

metaplasia

Answer 7

change in cell type, may change back to original cell type. ex. cigarette smokers (normal cells in trachea have cilia but smokers do not have ciliated cells because they are more resistant to smoke)

Question 8

is injury reversible?

Answer 8

injury can be reversible, but with persistent or severe stress (ex. broken leg), injury is irreversible (results in cell death)

Question 9

Necrosis

Answer 9

loss of blood supply or exposure to toxins, cellular swelling, protein denaturation and tissue dysfunction results

Question 10

apoptosis

Answer 10

programmed cell death, dead cells are removed with minimal disruption of the surrounding tissue

Question 11

Causes of Cell Injury

Answer 11

1. oxygen deprevation (hypoxia) 2. chemical agents 3. infectious agents 4. genetic defects 5.immunologic reactions 6. nutritional imbalance 7. physical agents 8. aging

Question 12

ischemia

Answer 12

oxygen deprivation, loss of blood supply in tissue due to impeded arterial flow or reduced venous drainage ex. cut, atheriosclerosis, embolism

Question 13

inadequate oxygenation

Answer 13

type of oxygen deprevation, ex. pneumonia and emphysema

Question 14

reduced O2 carrying capacity of blood

Answer 14

ex. anemia, loss of red blood cells

Question 15

chemical agents

Answer 15

any chemical substance can cause cell injury (even salt and water). ethanol causes liver injury that is reversible at first but chronic ethanol use will lead to irreversible injury (liver exhaustion=cerosis)

Question 16

infectious agent

Answer 16

ex. virus, bacteria, worms, fungi, protozoan

Question 17

genetic defects

Answer 17

may result in pathologic changes ex. lethal white

Question 18

immunologic reactions

Answer 18

anaphylactic shock is classical example of an exaggerated immune response, auto-immune disease which is loss of self-tolerance (lupus, rheumatoid arthritis)

Question 19

anaphylactic shock

Answer 19

disregulated allergy causing an exaggerated immune response (causes swelling in throat, asphyxiation and death)

Question 20

nutritional imbalance

Answer 20

malnourishment or obesity

Question 21

physical agents

Answer 21

trauma (cuts, bruises, concussions ect.), burns, cold (frostbite)

Question 22

aging

Answer 22

the body becomes exhausted, repeated trauma, imperfect restoration of structure or function, cellular senescence

Question 23

what does response to injurious stimuli depend on?

Answer 23

type of injury, duration and severity

Question 24

what do consequences of injury depend on?

Answer 24

adaptability and genetic makeup (ex. cats heal faster than dogs) of the injured cell. ex. skeletal muscle can withstand 2-3 hours of ischemia w/o irreversible injury while the cardiac muscle can only tolerate 20-30 mins and the brain can only tolerate 3-4 mins

Question 25

inflammation

Answer 25

a protective response intended to eliminate the initial cause of cell injury as well as the necrotic (dead) cells and tissues resulting from the original insult, heals and reconstitutes the site of injury, interwoven with the repair process, helps clear infection and makes would healing possible but may cause harm

Question 26

acute inflammation

Answer 26

immediate and early response to injury, designed to deliver leukocytes to the site of injury

Question 27

leukocytes (white blood cells)

Answer 27

clear any invading microbes and begin the process of cleaning necrotic tissue

Question 28

two components of acute inflammation

Answer 28

vascular changes (vasodilation to increase blood flow) and cellular events (cellular recruitment and activation, leukocytes migrate)

Question 29

5 classical signs of acute inflammation

Answer 29

heat (area becomes hot to the touch, fever, caused by increased blood flow), redness (caused by increased blood flow), swelling (caused by leaky blood vessels allowing WBCs to enter the area), pain (caused by the inflammatory cells) and loss of function (not same as loss of movement)

Question 30

Neutrophils

Answer 30

first responders to bacterial and fungal infections, form pus

Question 31

eosinophils

Answer 31

deal with parasitic infection

Question 32

basophils

Answer 32

granulate, responsible for allergenic and antigen response, releases histamine

Question 33

lymphocytes

Answer 33

common in the lymphatic system, B cells make antibodies (cells that have memory)

Question 34

monocytes

Answer 34

perform phagocytosis

Question 35

vascular changes

Answer 35

1. initial vasoconstriction (seconds) to stop bleeding, platelet aggregation,blood coagulation->clot 2. vasodilation (responsible for redness and heat in inflamed area, caused by histamine release), brings in leukocytes 3. increase vascular permeability-protein rich fluid in extravascular tissue (we see edema or swelling). blood becomes more viscous and circulation slows down

Question 36

cellular changes

Answer 36

1. leukocytes (neutrophils) will transmigrate through intercellular junctions to the extracellular matrix 2. leukocytes will release chemical mediators that keep inflammation going ex. histamine, cytokines, leukotrienes, prostaglandins. these recruit more leukocytes to the area 3. phagocytosis: leukocytes will ingest (engulfment) injurous particle. Serves to both kill bacteria/virus and also to clean up dead cells

Question 37

outcome of acute inflammation

Answer 37

resolution, scarring/fibrosis, chronic inflammation

Question 38

resolution

Answer 38

when injury is limited or short lived, tissue is capable of replacing any irreversibly dead cell with new perfect and functional cells

Question 39

scarring/fibrosis

Answer 39

after substantial tissue damage or when injury occurs to the tissue that does not regenerate. in cases of abscess formation (bacteria, neutrophils, dead cells->pus). the only outcome is scarring

Question 40

chronic inflammation

Answer 40

persistant viral or bacterial infection, may be caused by debris in wound, wound constantly being reopened, compromised immune system. may lead to complete regeneration or fibrosis, use of anti-inflammatory agents are necessary

Question 41

angiogenesis

Answer 41

the creation of new blood vessels and cells, too many new blood vessels may be created that prevents blood from flowing to the area

Question 42

Extracellular Matrix (ECM)

Answer 42

critically regulates growth, movement and differentiation of cells, aids in mechanical support, determination of cell orientation, control of growth, organized regeneration of tissues

Question 43

components of the ECM

Answer 43

collagen (confer tensile strength, adds elasticity to new cells, primarily located in tendons, skin etc.), elastin (recoil and return to baseline structure), glycosaminoglycans and hyaluronan (highly hydrated compressible gels that confer resilience and lubrication)

Question 44

repair by connective tissue

Answer 44

if severe or persistent tissue injury occurs, the repair occurs by replacement of what should be normally functioning cells with connective tissue. granulation tissue (proud flesh) is formed. horses are prone to exuberant granulation tissue formation which impedes healing of wounds

Question 45

granulation tissue

Answer 45

angiogenesis, fibroblasts, loose ECM. Pink in color, soft and granular-looking tissue. highly populated with macrophages which clear debris and allow for fibroblast proliferation and ECM production. Becomes fibrotic tissue.

Question 46

wound healing

Answer 46

very organized event, specialized cells first clean the injured site and progressively built the scaffolding to fill in any resulting defect

Question 47

first intention wound healing

Answer 47

occurs with minor or precise injury ex. clean, uninfected surgical incision approximated by sutures. cells are regenerated, they maintain normal function and scar is minimal

Question 48

second intention wound healing

Answer 48

open wound, abscess, ulcerations. Normal architecture is not achieved, extensive ingrowth of granulation tissue, fibrotic scar formation is the result

Question 49

wound strength

Answer 49

carefully sutured wounds have 70% of normal strength of unwounded tissue. when suture is removed, wound strength is only about 10%, by the end of 3 months wound strength is about 70-80%