Healing

Question 1

What are the four stages of wound healing

Answer 1

1. Haemostasis
2. Inflammation
3. Proliferation
4. Remodelling

Question 2

When does haemostasis occur?

Answer 2

It occurs as soon as the wound opens

Question 3

What is a vasospasm?

Answer 3

narrowing of the arteries caused by persistent contraction

Question 4

What activates the platelets

Answer 4

The platelets are activated by exposed collagen from damaged vessels

Question 5

What is the consequence of platelets being activated?

Answer 5

• They promote vasoconstriction
• They initiate the formation of a platelet plug
• They start vessel healing

Question 6

When is acute inflammation fully established?

Answer 6

24 hours after injury

Question 7

How long can acute inflammation last?

Answer 7

Up to 96 hours if not disrupted

Question 8

What are some of the cardinal signs of inflammation that can be observed?

Answer 8

• Redness
• Swelling
• Heat
• Pain
• Loss of function

Question 9

What are some of the functions of neutrophils and macrophages during acute inflammation?

Answer 9

• They establish a microenvironment for the proliferation/granulation stage
• They are essential for wound healing (excessive can reduce healing)
• remove cell debris
• release cytokines for chemotaxis which helps to enhance angiogenesis

Question 10

What is angiogenesis?

Answer 10

The production of new endothelium

Question 11

What is epithelialisation?

Answer 11

The generation of new epithelium

Question 12

What is fibroplasia/ Desmoplasia?

Answer 12

The generation of new connective tissue stroma

Question 13

What three things make up the proliferation stage?

Answer 13

1. Angiogenesis
2. Epithelialisation
3. Fibroplasia/ Desmoplasia

Question 14

How long can the remodelling stage last for?

Answer 14

It begins 3-4 weeks after injury if earlier stages are complete
But can last for 2 years

Question 15

What occurs during the remodelling stage?

Answer 15

• Replacement of new connective tissue
• Removal of damaged connective tissue

to attempt to return the organ back to its function/ functional capacity

Question 16

Name 4 things that can cause impaired wound healing

Answer 16

1. Spontaneous causes
2. Wound specific variables
3. Systemic variables
4. Exogenous variables

Question 17

What are some examples of spontaneous causes that can cause impaired wound healing

Answer 17

• foreign bodies
• infections
• Neoplasia

Question 18

What are some examples of wound specific variables that can cause impaired wound healing?

Answer 18

• Body site
• Vascular supply
• Mechanical stress
• Desiccation

Question 19

What are some examples of systemic variables that cause impaired wound healing

Answer 19

• Nutrition
• Age
• Sex
• Immobility
• Diseases

Question 20

What are some examples of exogenous variables that cause impaired wound healing?

Answer 20

• Medication
• Radiation
• The environment

Question 21

What is the function of fibroblasts?

Answer 21

They help synthesise the Extracellular matrix by producing collagen and proteoglycans
This provides an envoronment for other cells to work

Question 22

What occurs during fibrosis?

Answer 22

Fibroblasts align themselves along the planes of tissue stress during development e.g langers lines

Question 23

What is the benefit of making surgical incisions along the langers lines?

Answer 23

Reduces the post-surgical scar formation
as the skin is less tight

more tension= more fibrosis= harder to pull the sides together

Question 24

What kind of fibroblasts are particularly responsive to injury?

Answer 24

Feline

Question 25

What kind of cells migrate into wounds?

Answer 25

Fibroblasts and endothelial cells

Question 26

What is the function of the growth factors released during inflammation

Answer 26

They promote proliferation of fibroblasts and endothelial cells

Question 27

What is granulation tissue?

Answer 27

A distinctive arrangement of connective tissue fibres, fibroblasts and blood vessels (highly vascularised connective tissue)
they run parallel to the wound surface

Question 28

What is the gross appearance of the granulation tissue

Answer 28

• Red and granular appearance
• New vessels are leaky and they bleed easily

Question 29

What is proud flesh and in what species is it most common?

Answer 29

Proud flesh is uncontrollable growth of granulation tissue when a wound starts healing

Most common in horses

Question 30

What are myofibroblasts and what are their function?

Answer 30

Myofibroblasts are specialised fibroblasts with contractile activity

they form in wounds in response to tissue stress

They can then contract to bring the edges of the wound together

Question 31

What is corneal ulcer healing/ epithelialisation?

Answer 31

Skin and mucus membranes replace superficial epithelial cells

neighbouring epithelial cells separate and migrate to fill the gap and then start to proliferate

Question 32

In what animal do you get the most fibrostic transformation?

Answer 32

Cats

Question 33

What do endothelial cell bud formation and migration into tissues under the influence of?

angiogenesis

Answer 33

IGF- alpha and EGF

Question 34

What is endothelial cell proliferation under the influence of

Answer 34

VEGF

Question 35

What is secondary cell proliferation under the influence of?

Answer 35

angiopoietin 1

Question 36

How does angiopoietin 1 work?

Answer 36

stabilises the vessel by recruiting proteocytes and smooth muscle cells and then ECM protein deposition

Question 37

What is the definition of reepithelialisation?

Answer 37

The process by which skin and mucous membranes replace superficial epithelial cells that are damaged or lost in a wound