Forensic Pathology — MCQs

Forensic Pathology Indian Medical PG Practice Questions and MCQs

Question 361: What is the first external sign of decomposition of a dead body?

A. Decomposition of liver and intestine
B. Greenish discolouration over right iliac fossa (Correct Answer)
C. Greenish discolouration over dependent parts
D. Blood stained froth from mouth

Explanation: ***Greenish discolouration over right iliac fossa*** - The **first external sign of decomposition** is typically a **greenish discoloration** that appears over the **right iliac fossa**. - This occurs due to the breakdown of **hemoglobin** by bacteria, particularly *Clostridium perfringens*, in the **cecum**, which is located in this region. - It typically appears **12-24 hours after death** under normal environmental conditions. *Decomposition of liver and intestine* - While internal organs like the liver and intestine do decompose, their decomposition is an **internal process** and not the **first external sign**. - Internal putrefaction precedes external signs but is not visually observable from the exterior initially. *Greenish discolouration over dependent parts* - Greenish discolouration over dependent parts represents a **later stage of decomposition** when putrefactive changes spread throughout the body. - This occurs after the initial greenish discoloration in the right iliac fossa as bacterial action and gases spread from the intestines to other body regions. - This is NOT the first external sign but rather a progression of decomposition. *Blood stained froth from mouth* - **Blood-stained froth from the mouth** can be seen in various conditions, such as **drowning**, **pulmonary edema**, or certain types of poisoning, but it is not related to decomposition. - This finding is more indicative of the cause of death or agonal/perimortem changes rather than postmortem decomposition.

Question 362: What substance is measured in the vitreous humor to estimate the time since death?

A. Sodium
B. Potassium (Correct Answer)
C. Proteins
D. Chloride

Explanation: ***Potassium*** - **Potassium** concentration in the vitreous humor increases predictably after death due to the breakdown of cellular membranes and passive diffusion from cells. - This consistent post-mortem rise makes it a reliable marker for estimating the **post-mortem interval** (PMI) or time since death. *Sodium* - While sodium is present in the vitreous humor, its post-mortem changes are not as consistent or predictable as potassium for estimating the **time since death**. - Sodium levels tend to decrease slightly after death, but this decline is influenced by various factors and is less reliable for **PMI determination**. *Proteins* - **Proteins** are generally stable in the vitreous humor for some time post-mortem, but their levels do not show a consistent or predictable change that can be used to accurately estimate the **time since death**. - Measuring protein levels is more useful in assessing specific eye pathologies rather than **PMI**. *Chloride* - **Chloride** concentrations in the vitreous humor exhibit post-mortem changes, but like sodium, they are not as precise or reliable as potassium for estimating the **post-mortem interval**. - Its diffusion out of the vitreous humor can be more variable and less consistently linear than potassium's influx.

Question 363: Which feature differentiates antemortem bruises from postmortem bruises?

A. Well-defined margins
B. Capillary rupture with extravasation of blood
C. Presence of yellow color (Correct Answer)
D. Gaping

Explanation: ***Presence of yellow color*** - **Yellow coloration** indicates the breakdown of hemoglobin into **bilirubin** and occurs due to vital reactions in antemortem bruises. - This change is a sign of **healing and metabolism**, which cannot happen in a postmortem state. *Well-defined margins* - The definition of margins in a bruise is not a reliable differentiator, as both antemortem and postmortem bruises can have varying margin characteristics depending on the force and tissue type. - **Well-defined margins** can be seen in both, especially in cases of direct impact or specific tissue types. *Capillary rupture with extravasation of blood* - This is a fundamental characteristic of **all bruises**, whether antemortem or postmortem, as it describes the underlying mechanism of blood leaking from damaged vessels. - The difference lies in the body's reaction to this extravasation, not the initial event itself. *Gaping* - Gaping is typically associated with **lacerations or incisions** where the tissue is separated, rather than just a bruise. - While significant trauma can accompany bruising, gaping is not a defining characteristic that differentiates purely antemortem from postmortem bruises.

Question 364: Flotation of a body in water is due to what?

A. Flesh being eaten by fishes
B. Water logging of body
C. Presence of gases (Correct Answer)
D. All of the above

Explanation: **Presence of gases** - **Decomposition** of a body after death leads to the production of various gases (such as methane, hydrogen sulfide, carbon dioxide, and ammonia) by bacteria. - These gases accumulate in body cavities, particularly the abdomen and chest, causing the body to **swell** and its overall **density to decrease**, eventually becoming less dense than water, leading to flotation. *Flesh being eaten by fishes* - While marine life may consume tissue, this process primarily involves the **removal of mass** and would tend to *reduce* buoyancy rather than directly cause flotation. - It would also likely lead to parts of the body separating and sinking unless significant gas production is also occurring. *Water logging of body* - **Water logging**, or the absorption of water into tissues, generally **increases the body's density**, making it *more likely to sink* rather than float. - This process is counteracted by gas production during decomposition, which is the primary factor for flotation. *All of the above* - This option is incorrect because **gas presence is the primary mechanism** for a body to float due to decomposition, while the other proposed factors either don't cause flotation or would actively hinder it.

Question 365: White lathery froth is seen in deaths due to:

A. Drowning (Correct Answer)
B. Hanging
C. Mineral acid poisoning
D. Organophosphate poisoning

Explanation: ***Drowning*** - The characteristic **white lathery froth** (called **foam cone** or **mushroom froth**) appears at the mouth and nostrils due to the mixing of water, mucus, and air in the airways, often churned during respiratory efforts. - This froth is a strong indicator of **drowning**, although not always definitive of its cause. *Hanging* - Deaths due to hanging typically result from **asphyxia** due to airway obstruction or cerebral ischemia due to carotid artery compression, and do not usually involve froth formation. - While sometimes there may be some oral secretions, it is not the classic lathery, persistent foam seen in drowning. *Organophosphate poisoning* - Organophosphate poisoning causes **cholinergic crisis**, leading to excessive secretions like salivation, lacrimation, and bronchorrhea. - The secretions are usually watery to frothy, but not typically the voluminous, stable, white lathery froth seen in drowning. *Mineral acid poisoning* - Ingestion of mineral acids causes severe **corrosion** and **necrosis** of the gastrointestinal tract and airways, leading to difficulty breathing and potential laryngeal edema. - Froth is not a characteristic finding; instead, there may be **burns** around the mouth and pharynx, and signs of internal visceral damage.

Question 366: After death, body temperature normally falls due to cessation of metabolic heat production (algor mortis). Which of the following conditions is least likely to affect the normal post-mortem cooling process?

A. Sun-stroke
B. Septicemia
C. Tetanus
D. Frost-bite (Correct Answer)

Explanation: ***Frost-bite*** - **Frost-bite** causes localized tissue damage due to freezing, but it does not significantly alter the overall core body temperature at the time of death or the subsequent rate of **algor mortis**. - As a localized injury, its impact on the systemic **metabolic heat production** and dissipation after death is minimal compared to conditions affecting the entire body's thermal regulation. *Sun-stroke* - **Sun-stroke** (heatstroke) results in a dangerously high body temperature, meaning the body starts cooling from a much higher initial temperature. - This elevated initial temperature would therefore prolong the time it takes for the body to reach ambient temperature after death, thus affecting the **normal post-mortem cooling process**. *Septicemia* - **Septicemia** (sepsis) is a severe systemic infection that often causes **fever** and an elevated body temperature. - Higher initial body temperature due to infection would cause a slower than normal rate of cooling post-mortem, as the body has more heat to dissipate. *Tetanus* - **Tetanus** is characterized by severe muscle spasms and rigidity, which are highly **exothermic processes** and can lead to a significant increase in body temperature (hyperthermia). - This elevated initial body temperature at death would alter the normal cooling curve, extending the time to reach ambient temperature.

Question 367: Which of the following conditions is associated with postmortem caloricity?

A. Salicylate poisoning as a cause of postmortem caloricity
B. Sepsis/severe infection as a cause of postmortem caloricity (Correct Answer)
C. Strychnine poisoning as a cause of postmortem caloricity
D. Hyperthyroidism as a cause of postmortem caloricity

Explanation: ***Sepsis/severe infection as a cause of postmortem caloricity*** - **Sepsis and severe infections** are the **most characteristic cause** of postmortem caloricity in forensic medicine - **Bacterial metabolism continues postmortem**, generating heat through ongoing biochemical processes - The **inflammatory cascade** and bacterial toxins create a hypermetabolic state that persists after death - This is considered the **classic and most frequently encountered** cause in forensic practice - Temperature rise can be **substantial and sustained** (up to 2-3°C elevation) *Salicylate poisoning as a cause of postmortem caloricity* - Salicylates cause **uncoupling of oxidative phosphorylation**, leading to heat production - While this can cause postmortem caloricity, it is **less commonly encountered** than sepsis in forensic practice - The effect is present but **less pronounced and sustained** compared to ongoing bacterial metabolism *Strychnine poisoning as a cause of postmortem caloricity* - Strychnine causes **violent muscular contractions and convulsions** that generate significant heat before death - Can contribute to postmortem caloricity, but is **less characteristic** than sepsis - The primary forensic finding is **intense rigor mortis** rather than sustained temperature elevation - **Less frequently seen** as the predominant cause compared to infectious processes *Hyperthyroidism as a cause of postmortem caloricity* - Hyperthyroidism increases basal metabolic rate, but **metabolic processes cease rapidly** after death - **Thyroid storm** may cause extreme hyperthermia pre-mortem, but does not typically produce **active postmortem temperature rise** - **Not a recognized cause** of true postmortem caloricity in standard forensic medicine literature

Question 368: One of the following is a definite sign of death due to drowning:

A. Sand and mud in the mouth or nostrils
B. Diatoms in bone marrow (Correct Answer)
C. Fine lathery froth in the mouth or nostrils
D. Washerman's hands and feet

Explanation: ***Diatoms in bone marrow*** - The presence of **diatoms** (unicellular algae) in organs like the **bone marrow** indicates that the individual was alive and inhaling water containing diatoms at the time of submersion. - This finding confirms that the person was **submerged in water while still alive**, making it a definite sign of death due to drowning, as diatoms would have been absorbed into the bloodstream from the lungs. *Sand and mud in the mouth or nostrils* - While suggestive, sand and mud can be found in the mouth or nostrils of a body dumped in water after death, so it's not a **definite sign of drowning**. - This merely indicates exposure to a muddy environment, not necessarily that aspiration occurred while alive. *Fine lathery froth in the mouth or nostrils* - This **fine, white "mushroom of froth"**, known as **"foam cone"** or **"froth cone,"** is often seen in drowning victims, formed by air, mucus, and surfactant. - However, it can also be seen in other conditions such as **pulmonary edema** (e.g., from opioid overdose or cardiac arrest) or severe aspiration, making it a strong but not definite indicator of drowning. *Washerman's hands and feet* - This phenomenon, also known as **"washerwoman's skin"** or **"postmortem wrinkling,"** is the maceration of the skin on the palms and soles due to prolonged immersion in water. - It occurs after death as a result of water absorption by the skin, so it only indicates **prolonged immersion** and not that the person was alive when they entered the water or that drowning was the cause of death.

Question 369: At what temperature (in degrees Celsius) does heat stiffening in muscles occur?

A. 35
B. 45
C. 55
D. 65 (Correct Answer)

Explanation: ***65*** - **Heat stiffening** (cadaveric spasm from heat) occurs at temperatures around **65-75°C**, with onset typically beginning at **65°C**. - This phenomenon is commonly observed in **burned bodies** or bodies exposed to **fire/high heat**. - The mechanism involves **denaturation and coagulation of muscle proteins**, leading to **irreversible contraction** and stiffening. - **Note:** Heat stiffening is **distinct from rigor mortis** (which is a post-mortem biochemical process due to ATP depletion). *35* - **35°C** is close to **normal core body temperature** (37°C), at which muscles function optimally. - This temperature would **not** induce heat stiffening or protein denaturation. *45* - While **45°C** is above normal body temperature, it is insufficient to cause **heat stiffening**. - This temperature may cause **heat injury** or discomfort in living tissue, but does not reach the threshold for **protein coagulation** and **irreversible muscle rigidity**. *55* - At **55°C**, some early protein changes may begin, but **complete heat stiffening** does not occur. - Significant and pronounced **cadaveric spasm from heat** requires temperatures of **65°C or higher**.

Question 370: Dribbling of saliva is a feature associated with which type of hanging?

A. Antemortem hanging (Correct Answer)
B. Strangulation
C. Postmortem hanging
D. Judicial hanging

Explanation: ***Antemortem hanging*** - **Dribbling of saliva** is a classic sign of **vital reaction** in hanging, indicating the person was alive during the event. - It occurs due to pressure applied to the **salivary glands** by the ligature and the victim's inability to swallow, combined with increased salivation. - Other vital signs include **cyanosis of face**, **petechial hemorrhages**, **congestion**, and **bleeding in soft tissues** around the ligature mark. *Strangulation* - While both hanging and strangulation involve neck compression, **strangulation** is applied by external force (manual or ligature) rather than body weight. - Dribbling of saliva is **not a characteristic feature** of strangulation. - Strangulation typically shows more horizontal ligature marks and greater soft tissue injury. *Postmortem hanging* - In **postmortem hanging**, the individual is already deceased before suspension, thus **no vital reactions** like saliva dribbling would occur. - The ligature mark appears **pale, dry, and parchment-like** without underlying tissue hemorrhage or infiltration. - Absence of congestion, petechiae, and other vital signs helps differentiate from antemortem hanging. *Judicial hanging* - **Judicial hanging** is a form of antemortem hanging using the **long drop method** designed to cause instant death by cervical fracture-dislocation. - Death occurs rapidly due to **spinal cord transection** at C2-C3 level (Hangman's fracture). - While technically antemortem, the **rapid death** means classical asphyxial signs like dribbling saliva may be minimal or absent.

Practice by Chapter

Postmortem Changes

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Medicolegal Autopsy

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Death Cause, Mechanism and Manner

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Time Since Death Estimation

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Sudden and Unexpected Deaths

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Injuries and Wound Examination

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Blunt Force Injuries

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Sharp Force Injuries

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Firearm Injuries

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Internal Examination in Autopsy

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Histopathology in Forensic Practice

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Death Certification

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