Pathology Quiz 3 Topic 11

Front 1

What is the objective of healing and repair

Back 1

Return normal anatomical and functional integrity to injured tissue

Front 2

What is the process of healing and repair

Back 2

Regeneration - labile cells, stable cells, permanent cells
Replacement by fibrous tissue

Front 3

Side 2: What are labile cells
Side 3: What are some examples

Back 3

Continuously dividing cells - continue to proliferate throughout life, replacing cells continuously being destroyed; regeneration derived from stem cells

Hint 3

Epithelial cells - skin; oral cavity; reproductive, GI, respiratory, and urinary tracts, ducts
Bone marrow/hematopoietic tissues

Front 4

Side 2: What are Stable cells
Side 3: What are some examples

Back 4

Quiescent cells - normally demonstrate low level of replication; can undergo rapid division in response to stimuli and thus have potential to regenerate injured tissue

Hint 4

Parenchymal cells of all organs (liver, kidney, pancrease)
Mesenchymal cells (fibroblasts and smooth muscle)
Vascular endothelial cells

Front 5

What are the 5 requirements for regeneration by labile and stable cells

Back 5

Adequate blood supply
Viable connective tissue "scaffolding" or stroma
Basement membrane in parenchymal organs
Duct system to remove secretions of glandular origin
Precursor cells undergo division, motility, and differentiation

Front 6

Side 2: What are permanent cells
Side 3: What are some examples

Back 6

Nondividing cells - cells have left cell cycle and cannot divide in postnatal life

Hint 6

Neurons
Skeletal muscle - limited regenerative capacity
Heart muscle - Very limited, if any, regenerative capacity

Front 7

Side 2: When does healing by fibrous replacement take place
Side 3: What are the two forms of fibrous replacement

Back 7

When tissue damage is such that regeneration of injured tissue does not take place

Hint 7

Primary union or healing by first intention - clean (uninfected), sutured, surgical incision
Secondary union of healing by second intention - large surface wounds, infarcts, ulcers, abscesses

Front 8

Side 2: What takes place within the first 24 hours of first intention healing
Side 3: The first 3 days

Back 8

Neutrophils appear at edge of incision
Epidermis at edge of wound thickens due to mitotic activity of basal cells
Epithelial cells migrate along edges of wound, eventually fusing, midline, beneath scab surface

Hint 8

Neutrophils replaced by macrophages
Proliferation of young fibroblasts and capillary endothelial cells from wound edges (granulation tissue)
Epithelial proliferation continues

Front 9

Side 2: What takes place in the first 5 days of first intention healing
Side 3: Second week to months later

Back 9

Granulation tissue fills incisional space
maximal neovascularization and beginning collagen deposition
Epidermis returns to normal thickness

Hint 9

Wound site becomes less cellular and less vascular
Increasing deposition and remodeling of collagen
Tensile strength of wound increases but never reaches original tissue tensile strength

Front 10

What is healing by second intention

Back 10

Inflammatory reaction in wound site more intense due to more exudate and inflammatory debris that must be removed
Lost tissue replaced by granulation tissue
with time, there is substantial wound contraction

Front 11

What is neovascularization

Back 11

The proliferation of endothelial cells towards the surface of the wound forming capillaries with and without lument

Front 12

What is the name of contractile fibroblasts

Back 12

Myofibroblasts

Front 13

Side 2: What is responsible for the red, wet appearance on the surface of granulation tissue
Side 3: What is responsible for scab formation

Back 13

Inter endothelial junctions of developing capillaries are very leaky to fluids and cells

Hint 13

Drying of exudated serum and fibrin polymerization

Front 14

What happens during maturation of granulation tissue

Back 14

Vessels mature (less edema) and become aligned perpendicular to surface with fibroblasts and collagen aligned perpendicular to vessels
Aggregation of collagen into dense bands of fibrous tissue
Wound contraction (5-10% of original size)

Front 15

What factors influence wound healing

Back 15

Type, size, location
Blood supply
Infection
Nutritional status of animal
Movement

Front 16

What are proteoglycant

Back 16

First extracellular matrix component formed
Help in organization of extracellular matrix

Front 17

What property do elastic fibers have

Back 17

Recoil after stretching

Front 18

What is fibronectin

Back 18

Glycoprotein synthesized in liver
Bind to a variety of matrix proteins and cell surfaces, functioning to hold tissues together
Chemotactic for macrophages and fibroblasts

Front 19

Side 2: What are the two types of collagen most important for wound healing
Side 3: What are some properties of each

Back 19

Type I and Type III

Hint 19

Type I - Causes scars to be firm and infexible, stronger
Type III - deposited initially; replaced by Type I, more extensible

Front 20

Side 2: What vitamin is required for hydroxylation of proline in during procollagen synthesis
Side 3: What is the condition when there is a deficiency in this vitamin

Back 20

Vitamin C

Hint 20

Scurvy

Front 21

Side 2: What is the importance of copper in collagen synthesis
Side 3: What does a copper deficiency lead to

Back 21

Cross - linking of collagen molecules to form large fibrils
Copper deficiency leads to weak collagen

Hint 21

"steely wool" - lack of crimp, tensile strength, loss of pigment
"Swayback" in lambs - enzootic ataxia, CNS maldevelopment, bone fragility

Front 22

What results from defects in collagen metabolism

Back 22

Skin fragility, hyperextensibility, laxity

Front 23

Side 2: What factor breaks down collagen
Side 3: From what cells is it secreted

Back 23

Collagenases

Hint 23

Fibroblasts, macrophages, endothelial and epithelial cells

Front 24

What factors help maintain balance between collagen synthesis and degradation

Back 24

Collagenase inhibitors