Exam 1: Healing and Repair

Question 1

when does repair start

Answer 1

pretty soon after inflammation does; and continues during and beyond inflammatory phase

Question 2

perfect restoration of function is dependent on

Answer 2

regeneration of lost cells by similar cells; and the orderly arrangement of these new cells in relation to preexisting cells (repair by regeneration)

Question 3

if the original cells cannot be replaced by their own kind then they are rpelaced by

Answer 3

other cell types (repair by replacement) usually by fibrous connective tissue

Question 4

if necrosis is extensive, even tissues that are capable of regenration are repalced by

Answer 4

fibrous connective tissue

Question 5

what are the steps in scar formation

Answer 5

angiongenesis
formation of granulation tissue
remodeling of connective tissue to produce stable fibrous scar

Question 6

angiogenesis

Answer 6

formation of new blood vessels, which supply nutrients and oxygen needed to support the repair process

Question 7

formation of granulation tissue

Answer 7

proliferation of fibroblasts and new thin-walled, delicate capillaries in a loose extracellular matrix, often with admixed inflammatory cells, mainly macrophages

Question 8

scar comprises

Answer 8

a cellular CT largely devoid of inflammatory cells and covered by an esentially normal epidermis

Question 9

dermal appendages destroyed in the line of the incision are

Answer 9

permanently lost

Question 10

granulation tissue

Answer 10

part of the repair process and consits of inflamed proliferating fibrous tissue

Question 11

granulomatous

Answer 11

inflammatory infiltrates characterized by macrophages

Question 12

major cytokine involved in fibrosis is

Answer 12

TGF-B

Question 13

platelet derived growth factor (PDGF) sources

Answer 13

platelets, macrophages, endothelium

Question 14

PDGF function

Answer 14

chemotactic for fibroblasts, macrophags, smooth muscle, mitogenic for fibroblasts

Question 15

transforming growth factor beta (TGFB) sources

Answer 15

platelets, t cells, macrophages

Question 16

TGFB function

Answer 16

chemotactic for fibroblasts, leukocytes, stimulates proliferation of fibroblasts, extracellular matrix

Question 17

fibroblast growth factor (FGF) sources

Answer 17

many cell types

Question 18

FGF function

Answer 18

stiulates angiogenesis, mitogenic for endothelium, smooth muscle, fibroblasts

Question 19

epidermal growth factor (EGF) sources

Answer 19

platelets, macrophages

Question 20

EGFf function

Answer 20

induces proliferation of epithelium, endothelium, fibroblasts, increases production of glycosaminoglycans

Question 21

insulin-like growth factors (igf) sources

Answer 21

fibroblasts, hepatocytes

Question 22

IGF function

Answer 22

mitogenic for fibroblasts

Question 23

IL-1 source

Answer 23

macrophages, endothelium

Question 24

IL-1 function

Answer 24

chemotacti for leukocytes, stimulates proliferatio of keratinocytes, fibroblasts, endothelium

Question 25

TNFa sources

Answer 25

macrophages

Question 26

TNFa funciton

Answer 26

mitogenic for fibroblasts; angiogenic

Question 27

IFNy source

Answer 27

lymphocytes

Question 28

IFNy function

Answer 28

inhibits fibrobast proliferation; inhibits collagen synthesis

Question 29

fibrosis most often refers to

Answer 29

abnormal deposition of collagen that occurs in internal organs in chronic diseases

Question 30

fibrosis is typically associated with

Answer 30

loss of tissue and may be responsible for substancial organ dysfunction and even organ failure, such a s in a cirrhotic liver or end-stage kidney

Question 31

when a fracture occurs, growth factors are released by macrophages and plateltes in the blood clot (hematoma) and start the

Answer 31

proliferation of cartilage and granulation tissue

Question 32

callus

Answer 32

refers to an unorganized meshwork of woven bone

Question 33

after months, there is modeling of the woven bone into

Answer 33

lamellar bone

Question 34

what are the most common complicationsof fracture healing

Answer 34

inadequate blood supply, instability, and infection

Question 35

what are the steps in bone healing

Answer 35

1. fragments displaced, soft tissue traumatized, bleeding, hematoma 2. proliferation of cartilage and granulation tissue 3. callus 4. modeling of woven bone into laellar bone

Question 36

why is repair in CNS very limited

Answer 36

because mature neurons do not divide (neurons and processes are lost forever)

Question 37

after nervous tissue is gone, replacement by

Answer 37

glial cells (astrocytes) forming a glial scar

Question 38

in PNS injury to nerves may be followed by

Answer 38

regeneration if the nerve cell body remains

Question 39

myocardial cells are

Answer 39

permanent

Question 40

repair can only take place in myocardium by

Answer 40

fibrosis; which decreases myocardial contractility