PoD - Injuries to the Body

Question 1

what is an injury?

Answer 1

• physical harm or damage
• used in conjunction with wound
• damage can be caused by physical, heat, cold, electricity, chemicals, radiation

Question 2

what is a lesion?

Answer 2

• any area of injury, disease or local degeneration in a tissue causing a change in it’s structure or function

Question 3

what is a defect?

Answer 3

• term to be used when unsure of the mechanism of injury

Question 4

what can influence an injury?

Answer 4

• degree of force applied
• area of application of force
• duration of application
• direction of application
• tissue properties

Question 5

what is wounding potential?

Answer 5

• the likelihood of the insult to cause injury
• wounding potential comes from velocity
  E = 0.5(mass of object) x (velocity)^2

Question 6

list the types of mechanical forces causing injury

Answer 6

• impact (direct)
• angulation
• compression
• traction
• torsion
• shearing (opposite actions)
• acceleration/deceleration

Question 7

what are blunt force injuries?

Answer 7

• abrasion
• intradermal bruise
• bruise
• laceration

Question 8

what are abrasions?

Answer 8

• injury to skin surface
• superficial/partial injury to epidermis (top layer of skin)
• can be from crushing, scraping
• tags can demonstrate directional force
• bleeding is slight
• heal quickly by forming a scab
• leave no scar

Question 9

what are bruises?

Answer 9

• bruising is caused by burst blood vessels in skin
• occurs in the dermis
• patterned bruising - ‘tram-track’ bruising = rod, baton or plank-like object or discoid bruises = finger tips
• interpreting bruising can be difficult, but have to look at: depth bruise develops, site of bruise/impact, appearance, shape rarely reflects shape or object, size rarely reflects severity

Question 10

what are lacerations?

Answer 10

• cut/tear/splitting of skin due to crushing
• can be superficial or partial
• tends to be more common in areas where skin is fixed to bone
• caused by impact against flat surface, impact by an edged or pointed object, rotation of tissue on limb/torso, excess frictional or tearing forces

Question 11

what are sharp force injuries?

Answer 11

• injury caused by any weapon with sharp cutting edge (knife, glass, razorblade)
• can be superficial or penetrating
• incised or stab wounds

Question 12

what are incised wounds?

Answer 12

• superficial sharp force injury caused by slashing motion
• majority are knife wounds or glass, razor, metal sheet, plastic
• injury is longer on the skin surface than it is deep
• clean cut of blood vessels = means it will bleed profusely
• well defined margins
• no associated bruising or abrasion of wound edges
• no tissue bridges formed
• swiping, slashing or slicing action along the surface of the skin
• can be by accident, suicide, homicide
• need to note site of accessibility, sites of harm, sites of pain, sites that can be concealed

Question 13

what are stab wounds?

Answer 13

• a penetrating injury resulting from thrusting motion
• wound depth is greater than length on surface
• involves full thickness of skin and extends into underlying tissues
• not associated with abrasion or bruising
• clean division of all tissues within the wound tract
• can be accident, suicide or homicide

Question 14

what is a chop wound?

Answer 14

• a mix between a sharp and blunt force injury
• tends to occur with heavy-bladed instruments (axe, machete, meat cleaver…)
• abrasion +/- bruising of wound margins
• longer than it is deep