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FM5.1-6,FM14.{1,9-10} | Mechanical Injuries & Wounds — Graded Quiz
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An autopsy reveals a wound on the anterior chest that is 3 cm long, 0.5 cm wide at the surface, with clean margins and penetrates 9 cm to enter the right ventricle. Which wound description is CORRECT?
Stab wound: depth 9 cm > surface length 3 cm, with clean margins and penetration of deep structures. This is the defining depth > length criterion for stab wounds.
Stab wound dimensions: report surface length × width at widest point, depth, track direction, and structures penetrated. Depth > length = stab. Weapon shape inference from wound shape (single vs double edge).
Laceration has ragged margins and tissue bridges. Incised = length (3 cm) > depth — not met here. Chop = heavy blade, bone involvement, contused margins. This wound meets stab criteria precisely.
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A patient presents with a fracture of the nasal bones and a deep laceration of the scalp causing 22 days of incapacitation. Under BNS, this injury should be certified as:
Two independent grievous hurt criteria are met: (1) fracture of bone (nasal bone = bone fracture), and (2) incapacitation for 22 days > 20-day threshold. Document both separately in the certificate.
Always assess ALL 8 grievous criteria independently. Multiple criteria can be met simultaneously. Report each grievous criterion separately. Incapacitation is 'unable to follow ordinary pursuits' — not just hospitalisation.
Culpable homicide requires death. Nasal bone IS a bone fracture (grievous). Laceration alone is simple hurt; but incapacitation > 20 days makes it grievous independently. Both criteria present → grievous.
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At autopsy, a body has multiple bruises at different stages. One bruise shows green discolouration with histological evidence of haemosiderin deposition. This bruise is MOST likely:
Green discolouration = haemosiderin deposition from degrading haemoglobin; typically appears at 3-5 days. This helps distinguish recent injuries from older ones in suspected repeated abuse.
Multi-stage bruising on the same victim (different colours at autopsy) suggests repeated assaults over days — a key finding in domestic violence and child abuse cases. Document colour + histology for each bruise.
Fresh (0-12 h) = red/dark red; 1-2 days = purple/blue; 3-5 days = green (haemosiderin); 5-7+ days = yellow (bilirubin). Green + haemosiderin = 3-5 days.
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A railway track death shows the following wounds: multiple lacerations with tissue bridges, avulsion of limbs, patterned abrasions matching the metal track texture, and bone fragments extruded from wound edges. The MOST appropriate classification of the primary wound mechanism is:
Railway injury: massive blunt crush force → lacerations (ragged, tissue bridges), avulsions, patterned abrasions from track texture, and crush fractures. The mechanism is blunt, not sharp, force.
Railway deaths: patterned abrasions (track texture imprint), extensive lacerations, avulsion, crush fractures — all blunt mechanism. Distinguish antemortem (vital reaction, bruising) from postmortem dismemberment.
Rails are not cutting implements. Chop wounds require a bladed instrument. Stab wounds require a pointed weapon. Patterned abrasions + tissue bridges + avulsion = hallmarks of blunt force/crush injury.
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A police officer requests a wound certificate for a person arrested for assault. The examining doctor finds a single minor abrasion on the right forearm, 1 × 0.5 cm. The CORRECT opinion in the certificate is:
A minor abrasion affecting only the epidermis, healing completely without scarring = simple hurt. Always certify based on actual wound nature, not presumed seriousness of the case.
Simple hurt = any hurt not meeting the 8 grievous criteria. Classify based on wound characteristics at the time of examination. Never inflate classification due to police/court pressure.
Grievous hurt requires one of the 8 specific criteria. A small abrasion meets none of them. Speculative infection risk does not elevate it to 'dangerous to life.' Medico-legal importance of the case does not change the wound classification.
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A stab wound on the left chest shows a wound with one squared (blunt) end and one sharp angular end at the skin surface. This pattern MOST suggests the weapon was a:
Single-edged knife: sharp edge produces a narrow angular cut at one end; blunt spine produces a squared/notched end at the other. Double-edged dagger = both ends angular/pointed.
Weapon identification from stab wound: single-edged = 1 pointed + 1 squared end; double-edged = 2 pointed ends; screwdriver/awl = rounded/cross-shaped; scissors = 2 separate triangular wounds.
Double-edged = both ends angular. Screwdriver = circular punch wound. Scissors = complex Y-shaped or double-angular wound. Single-edge = one acute end (cutting edge) + one blunt squared end (spine).
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A 'contrecoup' injury of the brain following a fall is BEST explained by:
Contrecoup: when a moving head suddenly decelerates (fall), the brain continues moving, strikes the skull on the opposite side from initial impact → contrecoup contusion. Worse than coup in deceleration injuries.
Coup vs contrecoup: coup = at impact (direct blow); contrecoup = opposite side (fall/deceleration). In assaults (moving object hits stationary head) → predominantly coup. In falls (moving head hits stationary object) → predominantly contrecoup.
Coup = injury at impact site; contrecoup = opposite side; DAI = shearing from rotation (no single impact site); epidural = often at fracture site. Contrecoup specifically = brain rebound injury on opposite side.
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A post-mortem examination is performed on a victim with a single gunshot wound. The wound of entry shows a round hole with inverted margins, abraded collar, and blackening limited to the skin surface. The wound of exit is irregular with everted margins and no abrasion collar. The estimated firing range is MOST consistent with:
Blackening on skin without tattooing (unburnt powder grains) or burning of hair = intermediate range (15-100 cm): soot deposits but powder particles have dispersed. No gas entry, no burning.
Firearm range estimation: contact → gas tearing + muzzle mark; close (< 15 cm) → burning + tattooing; intermediate (15-100 cm) → blackening only; long range → abrasion collar + inverted margins only.
Contact: muzzle mark, gas tears, grease imprint, stellate laceration, gas in wound. Close (< 15 cm): burning of hair + tattooing. Intermediate (15-100 cm): blackening but no tattooing. Long range (> 100 cm): abrasion collar only, no blackening.
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A victim presents with 'grievous hurt' — permanent disfiguration of the face. Under BNS, the word 'permanent' in this context means:
Permanent disfiguration = cannot be remedied by ordinary surgical means accessible to the patient at the time of examination. If corrective surgery is available and accessible, the disfiguration is not 'permanent' under law.
Permanency in BNS: tested against 'ordinary accessible surgical means' available to the patient. Document whether corrective surgery is feasible and accessible. Legal opinion not medical perfection.
Time-based definitions (3 months, 6 months) are not the legal standard. The test is whether ordinary accessible surgery can reverse it — not advanced/specialised surgery, but ordinary means available to the patient.
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Primary wound healing (healing by first intention) occurs when:
Primary healing (first intention): clean wound with approximated edges (surgical or clean incised wound), minimal gap, no infection → heals rapidly with minimal scar by direct re-epithelialisation.
Wound healing types: primary (first intention) = clean + approximated + no infection; secondary (second intention) = open + granulation; tertiary (third intention) = delayed closure. Relevant for wound age and medico-legal documentation.
Granulation tissue filling and scar contraction = secondary healing (second intention), used when wound edges cannot be approximated or infection is present. Third intention = delayed primary closure.
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