Free forensic medicine MCQ exam model for clinical students

Explanation:

• Gravitational settling of blood → Correct because blood pools in dependent parts after death.

• Rigor mortis → Incorrect because it is muscle stiffening.

• Coagulation of blood → Incorrect because lividity is due to pooling, not clotting.

• Decomposition gases → Incorrect because they cause bloating.

• Muscle stiffening → Incorrect because that describes rigor mortis.

Explanation:

• Dose lethal to 50% of population → Correct because LD₅₀ is a standard toxicity measure.

• Minimum lethal dose → Incorrect because that refers to smallest fatal dose.

• Maximum safe dose → Incorrect because it is therapeutic index related.

• Dose causing toxicity → Incorrect because toxicity may occur below lethal dose.

• Dose causing unconsciousness → Incorrect because it is not the definition of LD₅₀.

Explanation:

• Shock → Correct because fluid loss and burn shock are early major causes of death.

• Pain → Incorrect because it is not a direct cause of death.

• Infection → Incorrect because it is a late cause.

• Asphyxia → Incorrect because it occurs in enclosed fires but not most common.

• Renal failure → Incorrect because it is a late complication.

Explanation:

• Circumstances of death → Correct because manner describes how death occurred (natural, accidental, homicidal, suicidal).

• Cause of death → Incorrect because it is the disease or injury causing death.

• Mechanism of death → Incorrect because it is the physiological derangement.

• Time since death → Incorrect because it estimates postmortem interval.

• Place of death → Incorrect because it is not the definition of manner.

Explanation:

• Rigor mortis → Correct because it is an irreversible postmortem change.

• Cessation of respiration → Incorrect because it may be reversible.

• Cessation of heartbeat → Incorrect because resuscitation may be possible.

• Loss of corneal reflex → Incorrect because it can be absent in coma.

• Pallor → Incorrect because it is non-specific.

Explanation:

• Application of medical knowledge to law → Correct because forensic medicine links medicine with legal investigations and courts.

• Treatment of injuries → Incorrect because this is clinical medicine.

• Prevention of disease → Incorrect because this is public health.

• Study of microorganisms → Incorrect because this is microbiology.

• Drug therapy → Incorrect because this is pharmacology.

Explanation:

• Color changes → Correct because hemoglobin breakdown causes predictable color progression.

• Size of bruise → Incorrect because size varies with force and tissue.

• Shape of bruise → Incorrect because it reflects object shape.

• Location of bruise → Incorrect because it does not indicate age.

• Depth of bruise → Incorrect because it is difficult to assess clinically.

Explanation:

• Bruising of neck → Correct because pressure causes contusions and petechiae.

• Incised wound → Incorrect because it is caused by sharp objects.

• Laceration → Incorrect because it is due to blunt force tearing.

• Stab wound → Incorrect because it is caused by pointed weapons.

• Chop wound → Incorrect because it is caused by heavy sharp weapons.

Explanation:

• Carbon monoxide → Correct because carboxyhemoglobin gives cherry-red color.

• Cyanide → Incorrect because it causes cellular hypoxia without cherry-red color typically.

• Arsenic → Incorrect because it causes GI symptoms.

• Organophosphate → Incorrect because it causes cholinergic symptoms.

• Methanol → Incorrect because it causes metabolic acidosis and blindness.

Explanation:

• Neck and jaw muscles → Correct because rigor mortis starts in small muscles like jaw and neck.

• Lower limbs → Incorrect because rigor reaches them later.

• Upper limbs → Incorrect because they are affected after jaw.

• Trunk muscles → Incorrect because they stiffen later.

• Facial muscles only → Incorrect because jaw and neck are first, not face alone.