Tissue Repair

Question 1

example of Intact physical barriers

Answer 1

the skin and mucous membranes, cilia, and the strong acid produced by stomach glands

Question 2

these intact physical barriers are exerted at what level

Answer 2

local tissue level

Question 3

When tissue injury does occur,

it stimulates the body’s what

Answer 3

inflammatory and immune response

Question 4

when does the healing process begin

Answer 4

almost immediately

Question 5

Inflammation

Answer 5

is a generalized (nonspecific) body response that attempts to prevent further injury

Question 6

The immune response, in contrast,

is

Answer 6

extremely specific and mounts a vigorous attack
against recognized invaders, including bacteria,
viruses, and toxins.

Question 7

Tissue repair, or wound healing, occurs in

two major ways:

Answer 7

by regeneration and by fibrosis

Question 8

Regeneration

Answer 8

is the replacement of destroyed tissue by the same kind of cells

Question 9

fibrosis

Answer 9

involves repair by dense (fibrous) connective tissue, that is, by the formation of scar tissue.

Question 10

Which occurs depends on

Answer 10

(1) the type of tissue damaged

and (2) the severity of the injury

Question 11

Generally speaking, clean cuts (incisions) heal much more

Answer 11

successfully than ragged tears of the tissue

Question 12

Tissue injury sets a series of events into motion:

Answer 12

inflammation sets the stage
granulation tissue forms
Regeneration and fibrosis effect permanent repair

Question 13

injure tissue cells and other release what in the first stage

Answer 13

. Injured tissue cells and others release inflammatory chemicals

Question 14

the inflammatory chemicals do what

Answer 14

make the capillaries very permeable

Question 15

the capillaries being very permeable allow for what

Answer 15

This allows fluid rich in clotting proteins and other
substances to seep into the injured area from
the bloodstream

Question 16

Then leaked clotting proteins

construct a what

Answer 16

clot

Question 17

what does a clot do

Answer 17

stops the loss of blood, holds the edges of the wound together, and walls off the injured area, preventing bacteria or other harmful substances from spreading to
surrounding tissues.

Question 18

Where the clot is exposed

to air

Answer 18

it quickly dries and hardens, forming a

scab.

Question 19

what is Granulation tissue

Answer 19

is a delicate pink tissue composed largely of new capillaries that grow into the damaged area from undamaged blood vessels nearby.

Question 20

describe these capillaries in granulation tissue

Answer 20

These capillaries are fragile and
bleed freely, as when a scab is picked away
from a skin wound.

Question 21

Granulation tissue also

contains what

Answer 21

phagocytes that eventually dispose
of the blood clot and connective tissue cells
(fibroblasts) that produce the building blocks
of collagen fibers (scar tissue) to permanently
bridge the gap

Question 22

As the surface epithelium begins

to regenerate, it makes its way across the

Answer 22

granulation tissue just beneath the scab

Question 23

when the scab detaches what’s the final result

Answer 23

fully regenerated surface epithelium that covers an underlying area of fibrosis (the scar).
The scar is either invisible or visible as a thin
white line, depending on the severity of the
wound

Question 24

the scar is a

Answer 24

white line depending on the severity of the

wound. it can visible or invisible

Question 25

Epithelial tissues such as

the skin epidermis and mucous membranes regenerate

Answer 25

beautifully

Question 26

most of the fibrous

connective tissues and bone regenerate

Answer 26

beautifully

Question 27

Skeletal muscle regenerate

Answer 27

poorly

Question 28

cardiac muscle and nervous tissue within the brain and spinal cord are
replaced largely by

Answer 28

scar tissue

Question 29

tissue repair requires what

Answer 29

cell division that is initiated by growth hormones released from the injured cells

Question 30

what does granulation tissue contain

Answer 30

1) capillaries that grow in from nearby areas,

2) proliferating fibroblasts that produce growth factors and new collagen fibers.

Question 31

what do macrophages do to the clot

Answer 31

they digest the clot

Question 32

what does granulation tissue become

Answer 32

a scar tissue

Question 33

explain how scar tissue is resistant to infection

Answer 33

because it produces bacteria-inhibiting substances

Question 34

In case of pure infection what happens in terms of tissue repair

Answer 34

(like a pimple or sore throat), healing occurs only by

regeneration. Usually, there is no clot formation or scarring

Question 35

examples of tissues that regenerate very well

Answer 35

Epithelial tissues, bone, areolar connective tissue, dense irregular connective tissue, and blood forming
tissue

Question 36

examples of tissues that have a moderate capacity for regeneration.

Answer 36

Smooth muscle and dense regular connective tissue

Question 37

examples of tissues that have a weak capacity of regeneration

Answer 37

Skeletal muscle and cartilage

Question 38

examples of tissues that have no functional regenerative capacity and so are replaced by scar tissue

Answer 38

Cardiac muscle and the brain and spinal cord tissues