Healing

Question 1

Does healing happen before or after inflammation?

Answer 1

After, but can be quick/almost immediately

Question 2

What factors influence wound healing time?

Answer 2

Blood flow
Size and location of wound
Disease
Medications
Possible infections
General health (smoking drinking etc.)

Question 3

What are the two main steps to the healing process?

Answer 3

Regeneration
Repair

Question 4

What is regeneration?

Answer 4

Replacement of original tissue with functional tissue of the same type

Question 5

What type of cells are capable of regeneration?

Answer 5

Cells that are capable of mitosis

Question 6

What are some examples of cells incapable of regeneration?

Answer 6

Cardiac cells
Skeletal muscle cells
Neurons

All incapable of mitosis

Question 7

What is stroma?

Answer 7

Connective tissues which help cells stay in place. Supports vessels, ducts, tissue etc.

Question 8

What is repair?

Answer 8

Replacing original tissue with scar tissue

Question 9

Is regeneration or repair more common?

Answer 9

Repair

Question 10

What is scar tissue and what is it composed of?

Answer 10

Non-functional connective tissue primarily made up of type I and type II collagen or astrocytes in neural tissue

Question 11

What are the 3 main factors released by macrophages during bone fracture healing and their main effects?

Answer 11

1) Fibroblast activator - secretes the ingredients for collagen
2) Angiogenesis factor - promotes revascularsation
3)Osteogenesis factor - increase in osteoblasts

Question 12

What happens during clotting after a bone fracture?

Answer 12

Bleeding vessels activate fibrin to form a clot.
The clot contains a think entanglement of fibres with white blood cells.
Immediately macrophages flood the area attracted by inflammatory chemicals and start breaking down the clot using a plasmin enzyme which breaks down fibrin.
The macrophages create tunnels and release 3 activating substances

Question 13

What is the purpose of the fibroblast activator released by macrophages?

Answer 13

The fibroblast activator secretes the ingredients for collagen, these ingredients mix together to form granulation tissue which eventually replaces the clot.
Specialised fibroblasts contract the wound pulling the edges in in an attempt to decrease area and promote faster healing.

Question 14

What promotes necrotic bone reabsorption?

Answer 14

Broken vessels cause a build up of Co2
The area becomes slightly acidic which favours osteoclast reabsorption

Question 15

What does angiogenesis factor cause in bone fracture healing?

Answer 15

The sprouting of new blood vessels

Question 16

What does osteogenesis factor cause in bone fracture healing?

Answer 16

An increase in osteoblasts.
A soft, then hard, callus forms - this will be different depending on the tissue type.

Question 17

What is the final step to bone fracture healing?

Answer 17

Bone remodelling

Question 18

What are the main complications of healing?

Answer 18

Scarring - scars are constantly moving and changing e.g.

Contractures
Strictures
Hypertrophic scars
Keloid scars

Question 19

What are contractures?

Answer 19

A remodelling of scars after healing - can cause functional and aesthetic problems

Question 20

What are strictures?

Answer 20

A remodelling of scars in tubular organs/passages - can cause serious functional problems

Question 21

Where are fibroblasts found?

Answer 21

Connective tissue, stroma and skin all around the body

Question 22

What factors may delay healing?

Answer 22

Advanced age (reduced mitosis)
Poor nutrition
Dehydration
Anaemia
Poor circulation
Some chronic diseases (e.g. diabetes)
Irritation
Bleeding
Mobility of wound
Infection
Foreign body
Radiation
Steroid use