NEET PG Forensic Medicine Syllabus

What are the main objectives of a medico-legal (forensic) autopsy?

To establish the identity of the deceased, determine the cause, manner, and time of death, recover/document evidence (injuries, projectiles, samples), and assist the legal investigation. It is ordered by a magistrate/police; consent of relatives is not required.

What is the difference between cause, manner, and mechanism of death?

Cause = the disease/injury responsible (e.g., gunshot wound). Mechanism = the physiological derangement producing death (e.g., hemorrhage). Manner = how the death came about: natural, accidental, suicidal, homicidal, or undetermined.

In mass disasters, what are the primary versus secondary methods of identification of human remains?

Primary methods: DNA profiling, fingerprints, and dental (odontological) comparison. Secondary methods: medical findings, personal effects, tattoos, scars, clothing, and visual recognition (less reliable alone).

How are injuries (wounds) broadly classified by the causative agent?

Mechanical (blunt-force: abrasion, contusion, laceration; sharp-force: incised, stab/chop; firearm), thermal (burns, scalds, frostbite), chemical (corrosives), electrical, and explosive/blast injuries.

What is the difference between an abrasion, a contusion, and a laceration?

Abrasion: superficial injury of the epidermis (graze/scratch). Contusion (bruise): rupture of subcutaneous vessels causing extravasation with intact skin. Laceration: a tear/split of skin and tissues from blunt force, with irregular ragged margins and tissue bridging.

How does an incised wound differ from a laceration?

An incised wound (from a sharp edge) has clean-cut regular margins, is longer than deep, no tissue bridging, and bleeds freely. A laceration (blunt force) has irregular ragged margins, crushed edges, and tissue bridges (nerves/vessels) across it.

What is a patterned injury and give an example.

A patterned injury is a wound that reproduces the shape of the object causing it. Examples: tramline/railway-track contusion from a rod, tyre-tread marks, or imprint of a belt buckle or weapon.

What is a 'tramline' (railway track) contusion and what causes it?

Two parallel linear bruises separated by a central area of undamaged skin, caused by a cylindrical object/rod. Blood is forced to the margins where the skin stretches and vessels rupture, sparing the directly compressed center.

How can you estimate the age of a bruise (contusion) by its color changes?

Fresh = red/blue; 1-3 days = bluish/purple; 4-5 days = greenish (biliverdin); 7-10 days = yellow (bilirubin/hematoidin); then resolves. Color change progresses red → blue → green → yellow → normal.

In wound ballistics, what are the typical features of a close-range (contact) entry gunshot wound?

Contact wounds show muzzle imprint, blackening/charring, singeing of hair, splitting/stellate laceration (over bone), and a cherry-red color from carbon monoxide in muscle. Soot and gases are driven into the wound track.

How do you distinguish a firearm entry wound from an exit wound?

Entry: usually smaller, round/oval, inverted margins, with abrasion collar and (if close) grime/tattooing. Exit: usually larger, irregular/everted margins, no abrasion collar, no tattooing or grime.

What is the abrasion collar (contusion ring) around a gunshot entry wound?

A circular reddish-brown ring of abraded/contused skin around the entry hole, produced by the spinning bullet inverting and rubbing the skin margins as it penetrates. It confirms the wound as an entry wound.

What is the difference between tattooing, blackening, and scorching in firearm wounds?

Tattooing (stippling) = embedded unburnt/partially burnt powder grains, indicates intermediate range. Blackening (smudging/soot) = deposition of carbon, indicates close range (within ~30 cm). Scorching/singeing = burning of skin/hair, indicates very close/contact range.

What categories of injury severity (hurt) are recognized under Indian law (IPC)?

Simple hurt (IPC 319/323) and Grievous hurt (IPC 320/325). Grievous hurt includes the 8 categories: emasculation, permanent loss of sight/hearing, loss of a limb/joint, fracture/dislocation of bone or tooth, permanent disfigurement of head/face, and any hurt endangering life or causing 20 days of incapacity.

What three questions must a forensic doctor address when interpreting injury patterns on a body?

The nature/type of injury and weapon used, whether the injury is ante-mortem or post-mortem, and the age (time since infliction) of the injury—plus whether it could be self-inflicted, accidental, or homicidal.

How are ante-mortem injuries distinguished from post-mortem injuries?

Ante-mortem wounds show signs of vital reaction: hemorrhage with clotting, swelling/inflammation, retraction of edges, and healing/repair. Post-mortem wounds show little/no bleeding, no clotting, no inflammatory reaction, and yellowish gaping margins.

What are the medico-legally important sexual offenses to know in forensic practice?

Rape (sexual assault), unnatural offenses (sodomy, bestiality), incest, indecent assault, and offenses against children (covered under the POCSO Act in India). Key is distinguishing consensual vs non-consensual and documenting evidence.

In the clinical examination of a sexual assault victim, what general examination findings should be documented?

General demeanor and mental state, clothing (tears, stains), signs of struggle (bruises, scratches, bite marks), and matted hair. Document all marks of violence with site, size, and age before genital examination.

What genital findings are examined in a female sexual assault victim?

Vulva, labia, fourchette, hymen (tears—fresh or old, position by clock-face), vaginal injuries, and presence of stains/secretions. Note that an intact hymen does not exclude penetration and a torn hymen alone does not prove rape.

What forensic samples are collected during examination of a sexual assault victim?

Vaginal/oral/anal swabs and smears (for spermatozoa, semen), pubic hair combings and matted hair, nail clippings/scrapings, stained clothing, blood for DNA/grouping/alcohol, and any foreign material—all properly labeled and chain-of-custody maintained.

What is the medico-legal significance of acid phosphatase and the 'Florence' / 'Barberio' tests in sexual assault?

They help identify seminal fluid. Acid phosphatase (raised in semen) and Florence test (choline crystals) and Barberio test (spermine crystals) are presumptive/confirmatory chemical tests for semen on swabs or clothing.

Define 'viability' and 'live birth' in the medico-legal context of childbirth.

Viability is the capacity of a fetus to lead a separate existence after birth (in India, ~210 days / 7 lunar months). Live birth means the child showed signs of life (breathing, heartbeat, movement) after complete expulsion from the mother.

What is the hydrostatic (Raygat's) test and what does it determine?

The hydrostatic test checks whether a dead newborn breathed (was born alive). Lungs that have respired float in water (due to air); unrespired lungs sink. It helps establish live birth in infanticide investigations, though it has limitations (putrefaction, artificial respiration).

How are poisons classified according to their predominant action?

Corrosives (strong acids/alkalis), Irritants (arsenic, mercury, plant/animal irritants), Neurotics/CNS poisons (somniferous-opium, inebriants-alcohol, deliriants-dhatura, spinal-strychnine), Cardiac poisons (oleander, aconite), and Asphyxiants (CO, CO2, H2S).

What are the major routes of exposure for poisons, ranked by speed of action?

Inhalation (fastest, e.g., gases) > intravenous/parenteral injection > inhalation > mucous membranes/rectal/vaginal > ingestion (oral) > skin (slowest). The faster a poison reaches the blood, the more rapid its effect.

Define toxicokinetics and its four phases.

Toxicokinetics is the study of how a toxin moves through the body over time: Absorption (entry into blood), Distribution (transport to tissues), Metabolism/biotransformation (chemical alteration, mainly hepatic), and Excretion (elimination, mainly renal). Abbreviated ADME.

What is the difference between fatal dose and fatal period of a poison?

Fatal dose is the smallest amount of poison likely to cause death. Fatal period is the time between ingestion of the poison and death. Both vary with the poison, route, individual tolerance, and condition.

What are the key components of injury documentation in a medico-legal report?

For each injury record: type/nature, exact anatomical site, size (length × breadth × depth), shape, margins, direction, color/age, and whether simple or grievous. Use body diagrams/photographs and note ante-mortem vs post-mortem and probable weapon.

What is 'chain of custody' in the collection of forensic evidence?

Chain of custody is the documented, unbroken record of every person who handled an evidence sample from collection to court—including labeling, sealing, and transfer—to ensure the sample is authentic and untampered, preserving its admissibility.

What does 'competency to stand trial' mean in forensic psychiatry?

It is the accused's mental ability at the time of trial to understand the proceedings, comprehend the charges, and rationally communicate with and assist their defense counsel. It concerns present mental state, not the state of mind at the time of the offense.

What is the legal basis of criminal responsibility and the 'insanity defense' (McNaughten Rule)?

Under the McNaughten Rule (basis of IPC Section 84), a person is not criminally responsible if, due to unsoundness of mind at the time of the act, they did not know the nature of the act or that it was wrong or contrary to law. It addresses legal (not just medical) insanity at the time of the offense.