Regeneration And Repair

Question 1

Describe labile cell populations

Answer 1

Normal state is active cell division
Rapid proliferation
Don’t enter Go

Question 2

Give an example of a labile cell population

Answer 2

Epithelia

Question 3

Describe stable cell populations and give an example

Answer 3

Resting state is Go but can be brought out of it to continue dividing
Eg. Hepatocytes, fibroblasts

Question 4

Describe permanent cell populations

Answer 4

Non-dividing

Unable to re-enter the cell cycle

Question 5

Give 2 examples of permanent cell populations

Answer 5

Neurones

Cardiac myocytes

Question 6

What are the steps of angiogenesis?

Answer 6

1. Endothelial proteolysis of basement membrane
2. Migration of endothelial cells
3. Endothelial cells proliferate
4. Maturation and tubular remodelling
5. Recruitment of periendothelial cells

Question 7

Which collagen types are classed as fibrillar?

Answer 7

I - III

Question 8

Which collagen types are classed as amorphous?

Answer 8

IV - VI

Question 9

Describe healing by primary intention

Answer 9

Incised wound
Apposed edges
Minimal clot and granulation tissue
Epidermis regenerates 
Dermis undergoes fibrous repair

Question 10

Describe healing by secondary intention

Answer 10

Due to infarct, ulcer, abscess or any large wound
Extensive loss of cells
Unapposed wound edges
Large clot
Epidermis regenerates from base up 
Lots of granulation tissue
Extensive collagen deposition

Question 11

What are the steps of bone fracture healing?

Answer 11

Haematoma formation (influx of cells and growth factors)
Soft tissue callus
Hard callus
Remodelling (in the direction of mechanical stress)

Question 12

Insufficient fibrosis can lead to …

Answer 12

Wound dehiscence
Hernia
Ulceration

Question 13

What is a keloid?

Answer 13

A scar with excessive collagen synthesis

Grows outside of the wound edges

Question 14

Define lassitude

Answer 14

A state of physical or mental weariness, lack of energy

Question 15

Describe osteogenesis imperfecta

Answer 15

Inborn error of type 1 collagen synthesis
Skeletal weakness - deformities and susceptibility to fractures
Sclerae of eyes appear blue
Autosomal dominant condition

Question 16

Define contractures

Answer 16

Tissue distortions resulting in permanent shortening of a muscle or joint

Question 17

What occurs in the hands and fingers if ischaemia occurs?

Answer 17

Volkmann’s contracture

Question 18

What are the mechanisms by which corticosteroids cause osteoporosis and increased risk of fractures?

Answer 18

Inhibition of osteoblasts
Enhancement of bone resorption (osteoclasts) 
Inhibition of GI calcium absorption 
Increased urine calcium loss
Inhibition of sex steroids

Question 19

Define regeneration

Answer 19

The replacement of dead or damaged cells with functional, differentiated cells to restore normal structure.