Injury To The Body

Question 1

Excessive mechanical force can cause:

Answer 1

Compression

Traction (stretching)

Torsion (twisting)

Tangential (shearing)

Question 2

Classification of injury

Answer 2

By appearance

Manner of causation

Nature of injury

Question 3

What is a contusion?

Answer 3

A bruise - burst blood vessel in skin

Question 4

Blunt force injuries

Answer 4

Contusions

Abrasions(graze/scratch)

Lacerations (cut/tear of skin)

Question 5

What are tramlines bruise?

Answer 5

A cyclindrical instrument
Looks like train-tracks

Finger-tip bruising

Buckle bruise

Tyre bruise

Question 6

What happens in people with liver disease?

Answer 6

Bruises are worse -fall over more and bruises show up worse.

Question 7

What is an abrasion?

Answer 7

Scraping of very top layer

Bread-knife mark

Bite marks

Question 8

Lacerations

Answer 8

Not usual patterned
Blunt force injury

‘Stringy bridges’

Question 9

Sharp force injuries

Answer 9

Injury caused by sharp cutting edged implement

Incised wounds - more superficial, longer on surface than deep (slash)

Stab wounds - deeper penetrating, deeper than wider on surface

Question 10

What is a vital reaction?

Answer 10

Inflammatory- bleeding bruising etc

Question 11

Early post-mortem changes?

Answer 11

Temp degradation

Hypostasis

Rigor mortis

Question 12

Last post-morgen changes

Answer 12

Decomposition and autolysis

Mummification

Adipocere

Skeletonisation

Question 13

Hypostasis

Answer 13

When circulation ceases

RBCs seen through skin, gives colour - pink/purple

Oedema and skin blisters

Dully established by 6-12 hours

Question 14

What is rigor mortis?

Answer 14

Stiffening and shortening of muscle fibres leading to rigidity of musculature and fixation of joints.

Due to reduction of ATP within muscles
‘Stuck’ in contraction

Question 15

Factors affecting timing of rigor mortis:

Answer 15

Temperature
Physical activity before death - more - rigor quicker 
Body temp at time of death
Convulsions
Electrocution

Question 16

Decomposition 2 classes?

Answer 16

Putrefaction = microbiological degeneration

Autolysis = endogenous proteolytic degeneration

Question 17

Putrefaction

Answer 17

Fern-like pattern of venous staining

After time, less well-defined.

Skin slippage

Gas produced by bacteria - very swollen

Question 18

Mummification

Answer 18

Body ‘dries out’

Children prone to mummification

Question 19

Adipocere

Answer 19

Waxy material on skins surface which hardens when dries out

Tends to occur in wet/ damp environments

Question 20

Skeletonisation

Answer 20

All soft tissue completely degrades, left just with bones.

Question 21

Estimating time since death

Answer 21

0-12 hours = body temp most useful - 1C drop per hour
24 hrs = rigor mortis and hypostasis
48hrs-3weeks = putrefaction
Months to years = adipocere, mummification, skeletonisation