ASM 275 Unit 3 - Study Guide Exam
With Complete Solutions
Perimortem - ANSWER injury happened near time of death (helps to reconstruct cause
and manner of death)
Antemortem - ANSWER injury happened before death (used to link medical records)
Postmortem - ANSWER there is no injury, the bone breakage occurred after death
(doesn't contribute to forensic analysis)
How to differentiate perimortem, antemortem, and postmortem trauma? - ANSWER
Antemortem Trauma
1) hematoma forms: blood pools over surface - internal scab to help stabilize the break
2) callus formation: woven bone deposited
3) remodeling of woven bone into mature bone
- process of bone healing should be present (increase porosity/holes of bone near
break, rounding of broken edges <1 week, callus presence 6+ weeks)
- remodeling (years, can sometimes never fully heal/callus never goes away)
Perimortem Trauma
- no signs of heeling
- green bone response
1) sharp edges of fracture and lines
2) hinging - not seen in postmortem fractures
3) fracture lines
4) angled broken ends
5) hematoma staining
Postmortem Trauma
- not related to death, occurs after death
1) do not have fracture lines
2) greenstick and hinge fractures absent
, 3) breaks occur at right angles to bone shaft
Blunt Force Trauma: types of objects - ANSWER - blunt instruments (crowbars,
baseball bats)
- car/train/airplane crashes
- abrasions of all kinds ('Road Rash')
- bites
- falls
Blunt Force Trauma:
- laceration
- contusion
- abrasion - ANSWER Laceration: a tear in the skin caused by a blunt instrument
- can be distinguished from a sharp force injury because they often have contusions
(strings of flesh)
Contusion: a brusie
- almost always blunt force'
- a bruise changes in color from light bluish red to dark purple, then to green, then to
yellow, then to brown. this can help you tell the difference between antemortem and
perimortem trauma
- a bruise may not be immediately apparent on initial examination, but may become
readily observable some hours or days later
Abrasion: superficial scraping and/or stretching
- scraping and removal of superficial layers of skin
- road rash: body dragged along paved area
- stretching abrasion: caused by stretching of skin beyond its elastic tolerance, as is
also often seen in road accidents
Blunt Force Trauma: radiating and concentric fractures - ANSWER radiating fracture
lines associated with blunt force trauma form on the inner surface of cranial bones and
travel outward towards the visible surface of the skull
- originate from the primary impact site and often create a series of triangular wedge-
shaped pieces of bone that point toward the are of impact
concentric fractures form surrounding the primary impact site if the radiating fractures
do not alleviate the stress of energy absorption
Blunt Force Trauma: Buttressing and LeFort fractures - ANSWER Buttressing
1) mid-occipital (back of skull)
2) posterior temporal (behind ear)
3) anterior temporal (behind eye)
4) mid-frontal (middle of forehead)
- force from a blow to the vault will cause fractures between these buttresses
With Complete Solutions
Perimortem - ANSWER injury happened near time of death (helps to reconstruct cause
and manner of death)
Antemortem - ANSWER injury happened before death (used to link medical records)
Postmortem - ANSWER there is no injury, the bone breakage occurred after death
(doesn't contribute to forensic analysis)
How to differentiate perimortem, antemortem, and postmortem trauma? - ANSWER
Antemortem Trauma
1) hematoma forms: blood pools over surface - internal scab to help stabilize the break
2) callus formation: woven bone deposited
3) remodeling of woven bone into mature bone
- process of bone healing should be present (increase porosity/holes of bone near
break, rounding of broken edges <1 week, callus presence 6+ weeks)
- remodeling (years, can sometimes never fully heal/callus never goes away)
Perimortem Trauma
- no signs of heeling
- green bone response
1) sharp edges of fracture and lines
2) hinging - not seen in postmortem fractures
3) fracture lines
4) angled broken ends
5) hematoma staining
Postmortem Trauma
- not related to death, occurs after death
1) do not have fracture lines
2) greenstick and hinge fractures absent
, 3) breaks occur at right angles to bone shaft
Blunt Force Trauma: types of objects - ANSWER - blunt instruments (crowbars,
baseball bats)
- car/train/airplane crashes
- abrasions of all kinds ('Road Rash')
- bites
- falls
Blunt Force Trauma:
- laceration
- contusion
- abrasion - ANSWER Laceration: a tear in the skin caused by a blunt instrument
- can be distinguished from a sharp force injury because they often have contusions
(strings of flesh)
Contusion: a brusie
- almost always blunt force'
- a bruise changes in color from light bluish red to dark purple, then to green, then to
yellow, then to brown. this can help you tell the difference between antemortem and
perimortem trauma
- a bruise may not be immediately apparent on initial examination, but may become
readily observable some hours or days later
Abrasion: superficial scraping and/or stretching
- scraping and removal of superficial layers of skin
- road rash: body dragged along paved area
- stretching abrasion: caused by stretching of skin beyond its elastic tolerance, as is
also often seen in road accidents
Blunt Force Trauma: radiating and concentric fractures - ANSWER radiating fracture
lines associated with blunt force trauma form on the inner surface of cranial bones and
travel outward towards the visible surface of the skull
- originate from the primary impact site and often create a series of triangular wedge-
shaped pieces of bone that point toward the are of impact
concentric fractures form surrounding the primary impact site if the radiating fractures
do not alleviate the stress of energy absorption
Blunt Force Trauma: Buttressing and LeFort fractures - ANSWER Buttressing
1) mid-occipital (back of skull)
2) posterior temporal (behind ear)
3) anterior temporal (behind eye)
4) mid-frontal (middle of forehead)
- force from a blow to the vault will cause fractures between these buttresses
