Test 3 Death, Trauma and the Skeleton

Question 1

Trauma def

Answer 1

• Pathological category defined as an injury caused to living tissues by an outside force

Question 2

Outside forces

Answer 2

• Blunt objects, projectiles, cutting instruments, chopping tools
• Hard surfaces (ground, car/trains, aircraft accident)
• Chemicals
• Fire and frost

Question 3

Trauma and Law (2)

Answer 3

1. Cause and Manner of Death
2. Characteristics of the attacker

Question 4

Cause and Manner of Death (5)

Answer 4

1. Trauma that occurred at time of death (perimortem)
2. Outside force that caused the death
3. Number of wounds
4. Multiple traumas- mostly= rage/domestic death
5. Placement of the traumas

Question 5

Characteristics of the attacker (3)

Answer 5

1. Height- Location and angle of the trauma
2. Sex- Stats= diff way to kill->
   - Men= more violent, messy, face-to-face (Blunt trauma w metal pipe or strangulation)
   - Women= More indirect (ex. Poisonning)
3. Handedness: Location of trauma/wounds

Question 6

Bone Traumas (2)

Answer 6

1. Fracture- When the discontinuity travels completely through the bone
2. Infraction- When the discontinuity is incomplete

Question 7

Types of bone breakage (4)

Answer 7

1. Complete fracture- When once continuous surfaces no longer meet
2. Hinge fracture- Part of the fracture is still attached to its original bone but not the other segment
3. Comminuted fracture- Breaks that result in multiple fragments of bones. Common in violent deaths/homicides (crushing w a club), suicide (high fall, moving vehicle), and accidents (car crash).
4. Fracture lines: - Radiating lines
   - Concentric lines

Question 8

Fracture lines- Radiating lines

Answer 8

Disperse outward from the area of impact
- Most common fracture lines

Question 9

Fracture lines- Concentric lines

Answer 9

Appear around the point of impact
- Common in high-velocity projectiles

Question 10

Breakage caused by non-violent factors (3)

Answer 10

1. Pathological fractures - Osteporosis
2. Stress fractures - Repeated movement (common in athletes)
3. Fatigue fractures - Old age, due to the loss of cartilage

Question 11

Body responses to fracture (4 steps)

Answer 11

ANTIMORTEM bc bone heals
1. Hematoma- Pool of blood around injury that stabilizes it (bruises)
2. Osteogenesis- Production of FLEXIBLE bone fiber
3. Callus- Flexible bone fiber turn into a bump
- 2 weeks = soft
- 4 weeks = hard
4. Bone fibers becomes true bone - After 4 weeks

Question 12

Characteristics of Force causing trauma (3)

Answer 12

1. Direction:
   
   • Tension
   • Compression
   • Torsion
   • Bending
   • Shearing
2. Speed of force
   
   • Dynamic force
   • Static force
3. Focus of force
   
   • Narrow focus
   • Wide focus

Question 13

Direction- Tension

Answer 13

Pulls on bones usu. on its long axis.
If tension is strong enough, will cause the bone to break

Question 14

Direction- Compression

Answer 14

Pushes down on bones.
Produces fractures and fracture lines

Question 15

Direction- Torsion

Answer 15

One part of the bone remains immobile while another segment twists.
Not very common in homicide- ex. ski/bicycle accident

Question 16

Direction- Bending

Answer 16

Impacts the side at about right angles causing a break horizontally- Like breaking a branch.
Most commonly causing fractures
-> Parry Fracture: When someone holds their forearm up to protect themself. Blow is entirely absorbed by the ulna, causing it to bend and break= Defensive wound.

Question 17

Direction- Shearing

Answer 17

Similar to bend, but only one side of the bone bends and the other segment remains immobile
-> Colle’s fracture: When one falls and attempt to protect themselves with their forearms. Side of the body exerts a pressure to the side of the radius.

Question 18

Speed of force- Dynamic force

Answer 18

Sudden stress delivered powerfully and at a high speed.
Most common force seen in violent death

Question 19

Speed of force- Static force

Answer 19

Stress applied slowly then builds up to the point where the bone breaks.
Ex.: the breaking of the hyoid bone in the throat by strangulation (most common static force)

Question 20

Focus of force- Narrow

Answer 20

Force is applied to a single point or a thin line
-> Pointed/sharp-edged instruments. Ex.: ice picks, knives, machetes, swords…

Question 21

Focus of force- Wide

Answer 21

Force is delivered over a large area of the bone.
-> Any other instruments other than cutting/chopping ones

Question 22

Type of Trauma (4)

Answer 22

1. Blunt trauma
2. Sharp trauma
3. Projectile trauma
4. Miscellaneous trauma

Question 23

Blunt trauma

Answer 23

Caused by a force that has a wide area of impact on bones.
Generally caused by: bending, shearing
dynamical and wide focus
Causes: hinge or complete fracture, and often comminuted fractures with fracture lines (both)

Question 24

Sharp trauma

Answer 24

• Compression or shearing
• Axe= comminuted fractures with radiating lines
• Focus= narrow (knives) or wide (axe)
• Speed= dynamic

Question 25

Projectile trauma

Answer 25

- Compression and bending - Speed= dynamic - Focus= narrow at point of entry, but wide upon exiting - Comminuted fractures with fracture lines (both)

Question 26

Miscellaneous trauma

Answer 26

Trauma that do not fit into other categories - Static pressure: strangulation - Generalized dynamic pressure: explosions - Traumas caused by chemicals and heat Varies...

Question 27

Timing of bone injury (3)

Answer 27

1. Antemortem trauma 2. Perimortem trauma 3. Postmortem trauma

Question 28

Antemortem trauma

Answer 28

Clearest evidence= callus bump How to recognize a Callus: - Irregular shape - Disorganized surface - Raised above surrounding area

Question 29

Perimortem trauma

Answer 29

Injuries that occurs around the time of death 3 main distinctive characteristics: 1. Breakage displays sharp and irregular edges 2. Formation of fracture lines (only on moist bones)- radiating or concentric 3. Shape of broken ends- do not fracture at right angle, nor have flat broken surfaces. -> Dry bones do= diff btw peri/post

Question 30

Postmortem

Answer 30

Fracture to dry bones : 3 main distinctive characteristics: 1. No fracture lines 2. Bones break at right angles w almost flat surfaces 3. The color of the bone is diff. Broken surface will be normally lighter in color than other bone surfaces