Forensic Medicine Practical Revision

Comprehensive vocabulary flashcards summarizing major forensic concepts, injury types, toxic agents, plant poisons, microscopic evidence, radiological age estimation, and fingerprint patterns covered in the lecture notes.

Ossific Center

A focus of bone formation within cartilage; its appearance helps estimate fetal or neonatal age.

Medullary Cavity

The hollow central cavity within long bones that contains marrow; its extent aids adult age estimation.

Adipocere

Post-mortem waxy fat conversion occurring in moist environments; usually indicates at least ~6 months since death.

Post-mortem Mummification

Desiccation and preservation of tissues in hot, dry conditions, suggesting a post-mortem interval of 3-12 months.

Cut Wound (Incised)

An injury produced by a sharp-edged instrument, characterized by regular, gaping edges and sharply cut surrounding hair.

Stab Wound

A penetrating injury deeper than its length or width on the skin surface, typically caused by a pointed sharp weapon.

Contused (Lacerated) Wound

A tear of tissue from blunt force producing irregular margins often surrounded by bruises and abrasions.

Abrasions

Superficial removal of epidermis produced by friction or scraping; may display patterned marks.

Bruise (Contusion)

Bleeding into soft tissue from blunt trauma without surface break, showing discoloration that changes with time.

Fissure Fracture

A linear crack in bone without displacement of fragments.

Depressed Fracture

Inward displacement of a bone segment, common in skull injuries from localized blunt force.

Cut Depressed Fracture

Skull fracture where a sharp heavy weapon drives bone inward, producing regular edges externally and depression internally.

Pathological Intracerebral Hemorrhage

Spontaneous bleeding within brain parenchyma, often hypertensive, starting deep and not reaching cortical surface.

Extradural Hematoma (EDH)

Lens-shaped blood collection between skull and dura mater, classically due to middle meningeal artery injury.

Subdural Hematoma (SDH)

Concavo-convex blood accumulation beneath dura, usually from torn bridging veins.

Ante-mortem Wound

Injury incurred during life, displaying vital reactions like gaping, bleeding or bruising.

Post-mortem Wound

Lesion produced after death lacking vitality signs such as hemorrhage or inflammation.

Powder Marks

Soot, burns or tattooing around firearm entry indicating close-range discharge.

Rifled Firearm

Weapon whose barrel has spiral grooves; fires single bullets with spin for accuracy.

Smooth-bore (Non-rifled) Firearm

Gun with un-rifled barrel, e.g., shotgun; fires pellets or slugs.

Cartridge Case Groove

Circumferential recess on base indicating suitability for automatic weapons.

External Wad

Thin (≈1 mm) cardboard disc at shotgun muzzle end, aiding shot retention and estimating firing distance (~3 m travel).

Internal Wad

Felt disc (~1 cm) between powder and shot in shotgun cartridges, acts as piston, travels up to 10 m.

Jacketed Bullet

Projectile whose lead core is enclosed wholly or partly by metal (copper/nickel) to reduce deformation.

Aluminum Phosphide

Solid pesticide tablet that releases toxic phosphine gas on contact with moisture; affects heart, liver, lung.

Atropine

Anticholinergic alkaloid in datura and belladonna causing CNS stimulation then depression and peripheral anti-muscarinic effects.

Hyoscine (Scopolamine)

Alkaloid producing early CNS depression and mild peripheral anti-muscarinic action; present in datura species.

Colocynthin

Active drastic purgative principle of colocynth fruits and seeds, with abortifacient potential.

Strychnine

Convulsant alkaloid from Strychnous nux-vomica seeds causing spinal excitability and tetanic seizures.

Myristicin

Psychoactive oil in nutmeg producing hallucinations at high doses.

Ricin

Potent toxalbumin in castor beans causing hemolysis and multi-organ failure.

Cathinone

CNS stimulant and hallucinogen found in khat leaves.

Tetrahydrocannabinol (THC)

Psychoactive cannabinoid responsible for cannabis effects.

Methamphetamine (Crystal Meth)

Potent CNS stimulant smoked as ice; chronic use leads to severe dental caries (“meth mouth”).

Lysergic Acid Diethylamide (LSD)

Potent hallucinogen causing psychedelic experiences even at microgram doses.

Mescaline

Psychedelic alkaloid from peyote cactus producing visual hallucinations.

Digitalis (Digoxin)

Cardiac glycoside from Digitalis purpura plant; therapeutic in low doses, cardiotoxic in overdose.

Amanita Muscaria

Mushroom containing muscarine and other toxins; may cause cholinergic symptoms and hallucinations.

Finger Nail Abrasion

Semilunar superficial scratch produced by fingernails, often around mouth/nose in smothering cases.

Smothering

Mechanical asphyxia from external obstruction of mouth and nose, e.g., by hand or pillow.

Throttling

Manual strangulation producing bruises/abrasions at neck and base of mouth, plus hyoid injury.

Ligature Strangulation

Asphyxia from tightened cord around neck with nearly horizontal mark and underlying bruising.

Hanging

Suspension of body by neck constriction due to a ligature where body weight acts as constricting force.

Washerwoman’s Skin

Wrinkling and pallor of hands/feet after ~24 h immersion, aiding estimation of drowning interval.

Peeling Epidermis (Skin Slippage)

Post-mortem change after ~2 weeks water immersion revealing dermis; helps estimate time since drowning.

Cachexia from Caustic Stricture

Chronic wasting due to esophageal narrowing after alkaline corrosive ingestion.

Corrosive Alkaline Poisoning

Damage from substances like caustic potash causing gray esophageal/stomach burns and later strictures.

Phenol Poisoning

Carbolic acid ingestion causing thickened gastric mucosa with superficial ulcers and respiratory center depression.

Cocaine Septal Perforation

Round nasal septum hole produced by chronic cocaine sniffing and irritant adulterants.

Atropa Belladonna

Deadly nightshade plant containing atropine; all parts toxic with anticholinergic and hallucinogenic effects.

Datura Stramonium Seeds

Black kidney-shaped, mammillated seeds rich in atropine/scopolamine; toxic anticholinergic hallucinogen.

Castor Oil Seeds

Mottled shiny beans containing purgative oil and deadly ricin.

Cotton Fiber

Flat ribbon-shaped vegetable fiber with twists; common textile evidence.

Linen Fiber

Jointed, bamboo-shaped bast fiber running in bundles; refractile under microscope.

Silk Fiber

Smooth, regular protein filament appearing shiny and uniformly thick microscopically.

Wool Fiber

Irregular protein fiber with imbricated scales and wide medulla, from sheep fleece.

Sharply Cut Hair Tip

Indicates slicing by sharp instrument, often around incised scalp wounds.

Crushed Hair Tip

Shows blunt force impact, associated with contused wounds.

Human Hair Shaft

Regular cuticle, broad cortex (⅔ diameter), thin interrupted or absent medulla (≤⅓ diameter).

Animal Hair Shaft

Scaled multi-layered cuticle, narrow cortex (⅓), thick continuous medulla (⅔).

Healthy Hair Root

Rounded root with sheath indicating forcible pulling, supportive of struggle.

Atrophied Hair Root

Shrunken root without sheath; hair lost naturally.

Arch Fingerprint

Pattern where ridges enter one side, rise in center, exit opposite; lacks deltas.

Loop Fingerprint

Ridge flow entering and exiting same side with one delta; most common pattern.

Whorl Fingerprint

Circular/spiral ridge pattern with two deltas.

Epiphyseal Line

Cartilage growth plate whose state (open/closed) on X-ray indicates skeletal age.

Bone Age ≥20 Years (Wrist)

Complete fusion of distal ulna/radius epiphyses and metacarpal heads on hand X-ray.

Bone Age ≤18 Years (Wrist)

Visible epiphyseal lines at distal ulna/radius and metacarpal heads on hand X-ray.

Bone Age ≥21 Years (Knee)

Fusion of distal femur and proximal tibia/fibula epiphyses.

Dental Cast Age ≥12 Years

Presence of erupted second permanent molars.

Dental Cast Age 18 Years+

Eruption of third molars (wisdom teeth).

Diffuse Subendocardial Hemorrhage

Widespread bleeding beneath heart endocardium from trauma, burns, hemorrhage or toxins.

Submucous Laryngeal Contusions

Bruises under mucosa typically from throttling attempts.

Brain Laceration

Tear of brain tissue causing fatal intracranial injury, e.g., from penetrating iron bar.

Septic Skull Fracture

Bone break with infection signs (bone erosion) indicating survival weeks after injury.

Fibrous Membrane Healing

Formation over old depressed skull defect, evidence of long-term survival and surgical decompression.

Powder Tattooing

Embedded unburnt powder grains causing punctate abrasions around bullet entry; indicates close range.

Muzzle Imprint

Abraded contusion replicating firearm barrel end, seen in hard-contact gunshot wounds.

Shotgun Dispersion Pattern

Central defect with surrounding multiple pellet holes increasing with distance.

External Signs of Asphyxia

Include petechiae, congestion, cyanosis, subconjunctival hemorrhage, often seen in strangulation or drowning.

Tardieu Spots

Subpleural or subepicardial petechiae from raised venous pressure in asphyxia.

Battle’s Sign

Post-auricular bruise suggesting basilar skull fracture.

Raccoon Eyes

Periorbital ecchymosis linked to anterior cranial base fracture.

Pond Fracture

Depressed, shallow indentation of infant skull from plasticity.

Diastatic Fracture

Separation along skull suture in children or adults with raised intracranial pressure.

Infanticide by Smothering

Homicide of infant via airway obstruction, evidenced by fingernail abrasions around mouth/nose.

Fingerprints – Individualization

Unique ridge patterns enable personal identification; unaltered throughout life.