NExT Forensic Medicine, Toxicology and Medical Ethics Syllabus

How do you differentiate antemortem burns from postmortem burns?

Antemortem: red vital reaction/line of redness at margins, blisters contain fluid rich in protein/albumin and chlorides with red base, carbon (soot) in air passages, raised carboxyhaemoglobin in blood. Postmortem: no vital reaction, blisters contain air, no soot in airways.

What are the post-mortem features of death due to lightning and electrocution?

Lightning: arborescent/filigree (Lichtenberg) skin markings, singeing of hair, magnetization of metal objects, ruptured clothing. Electrocution: Joule burn (electric mark) with raised firm collar at entry, blister with central crater, metallization of skin, cardiac arrhythmia as cause of death.

Classify mechanical injuries (wounds) into the main types.

Blunt force injuries: abrasions, contusions (bruises), lacerations. Sharp force injuries: incised wounds, stab/punctured wounds, chop wounds. Plus firearm injuries and regional injuries. Fractures and dislocations are bony mechanical injuries.

Differentiate an incised wound from a lacerated wound.

Incised wound: clean-cut by sharp edge, length exceeds depth, edges clean and everted, no tissue bridging, margins regular. Laceration: split/tear by blunt force, margins irregular and contused/abraded, tissue bridges across the wound, hair bulbs crushed.

How are abrasions classified and what is their medico-legal importance?

Types: scratch (linear), graze (sliding/brush), pressure/imprint (patterned, e.g., ligature, tyre), impact abrasions. Importance: indicate site of impact, pattern of weapon, direction of force, type of crime (e.g., nail marks in throttling), and are antemortem when there is a vital reaction.

Distinguish an entry wound from an exit wound in a firearm injury.

Entry: smaller, inverted margins, abrasion collar and grease/dirt collar present, contusion ring, may show tattooing/blackening at close range. Exit: usually larger, everted margins, irregular/stellate, no abrasion collar, no tattooing or grease ring.

Describe the firing range determination in firearm wounds (contact, close, near, distant).

Contact: muzzle imprint, blackening, cherry-red CO around wound, stellate wound. Close (within ~30 cm): blackening (smoke soot) plus burning/singeing. Near/intermediate (up to ~1 m): tattooing/stippling from unburnt powder. Distant (beyond ~1 m): only the bullet hole with abrasion collar, no soot or tattooing.

What is a coup and contrecoup injury in head trauma?

Coup injury: brain contusion directly beneath the site of impact (typical of a moving object striking a stationary head). Contrecoup injury: contusion on the side opposite to impact (typical of a moving head striking a fixed object), commonly affecting frontal and temporal poles.

Differentiate extradural, subdural, and subarachnoid haemorrhage by source and characteristics.

Extradural: arterial (middle meningeal artery), associated with temporal skull fracture, lucid interval, biconvex/lens-shaped clot. Subdural: venous (bridging veins), crescentic clot, common in elderly/alcoholics. Subarachnoid: ruptured berry aneurysm or trauma, blood in CSF spaces.

List the primary methods of personal identification of the living and the dead.

Race, religion, sex, age, stature, complexion, hair, eyes, teeth (odontology), fingerprints (dactylography), scars, tattoos, deformities, anthropometry, DNA fingerprinting, superimposition, and gait. Fingerprints and DNA are the most reliable.

How is sex determined from the skull and the pelvis?

Pelvis is the most reliable bone for sex. Female pelvis: wider/shallower, broad greater sciatic notch, subpubic angle >90°, oval inlet, presence of preauricular sulcus. Male skull: larger, more prominent supraorbital ridges, square chin, larger mastoid process and rougher muscle markings.

What is the importance of ossification centres in age estimation?

Appearance and fusion (union) of ossification centres in epiphyses indicate age. Examples: union of lower end of radius ~17-20 yrs, head of humerus ~18-20 yrs, iliac crest ~21-23 yrs. They allow age estimation up to ~25 years before all epiphyses fuse.

Describe the medico-legal aspects of fingerprints (dactylography) and Galton's patterns.

Fingerprints are unique and permanent. Galton classified ridge patterns into loops (most common ~67%), whorls (~25%), arches (~6%), and composites. Used for criminal identification; the Henry system classifies them for filing. No two individuals (even twins) share identical prints.

Define rape under the Indian legal framework (Section 63 BNS / earlier 375 IPC) in brief.

Rape is sexual intercourse (penetration, however slight, of penis/object/body part into vagina, mouth, urethra or anus) by a man with a woman against her will, without consent, with consent obtained by fear/fraud, or with consent when she is under 18 years (statutory rape). Marital exception applies above the legal threshold age.

What is the medico-legal evidence to be collected and examined in an alleged rape victim?

Examine clothing, general injuries, marks of struggle, genital examination (hymen, tears, bruises), collect vaginal/cervical swabs for spermatozoa and acid phosphatase, pubic hair combings, nail clippings, blood for DNA/grouping, and document with consent. Spermatozoa and seminal stains are confirmatory.

State the medico-legal importance of the hymen and types of hymenal tears.

An intact hymen suggests but does not prove virginity; an absent/torn hymen does not prove intercourse. Fresh tears (from recent penetration) are red, bleeding, painful; old healed tears show as carunculae myrtiformes after childbirth. Tears are usually posterior in forced penetration.

What are the signs of recent delivery and of remote (past) delivery in a woman?

Recent: enlarged soft uterus, lochia, lax abdominal wall, striae gravidarum (pink/red), engorged breasts with colostrum, torn vaginal/perineal tissues. Remote: white silvery striae, patulous os with transverse cervical tear, pendulous abdomen, pigmented areolae.

Define legitimacy and the medico-legal concept of the longest and shortest period of gestation in disputed paternity.

A child born during a valid marriage or within a defined period after its dissolution is presumed legitimate. Average gestation ~280 days. Legally accepted minimum viable gestation is ~210 days (28-32 weeks) and the maximum period claimed in disputed legitimacy may extend to ~349 days; courts decide on evidence.

Distinguish between cognizable and non-cognizable offenses, and bailable vs non-bailable.

Cognizable: police may arrest without warrant and investigate without magistrate's order (e.g., murder, rape). Non-cognizable: warrant/magistrate order needed. Bailable: bail is a right. Non-bailable: bail is at the court's discretion. Serious offenses are usually cognizable and non-bailable.

Differentiate inquest types: police inquest and magistrate's inquest.

Police inquest (Section 174 CrPC / BNSS): conducted by police officer to ascertain apparent cause of death. Magistrate's inquest: by executive/judicial magistrate, mandatory in cases of death in police custody, dowry death, death in prison, and exhumation. Coroner's inquest is now obsolete in India.

What is dying declaration and dying deposition, and their evidentiary value?

Dying declaration: a statement by a dying person about the cause/circumstances of their impending death, admissible even without oath or cross-examination (under the principle that a dying person rarely lies). Dying deposition: recorded by a magistrate on oath in the presence of the accused, with cross-examination; it has higher evidentiary value.

What are the essential components of a properly written medico-legal report and a death certificate?

MLR includes: identification details, consent, history/alleged manner, examination findings, opinion, and signature. A death certificate must record the immediate cause, antecedent causes, and underlying cause of death (per WHO/ICD format on Form 4/4A), avoiding mode-of-death terms like cardiac/respiratory arrest as the cause.

Define poison and classify poisons based on their mode of action.

A poison is any substance that, when introduced into or applied to the body, can cause ill health or death by its chemical action. Classified as: corrosives (acids, alkalis), irritants (metallic, vegetable, animal, mechanical), neurotics (CNS - cerebral, spinal, peripheral), cardiac, asphyxiants, and miscellaneous.

State the general principles of treatment of an acute poisoning case.

Stabilize ABC (airway, breathing, circulation); remove unabsorbed poison (gastric lavage, activated charcoal, induced emesis where appropriate); administer specific antidote; enhance elimination (forced diuresis, dialysis, alkalinization); and give supportive/symptomatic care. Avoid lavage in corrosive and convulsant poisoning.

List common specific antidotes for: organophosphates, opioids, paracetamol, methanol, and heavy metals.

Organophosphates: atropine + pralidoxime (oximes). Opioids: naloxone. Paracetamol: N-acetylcysteine. Methanol/ethylene glycol: ethanol or fomepizole. Heavy metals: BAL (dimercaprol), EDTA, D-penicillamine, DMSA. Cyanide: amyl/sodium nitrite + sodium thiosulphate.

Describe the features and treatment of organophosphate (agrochemical) poisoning.

Inhibits acetylcholinesterase causing cholinergic excess: muscarinic (SLUDGE - salivation, lacrimation, urination, defecation, GI cramps, emesis, miosis, bradycardia), nicotinic (fasciculations, weakness), and CNS effects. Garlic odour. Treatment: atropine to dryness plus pralidoxime, and decontamination.

What are the features of corrosive acid versus corrosive alkali poisoning?

Acids (sulphuric, nitric, HCl) cause coagulative necrosis with hard eschar; burns are dry, with coloured stains (sulphuric-black, nitric-yellow/xanthoproteic). Alkalis cause liquefactive necrosis, soft soapy slippery burns, deeper penetration. Both are contraindications to gastric lavage and emetics; risk of perforation and stricture.

Describe acute alcohol (ethanol) intoxication stages and the medico-legal blood alcohol thresholds.

Stages by blood alcohol: subclinical, excitement, incoordination, confusion, stupor, coma, death (around 400-500 mg/dL). The legal driving limit in India is 30 mg/100 mL of blood. Features include disinhibition, slurred speech, ataxia, and the smell of alcohol; fatal dose roughly 150-250 mL absolute alcohol.

What are the features of arsenic and lead poisoning (metallic poisons)?

Arsenic (acute): rice-water stools, garlicky breath, vomiting, shock; chronic: hyperpigmentation, hyperkeratosis, Mees' lines on nails, peripheral neuropathy. Lead (chronic plumbism): burtonian blue line on gums, basophilic stippling, wrist/foot drop, anemia, colic, encephalopathy. Antidotes: BAL/DMSA for arsenic, EDTA/DMSA for lead.

Name a key feature each of these plant/animal poisons: Datura, Abrus precatorius, Oleander, and snake venom.

Datura (dhatura, atropine): anticholinergic - dry mouth, dilated pupils, delirium, 'mad as a hatter'; criminal/stupefying poison. Abrus precatorius (rosary pea): abrin, used as 'sui' needles for cattle poisoning. Oleander: cardiac glycosides causing arrhythmia. Snake venom: neurotoxic (cobra/krait - paralysis) or vasculotoxic (viper - bleeding/local necrosis); treat with polyvalent antivenom.

State the four pillars/principles of medical ethics (bioethics).

Autonomy (respect for the patient's right to self-determination and informed consent), Beneficence (act in the patient's best interest), Non-maleficence (do no harm - primum non nocere), and Justice (fair and equitable distribution of care and resources).

Differentiate the 4 Ds required to establish medical negligence and the doctrine of Res Ipsa Loquitur.

The 4 Ds: Duty of care owed, Dereliction (breach of that duty), Direct causation, and Damage resulting. Res ipsa loquitur ('the thing speaks for itself') applies when negligence is so obvious that the mere occurrence proves it (e.g., instrument left in abdomen), shifting the burden of proof to the doctor.