Forensic Toxicology — MCQs

Forensic Toxicology Indian Medical PG Practice Questions and MCQs

Question 771: Which of the following toxins will lead to the appearance of gastric mucosa as shown in the image?

A. Iron oxide
B. Arsenic trioxide
C. Mercury
D. Copper sulfate (Correct Answer)

Explanation: ***Copper sulfate*** - The image shows a gastric mucosa with a **bluish-green discoloration**, which is highly characteristic of ingestion of **copper sulfate**. - Copper sulfate is a **corrosive agent** that causes direct chemical injury, leading to significant mucosal damage and this distinct color change upon contact. *Iron oxide* - Ingestion of iron compounds primarily causes direct local **gastrointestinal irritation** and systemic toxicity, but does not result in a bluish-green discoloration of the gastric mucosa. - Iron poisoning typically leads to symptoms like **vomiting**, **diarrhea**, and potentially **hemorrhage**, but not this specific color change. *Arsenic trioxide* - Arsenic poisoning, while causing severe gastrointestinal symptoms such as **vomiting**, **diarrhea**, and **abdominal pain**, does not produce a characteristic bluish-green staining of the gastric mucosa. - Prolonged exposure can lead to **multi-organ failure** and **neurological symptoms**, but the visual appearance in the image is not consistent. *Mercury* - Mercury poisoning can cause severe **gastrointestinal inflammation** and necrosis due to its corrosive effects, particularly with salts like mercuric chloride. - However, it does not typically lead to the distinct **bluish-green discoloration** seen in the image, which is pathognomonic for copper sulfate ingestion.

Question 772: The image given below shows:

A. Castor seeds (Correct Answer)
B. Croton seeds
C. Marking nut
D. Jequirity seeds

Explanation: ***Castor seeds*** - The image displays seeds with a characteristic **mottled appearance** and a prominent **caruncle**, which are key features of **castor seeds** (Ricinus communis). - Castor seeds contain **ricin**, a highly toxic protein that can cause severe gastrointestinal symptoms, hemorrhage, and multi-organ failure if ingested. *Croton seeds* - Croton seeds (Croton tiglium) are typically **smaller, glossy, and more uniformly shaped** compared to the seeds in the image. - While also toxic, containing phorbol esters causing severe purgation, their morphological features are distinct from those shown. *Marking nut* - Marking nuts (Semecarpus anacardium) are typically **heart-shaped or kidney-shaped**, black, and have an oily resin. - They are known for causing vesicant dermatitis and are used in traditional medicine, but their appearance differs from the seeds in the image. *Jequirity seeds* - Jequirity seeds (Abrus precatorius) are typically **small, bright red with a black spot**, resembling a ladybird beetle. - They contain **abrin**, another toxic protein similar to ricin, but their distinctive coloration makes them easily distinguishable from castor seeds.

Question 773: The seeds shown in the image below have which toxin? (Recent NEET Pattern 2016-17)

A. Ricin
B. Abrin (Correct Answer)
C. Calotoxin
D. Plumbagin

Explanation: ***Abrin*** - The seeds shown in the image are characteristic of **Rosary Pea (Abrus precatorius)**, known for their bright red color with a black spot. - These seeds contain the potent **ribosome-inactivating protein toxin** called abrin. *Ricin* - **Ricin** is a toxin derived from the seeds of the **castor oil plant (Ricinus communis)**, which look different from the seeds pictured. - Castor seeds are typically mottled brown, black, and white, not bright red with a black spot. *Calotoxin* - **Calotoxin** is a cardiac glycoside found in plants like **Calotropis (milkweed)**. - The seeds of Calotropis are flat, brown, and have a tuft of silky hair, which is completely different from the seeds shown. *Plumbagin* - **Plumbagin** is a naphthoquinone compound found in plants like **Plumbago zeylanica**. - This compound is not associated with the red and black seeds depicted in the image.

Question 774: The following image shows:

A. Castor seeds (Correct Answer)
B. Croton seeds
C. Marking nut
D. Betel nut

Explanation: ***Castor seeds*** - The image displays several seeds that are **oval-shaped** with a **mottled brown and black pattern**, a characteristic appearance of **castor beans**. - Castor seeds (Ricinus communis) contain **ricin**, a highly toxic protein that can cause severe gastrointestinal symptoms, hemorrhage, and multi-organ failure if ingested. *Croton seeds* - Croton seeds are generally smaller and more uniformly black or dark brown, lacking the distinct **marbled appearance** of castor seeds. - While also toxic, they contain **croton oil**, which acts as a powerful purgative and an irritant. *Marking nut* - Marking nut (Semecarpus anacardium) is typically **heart-shaped or kidney-shaped** and black, which is visually distinct from the seeds shown. - It contains **bhilawanol**, an irritant resin that can cause severe blistering and skin reactions upon contact. *Betel nut* - Betel nuts are usually **round or oval** and range from reddish-brown to dark brown, often with a fibrous texture, but do not exhibit the **mottled pattern** seen in the image. - Chewed for its **mild stimulant effect**, it is associated with oral submucous fibrosis and oral cancer with chronic use.

Question 775: All are true about the poisoning caused by following plant except: (Recent NEET Pattern 2016-17)

A. Toxic principle is ricin
B. Fatal dose is 1 mg/kg body weight
C. Urine alkalization (Correct Answer)
D. Opisthotonus

Explanation: ***Urine alkalization*** - There is **no specific role** for **urine alkalization** in the management of castor bean (ricin) poisoning. - Management is primarily **supportive**, including gastrointestinal decontamination, fluid resuscitation, and symptomatic treatment. - Urine alkalization is used in salicylate or barbiturate poisoning, **not in ricin poisoning**. *Toxic principle is ricin* - The castor bean plant (**Ricinus communis**) contains **ricin**, a highly potent **lectin** and protein synthesis inhibitor. - Ricin causes severe **cellular toxicity** leading to gastrointestinal, hepatic, renal, and systemic manifestations. - This is a **TRUE statement**. *Fatal dose is 1 mg/kg body weight* - The **fatal dose of ricin** is approximately **1 mg/kg body weight** when ingested. - Ingestion of even **1-3 chewed castor beans** can be fatal in adults, making it one of the most poisonous plants. - This is a **TRUE statement**. *Opisthotonus* - **Opisthotonus** (backward arching due to severe muscle spasm) can occur in **severe cases** of ricin poisoning as a neurological manifestation. - While more classically associated with **tetanus** or **strychnine poisoning**, severe ricin toxicity can cause convulsions and opisthotonus. - This is considered a **TRUE statement** in the context of severe ricin poisoning.

Question 776: What is the type of venom of the snake shown below? (Recent NEET Pattern 2016-17)

A. Vasculotoxic
B. Neurotoxic
C. Vasculotoxic and hemotoxic (Correct Answer)
D. Hemotoxic

Explanation: ***Vasculotoxic and hemotoxic*** - The image displays a **Russell's viper** (*Daboia russelii*), identified by its characteristic chain of three prominent, dark, oval, or rhomboidal spots. - The venom of the Russell's viper is primarily **vasculotoxic** (affecting blood vessels) and **hemotoxic** (affecting blood components), causing symptoms like local pain, swelling, blistering, and coagulopathy leading to bleeding. *Vasculotoxic* - While Russell's viper venom is indeed vasculotoxic, this option is incomplete as it lacks the hemotoxic component which is also significant. - **Vasculotoxicity** leads to damage to blood vessel walls, causing leakage and local tissue damage. *Neurotoxic* - Neurotoxic venom primarily affects the nervous system, leading to paralysis and respiratory failure, which is characteristic of snakes like **cobras** and **kraits**. - The Russell's viper venom does not have significant neurotoxic effects in humans. *Hemotoxic* - While Russell's viper venom is hemotoxic, this option is incomplete as it misses the **vasculotoxic** effects that are a crucial part of its pathology. - **Hemotoxicity** impacts blood clotting factors and red blood cells, leading to internal and external bleeding.

Question 777: What is the nature of the venom produced by the snake shown below? (Recent NEET Pattern 2016-17)

A. Vasculotoxic
B. Neurotoxic (Correct Answer)
C. Vasculotoxic and hemotoxic
D. Hemotoxic

Explanation: ***Neurotoxic*** - The image shows a **Banded Krait** (*Bungarus fasciatus*), identified by its distinctive alternating bands of yellow and black. - Kraits belong to the **Elapidae family** (along with cobras and coral snakes) and produce **predominantly neurotoxic venom**. - The venom contains **α-bungarotoxin** and **β-bungarotoxin**, which block neuromuscular transmission causing **descending paralysis**. - **Clinical features** include ptosis, ophthalmoplegia, paralysis, respiratory failure, and minimal local swelling - classic neurotoxic presentation. - In forensic medicine classification, kraits are categorized as **neurotoxic snakes**, unlike vipers which are hemotoxic/vasculotoxic. *Vasculotoxic and hemotoxic* - This describes **viper venom** (Russell's viper, Saw-scaled viper), not krait venom. - Vipers cause **extensive local tissue damage, bleeding, coagulopathy**, and necrosis - features NOT seen with krait bites. - Krait bites show **minimal local effects** with predominantly systemic neurotoxic manifestations. *Vasculotoxic* - Vasculotoxic effects (endothelial damage, vascular permeability) are characteristic of **viper envenomation**, not kraits. - Banded Krait venom acts primarily on the **nervous system**, not blood vessels. *Hemotoxic* - Hemotoxic effects (hemolysis, coagulopathy, thrombocytopenia) are features of **viper venom**. - Kraits produce **neurotoxic venom** that causes paralysis without significant hematological effects. - The absence of bleeding and coagulation defects helps differentiate krait from viper bites clinically.

Question 778: Which of the following is not true about the poisoning caused by seeds shown below?

A. Opisthotonos
B. Uncrushed seeds will not lead to poisoning
C. Toxin potentiates neurotransmitter glycine effect at pre-synaptic receptor (Correct Answer)
D. Post mortem caloricity

Explanation: ***Toxin potentiates neurotransmitter glycine effect at pre-synaptic receptor*** - This statement is **incorrect** and is the right answer to this "NOT true" question. - Strychnine, the toxin found in Nux vomica seeds, is a **glycine antagonist** that competitively inhibits glycine receptors in the spinal cord and brainstem. - By blocking glycine's inhibitory effect on motor neurons, it leads to **uncontrolled muscle contractions** and characteristic convulsive spasms. *Opisthotonos* - This is the **characteristic posture** seen in strychnine poisoning, characterized by **backward arching of the body** due to severe extensor muscle spasms. - It results from the strong contraction of **extensor muscles** (particularly back and neck muscles), predominantly due to uninhibited motor neuron activity. - The body forms a rigid arc with only the head and heels touching the surface. *Uncrushed seeds will not lead to poisoning* - The **strychnine** content is within the endosperm of the seed, and the outer seed coat (testa) is very hard and indigestible. - For the toxin to be absorbed and cause poisoning, the seeds typically need to be **crushed or chewed**, breaking down the hard outer layer. - Intact seeds may pass through the GI tract without causing toxicity. *Post mortem caloricity* - This refers to the **rise in body temperature** after death, which is a characteristic finding in cases of strychnine poisoning. - The sustained and violent muscle spasms before death generate significant heat through increased metabolic activity. - Temperature can persist and even increase post-mortem due to continued metabolic processes in dying cells and the insulating effect of the body.

Question 779: Which of the following is not true about the symptoms experienced after consumption of the poison from the plant shown below?

A. Dryness of the mouth
B. Urine retention
C. Sour taste (Correct Answer)
D. Dilated pupils

Explanation: ***Sour taste*** - The plant shown is likely a species of **Datura**, also known as Jimsonweed or thorn apple, which contains **anticholinergic alkaloids** like atropine and scopolamine. - These alkaloids cause an array of symptoms consistent with **anticholinergic toxidrome**, but **sour taste** is not a typical manifestation of anticholinergic poisoning. *Dryness of the mouth* - **Atropine** and **scopolamine**, present in Datura, block muscarinic acetylcholine receptors, leading to decreased salivary gland secretions. - This results in a profound sensation of **dry mouth** (xerostomia), a classic anticholinergic symptom. *Urine retention* - Anticholinergic agents like those in Datura inhibit the contraction of the **detrusor muscle** of the bladder and promote contraction of the urethral sphincter. - This combination impairs bladder emptying and causes **urinary retention**, another hallmark of anticholinergic poisoning. *Dilated pupils* - Anticholinergic compounds block the M3 muscarinic receptors in the **iris sphincter muscle**, preventing constriction. - This leads to **mydriasis** (dilated pupils), which is a characteristic sign often summarized as "blind as a bat" in the anticholinergic toxidrome.

Question 780: The seeds of the plant shown below resemble which of the following? (Recent NEET Pattern 2016-17)

A. Semecarpus anacardium
B. Capsicum
C. Ricinus communis (Correct Answer)
D. Nerium odorum

Explanation: ***Ricinus communis*** - The image displays a **spiny fruit** containing numerous **brown, mottled seeds** that are characteristic of the *Ricinus communis* plant, also known as the **castor bean plant**. - **Castor seeds** are highly toxic due to the presence of **ricin**, a potent protein toxin. *Semecarpus anacardium* - This plant, commonly known as **marking nut** or **Bhallataka**, produces an **oval-shaped, black nut** with a cup-shaped fleshy receptacle. - Its seeds are generally **kidney-shaped** and black, differing from the seeds shown in the image. *Capsicum* - *Capsicum* refers to **chili peppers**, which produce berries containing small, **flat, pale yellow or white seeds**. - The seeds in the image are **dark brown and irregular**, not consistent with *Capsicum* seeds. *Nerium odorum* - *Nerium odorum* is a species of **oleander**, a highly toxic plant whose seeds are typically found in **long, narrow follicles**. - The seeds are usually **light brown to reddish-brown**, often with hairy tufts, which do not match the appearance of the seeds in the image.

Practice by Chapter

General Principles of Toxicology

Practice Questions

Corrosive Poisons

Practice Questions

Metallic Poisons

Practice Questions

Non-Metallic Poisons

Practice Questions

Organic Irritant Poisons

Practice Questions

Neurotic Poisons

Practice Questions

Cardiac Poisons

Practice Questions

Asphyxiant Poisons

Practice Questions

Food Poisoning

Practice Questions

Drug Abuse and Dependence

Practice Questions

Analytical Toxicology Methods

Practice Questions

Interpretation of Toxicology Results

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free