Chronic Inflammation & Repair 2

Question 1

Describe the outcomes of tissue injury.

Answer 1

Question 2

Describe the 3 different phases of wound healing.

Answer 2

1. Inflammation (1-4d)
   -hemostasis, acut inflam
   -neutrophils & macrophages remove dead tissue & exudate
2. Proliferation (3 wks)
   -macrophages
   -granulation tissue
   -fibroplasia & angiogenesis
3. Maturation (2 yrs)
   -wound healed via scar (fibrosis)
   -deposition of collagen by fibroblasts
   -immature -> mature CT

Question 3

Describe granulation tissue.

Answer 3

-tissue made during repair of wounds
>fills tissue defect & provides support for wound repair & remodeling
-grossly: pink/red, soft tissue, bleeds easily, granular
-histology: fibroblasts & angiogenesis
>fibroblasts & endothelial cells proliferate thru fibrin gel gen during inflam resp -> forms granulation tissue

Blood vessels vertical & fibroblasts horizontal (scaffolding)

Question 4

Describe examples of granulation tissue.

Answer 4

Question 5

Describe fibrous CT/scar tissue.

Question 6

Describe the difference between granuloma VS granulation tissue.

Answer 6

1. Granuloma
   -nodular
   -macrophage
   -chronic inflam resp
2. Granulation tissue
   -prolif of fibroblasts & capillaries
   -repair process

Question 7

Describe the difference between fibrin & fibrosis.

Answer 7

1. Fibrin
   -protein gen when plasma fibrogen (acute phase protein made by liver by inflam cytokines) involved in coagulation pathway
   -deposited outside vessels
   -damaged vessel = framework for growth of granulation tissue
2. Fibrosis
   -laying down fibrous tissue
   -formation of granulation tissue = early ex of fibrosis
   -adv & mature process
   >less capillary & more dense orderly collagen

Fibrosis

Question 8

Describe in wound healing/repair regeneration VS repair.

Answer 8

success determined by process of first of second intention healing
-regen = necrotic tissue replaced by tissue similar to original
-repair = injured tissue replaces by fibrous tissue

Question 9

Describe first intention healing.

Answer 9

-simple, uncomplicated healing
-rapid
-wound has opposed edges
>ex. Clean, uninfected surgical wounds (goal for surgeon repair of incision sites)
-2-3d = hemorrhage & cell debris removed by macs
>angiogenesis
>ECM syn to fill gaps between opposed tissue edges
-little trace of wound
>weeks -> stable interconnection replaced by collagen fibers
-continual maturation = skin has normal tensile strength after wound healing

Question 10

Describe second intention healing.

Answer 10

-complicated
-wounds have sep edges
>large defect to fill or septic wounds w foreign bodies
-fibrous CT fills defect
>delay/prevent migration of epi cells
-granulation tissue form reduced tensile strength
-intense inflam, lg amounts of granulation tissue & wound contraction in healing

Question 11

Describe macrophages role in inflammation & wound repair.

Answer 11

-chronic inflam & wound healing
-TGFB = stim prolif & activation of fibroblasts -> deposit fibrous CT (collagen)

Question 12

Describe factors affecting tissue repair.

Answer 12

1. Systemic factors
   -nutrition
   -metabolic
   -circulatory
   -hormones
2. Local
   -infection
   -foreign bodies
   -mechanical factors
   -size, location, type of wound

Question 13

Describe labile cells.

Answer 13

high continuous replication
1. Surface epi: strat squamous skin, oral cavity, vag, cervix
2. Lining mucosa of all excretory ducts of glands of body
3. Columnar epi of GIT, uterus, Fallopian tubes
4. Transitional epi of urinary tract
5. Cells of spleen, lymphoid, hematopoietic tissue

Question 14

Describe stable cells.

Answer 14

low replication
1. Epi cell of liver, kidney, lung pancreas
2. Smooth muscle cells
3. Fibroblasts
4. Vascular endothelial cells

Question 15

Describe permanent cells.

Answer 15

no mitotic division
-neurons
-cardiac muscle cells

Question 16

Describe pathological aspects of wound repair.

Answer 16

1. Inadequate formation of granulation tissue
   A)wound dehiscence
   -inf
   -excessive activity
   B) ulceration
   -inadequate vascularization during healing
2. Excessive formation of granulation tissue & fibrosis
   -hypertrophic scars
   >proud flesh in horses
   >keloid in humans

Question 17

Describe the summary!

Answer 17

1. Granulation tissue = new tissue, repair wound, pink, soft, bleed easy, fibroblasts & fibrocytes (fibroplasia), young blood vessels
2. Tissue healing & scar formation
   -angiogenesis, fibroblast prolif & fibrosis
3. Healing by first intention = simple, opposed edges, uninfected surgical wounds
4. Healing by second intention = complicated, separated edges, lg defect, granulation tissue forms, replaced by fibrous tissue
5. Factors influence wound healing:
   A) systemic: nutrition, metabolism, circ, hormones
   B) local: inf, mech, foreign body, size, location, type of wound
6. Pathological consequence of chronic inflam & inadequate healing
   A) inadequate granulation tissue (dehiscence, ulceration)
   B) excessive granulation tissue (keloid)