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Dr. Sumit Seth,is a career diplomat,member of prestigious Indian Foreign Service.He happens to be the youngest post-graduate of Forensic Medicine in India.

Sunday, June 13, 2010

Delhi Pre PG Entrance Exam 2010

Detailed Explanations of Forensic Medicine from "Review Of Forensic Medicine" 3rd Edition,

Paper courtesy DAMS Delhi Academy of Medical Sciences


1. The age of a 15-year old female is best determined by the radio-graph of :

a. Lower end of Radius and Ulna
b. Upper end of Humerus
c. Upper end of Radius and Ulna
d. Xiphisternum

Explanation:

Joints Approximate age of fusion

Shoulder joint 18 years
Elbow joint 16 years
Wrist joint 18 years
Hip joint 17-18 years
Knee joint 18 years
Ankle joint 16-17 years

In Females Fusion occurs 1-2 years earlier*(Except Skull, sutures obliterates earlier in Males)


2. Sodium fluoride is used for preservation:

a. Urine
b. Blood
c. Alcohol
d. Carbonic acid

Explanation:

Preservation of Viscera

1. Stomach and its contents
2. 30 cm small Interline and contents
3. Liver > 500 gms
4. One kidney/Half of each
5. Blood 100 cc (in NaF), (Minimum 10 ml)*
6. Urine > 100 cc–(in Thymol)* [Toulene* is the best preservative for urine examination]

• The best preservative for preservation of viscera is rectified spirit.
• Most commonly used preservative is saturated sodium chloride.

• Rectified spirit is not used in:
– Alcohol
– Phenol
– Phosphorous
– Paraldehyde.

• Formaldehyde is used for preservation of Museum specimens and not for preservation of viscera for toxicological analysis.

• Formalin is 40% formaldehyde.

• NaF should be added to urine, blood, vitreous humor for Alcohol estimation and to samples of
– Cocaine (C)
– Carbon monooxide (C)
– Cyanide (C)

Special Preservation

Heart–Strychnine, Digitalis
Spleen-It is the best organ for Cyanide poisoning
Brain–Alkaloids, organophosphates, volatile organic poisons
Bile–Narcotic drugs, cocaine, methadone, Glutathione, Barbiturates, Tranquilizers
Vitreous–Alcohol, Chloroform
Lung–Gaseous poison, HCN, Alcohol, Chloroform
Bone–Arsenic, Antimony, thallium, Radium
Skin–C/o hypodermic injections (10 cm radius about site with muscle and fat), snake bite
Hair, Nails, Uterus, spinal card–When indicated
CSF–(in 10 mg NaF/ml of fluid) in Alcohol intoxication.
Body Fat—Endrin ,DDT(Organo Chlorines)
Muscle–When internal organs badly putrified

• Viscera is stored at 4°C

• Histopathology specimen is preserved in 10% neutral formalin/95% Alcohol

• Virology specimen  80% Glycerol in Buffer saline.



88. Maximum congestion is seen in:

a. Choking
b. Hanging
c. Strangulation
d. Drowning

Explanation:

Strangulation

• Strangulation is that form of asphyxia which is caused from constriction of the neck by a ligature without suspending the body.

• The mark in strangulation completely encircles the neck transversely, below the thyroid cartilage.

• Doing a post-mortem on a suspected case of strangulation in-situ examination of neck structures is done before opening the skull and the chest

• Most important sign of strangulation is ligature mark.

• Fracture of Thyroid Cartilage is more common in strangulation by ligature.
– Mugging—Homicidal strangulation, by holding the neck in the bend of elbow.
– Bansdola—Strangulation with sticks (Homicidal strangulation)
– Garroting—Strangulation by twisting a lever like a tourniquet, homicidal strangulation.
(Traditionally was practiced in ‘SPAIN’ as a mode of execution.)

Throttling

1. Manual strangulation (always homicidal).
2. Fracture of the hyoid bone in 30-50% cases
• In Hyoid there is inward compression fracture*.
• The periosteum is torn on the outer side.
3. Fracture of the thyroid cartilage and of hyoid bone are usually found in above 40 years

Signs of Asphyxia
• Intense congestion and deep cyanosis of the head and neck is seen in strangulation
• The eyes wide open and pupils dilated
• The tongue swollen and protruded
• Petechial haemorrhages are common into the skin of the eyelids, face, forehead, behind the ears and scalp
• Blood stained froth may escape from the mouth and nostrils and there may be bleeding from nose and ears
• The intima of the carotid artery are not usually damaged
• Fracture of the thyroid cartilage is more common.



89. In freshwater drowning the death occurs within 4-5 minutes of submersion due to
ventricular fibrillation . Which of the following reasons is responsible for this ?

a. Total asphyxia produced due to fresh water
b. Laryngospasm causing vagal inhibition
c. Haemoconcentration of blood caused by the osmotic pressure effect
d. Haemodilution, overloading of heart and haemolysis resulting in release of potassium

Explanation:

Drowning in Fresh Water
• Death in fresh water drowning in comparison to salt water is earlier .
• Drowning in fresh water leads to hemolysis and hemodilution, hyperkalemia and the cause of death is ventricular fibrillation.
• In fresh water drowning, chloride content of the left side of the heart is 50% lower

Drowning in Sea Water
• Due to high salinity of sea water (usually over 3% NaCl), water is drawn from blood into lung tissue, and produces severe pulmonary oedema and hypernatraemia, increase in magnisium ion.
• This causes haemoconcentration, the cause of death is Bradycardia.*
• In sea water drowning, chloride content of the left side of the heart is higher (Gettler’s Test)*.

Gettler’s Chloride test
– to differentiate fresh water drowning from sea water drowning
• Chloride estimation is not of any help after 12 hours
• It is not helpful in
o Putrefaction
o Patent Foramen Ovale
o Drowning in Brackish Water
-- Fresh water drowning, chloride content of the left side of the heart is 50% lower




90. Bevelling of the skull is seen in the:

a. Broad end of the entry point in bullet injury
b. Narrow end of the entry point in bullet injury
c. Exit point of bullet
d. Depressed fracture of the skull

Explanation

Beveling of the skull in bullet injury: The principle which guides the occurrence of beveling is that the bullet produces beveling in the second layer (or exit point).

• In entry wound the beveling is present in inner table of skull
• In exit wound the beveling is present in the outer table of skull


91. All are components of black gun powder blister except:

a. Sulphur
b. Charcoal
c. Potassium nitrate
d. Lead peroxide

Explanation

• Black gun powder–It consists of potassium nitrate 75%, sulphur 10%, and charcoal 15%.
Use of constituent:
• Potassium nitrate—Oxidising agent
[Dermal Nitrate Test/Parrafin Wax test/Diphenyl Amine Test * is done to detect presence of gun Powder on hands of the person who has fired the Gun]
• Sulphur—Increase density by acting as binding agent
• Charcoal—Fuel
[ NB:- FG “Fine Grain” denotes the fineness of Gun Powder particles, moreFs quicker it will burn]


92. When a group of muscles of a dead body were in state of strong contraction
Immediately prior to death and remain so even after death, the condition is termed as:

a. Gas stiffening
b. Rigor mortis
c. Cadaveric spasm
d. Cold stiffening

Cadaveric spasm or Instantaneous Rigor or Cataleptic rigidity*

• In this condition, the muscles that are contracted during life, become stiff and rigid immediately after death, without the stage of primary relaxation.

• It occurs especially in cases of:

A – sudden Asphyxial death
B – injury to the Brain
C – Cerebral hemorrhage
D – Drowning, Di nitro Ortho Cresol posisoning
E – Exhaustion,
F- Fear, Firearm injury.


• This is usually limited to a single group of muscles and frequently involves hands;
• It mainly occurs in voluntary muscles.
• It cannot be produced by any method after death.
• It may be explained on the basis of diminished or exhausted ATP in the affected muscles.
• Rigor mortis simulates cadaveric spasm.


93. Legal age at which foetus is capable of independent existence:

a. 240 days
b. 230 days
c. 220 days
d. 210 days

Viability: Physical ability of a fetus to lead “separate existence”.

• A child is legally viable after 210 day ( 7 × 30 days).
Memory cue--> count down 2-1-0-viable

Signs of Viability

1. Length 35 cm (using Hasse’s rule 7 × 5 = 35 cm).
2. Weight 900 to 1200 gms.
3. Eyelids an open, pupillary membrane disappears.
4. Testies are found at external inguinal ring.
5. Ossification centres appearing at viability.
• Centre for Talus.
• Centre for 2nd and 3rd piece of Sternum.


94. A bullet fired from a gun is not released. It is ejected out with the subsequent shot .
It is known as :

a. Dumbum bullet
b. Rocketing bullet
c. Ricochet bullet
d. Tandem bullet

Bullets

• Bullet is made up of lead.
• The extent of muscle damage by a bullet depends primarily on the velocity.
• Large round bullet causes greater damage to the body.
• A dumdum bullet, so called because tip is chiseled out, is one, which fragments extensively upon striking.
• Express bullet—Bullet in which a hole is present
o Tracer Bullet—Powder in the base so that it burns brightly*
• Incendiary bullets contain phosphorus.
• Souvenier Bullet—When the bullet remains in body for a long period of time is called souvenier bullet. It causes chronic lead poisoning.
• Glance bullet causes gutter fracture.
• Piggyback bullet—when bullet fails to come out from muzzy, this bullet is pushed by another bullet (Tandem bullet). In Tandom cartridge bullets are present in same cartridge which enters the target at different points.


95. Brown—coloured urine is seen in the :

a. Nitric acid poisoning
b. Carbolic acid poisoning
c. Hydrochloric and poising
d. Sulphuric acid poising

In concentrated form Nitric Acid combines with organic matter and produces a yellow discoloration of tissue due to the production of picric acid (xanthoproteic reaction). The stomach is soft, friable and ulcerated and Brownish Discoloration. Perforation of stomach is not common.



96. Which of the following is a non-poisonous snake :
a. Viper
b. Krait
c. Sea snake
d. Rat snake

Explanation:

The Poisonous snakes may be divided into five families:
1. Cortalidae–Pit viper
2. Viperidae (True viper)*–Russel’s viper
3. Elapidae–Cobra and Krait**
4. Hydrophidae–Sea snakes (All sea snakes are poisonous).
5. Colubridae–Boom stangs, Bird snakes.


97. In methyl alcohol poisoning there is CNS depression, cardiac depression and optic
nerve atrophy. These effect are produced due to :

a. Formaldehyde and formic acid
b. Aceldehyde
c. Pyridine
d. Acetic acid


Methanol Poisoning

• Earliest clinical presentation is abdominal cramps
• It causes snow-field vision due to Formaldehyde and Formic acid toxicity of optic nerve
• Severe non-diabetic acidosis in unconscious person is suggestive of Methanol poisoning
• Treatment
• Haemodialysis is the treatment of choice
• Antidote
– Ethanol
– 4-Methyl Pyrazole (Fomipazole)
• Folinic Acid enhances excretion of formic acid.

98. Priapism occurs in :

a. Snake bite
b. Ratti poisoning
c. Cantharides poising
d. Arsenic poisoning

CANTHARIDES

• Spanish fly (blister beetle) is used externally as an irritant, and is commonly popular as an Aphrodisiac.(Reason for Priapism)
- The active principle is cantharidin.
- The Indian fly (beetle) contains about 3% cantharidin.
- Cantharidin is readily absorbed from all surfaces including the skin.


99. Which ofthe following section of IPC are concerned with dowry death :

a. 300`
b. 302
c. 304A
d. 304B

Explanation

Offence Affecting Human Body

Sec 299 to Sec 377
• Sec 299 Culpable Homicide
• Sec 300 Murder
• Sec 302 Punishment of murder/infanticide*
• Sec 304 Culpable Homicide not amounting to murder
• Sec 304 A Causing death by negligence*
• Sec 304 B Dowry Death ( Memory Cue: 304 BBride Burning )

100. A cognizable offence signifies:

a. imprisonment up to 2 year
b. imprisonment up to 5 year
c. Arrest without warrant
d. Fine up to Rs. 10,000