Tissue Healing And Repair

Question 1

Body organs and structures contain two functional types of tissues:

Answer 1

1. Parenchyma

2. Stroma

Question 2

What is parenchyma? Stroma?

Answer 2

Parenchyma- functioning cells

Stroma - supporting connective tissue

Question 3

The primary objective of healing process is to :

Answer 3

“fill the gap” - restore the structural continuity of the injured part

Question 4

Secondary objective of healing process is :

Answer 4

Restore the functional continuity of the injured part

Question 5

Injured tissue heal by:

Answer 5

1. Resolution if tissue damage is minimal
2. Regeneration of parenchymal cells
3. Replacement with connective tissue

Question 6

The chemical mediators involved with the healing process are:

Answer 6

1. Chemo taxis and fibroblast recruitment

2. Proliferation of cells

Question 7

This occurs in response to mild injury (small scratch, superficial injuries)

Answer 7

Resolution (repair)

Question 8

Injured cells can _______ themselves if damage is minimal, or else are rapidly _____w/o much body interruption

Answer 8

Repair , replaced

Question 9

🔹leaves little/no evidence of injury- injured cells are replaced w/ same cells - restoration of original structure and function

Answer 9

Regeneration

Question 10

Ability to regenerate varies with cell type:

Answer 10

▫️labile cells - skin and mucous membranes
▫️stable cells - undergo mitosis as necessary
▫️permanent cells - amitotic

Question 11

Non- regenerated parenchymal cells are replaced by a _____ scar (process also called fibrosis) when: ___, ____

Answer 11

🔵 CT
▫️extensive tissue damage occurred
▫️cells are amitotic

Question 12

Wound healing and closure occur by ___ and ___ depending on the extent of tissue damage

Answer 12

Primary or secondary intention

Question 13

small wound e.g. sutured surgical incision or paper cut

Answer 13

Primary intention

Question 14

e.g. burns, large surface wounds - tissues have undergone greater loss of tissues and contamination

Answer 14

Secondary intention

Question 15

Tissue healing consists of three phases:

Answer 15

1. Inflammation
2. Proliferation (repair, regeneration, replacement)
3. Remodelling

Question 16

It begins at time of injury and is important for preparing the wound for healing

Answer 16

Phase 1 - inflammation

Question 17

allows plasma and blood components to leak into injured area and start the clotting process

Answer 17

Vascular changes

Question 18

Neutrophils are first to arrive, macrophages will follow - enter the area of injured tissue, digest and remove invading organisms, debris and other foreign matter

Answer 18

Cellular changes

Question 19

▫️Usually begins w/n 2 to 3 days of injury and may last as long as 3 was
▫️granulation tissue is formed during this period
▫️healing by 2ndary intention

Answer 19

Phase II - proliferative phase

Question 20

Produce collagen also produce growth factors to initiate angiogenesis

Answer 20

Fibroblasts (recruited by macrophages)

Question 21

▫️consists of new blood vessels, proliferating fibroblasts, and residual inflammatory cells
▫️functions as the foundation of the scar tissue

Answer 21

Granulation tissue

Question 22

▫️Scar tissue remodels by breaking down old collagen (collagenase) and synthesizing new collagen (by fibroblasts) - increase tensile strength

Answer 22

Phase III - remodelling phase

Question 23

Injuries that heal by 2ndary intention undergo ________

Answer 23

Wound contraction