Dirt collar or grease collar is seen in which type of wound?
Disputed maternity can be solved by using the following tests, EXCEPT:
Which of the following sources provides the highest yield and most reliable samples for DNA fingerprinting?
In medical negligence cases, what is the primary role of the plaintiff?
Which of the following is NOT considered a grievous injury?
What substance is measured in the vitreous humor to estimate the time since death?
In a case of hanging, the ligature marks on the neck are an example of which type of injury?
What is the effect of strychnos nux vomica poisoning on a patient's consciousness?
The odour of cyanide is similar to?
Which of the following is true about cadaveric spasm?
NEET-PG 2012 - Forensic Medicine NEET-PG Practice Questions and MCQs
Question 11: Dirt collar or grease collar is seen in which type of wound?
- A. Lacerated wound
- B. Firearm entry wound (Correct Answer)
- C. Stab wound
- D. Punctured wound by sharp weapon
Explanation: ***Firearm entry wound*** - A **dirt collar** or **grease collar** is a characteristic finding in a **firearm entry wound**, caused by the wiping off of dirt, lubricant, and other residues from the projectile as it penetrates the skin. - This reddish-brown to black ring around the wound entrance is a crucial indicator of the **direction of fire** and the nature of the injury. *Punctured wound by sharp weapon* - This type of wound is characterized by a small, deep opening caused by a sharp, pointed object, and typically lacks the **residue collection** that forms a dirt or grease collar. - While there may be some contamination, it does not form a distinct, recognizable collar as seen with firearm projectiles. *Lacerated wound* - A lacerated wound is an irregular tear in the skin caused by a blunt force trauma, characterized by **jagged edges** and often bridging tissue. - These wounds are not typically associated with a "dirt collar" as they are due to tearing rather than a projectile wiping off material. *Stab wound* - A stab wound is caused by a sharp object penetrating the skin, with depth greater than width, and is defined by its clean-cut edges. - While there might be some *foreign material* deposited, it does not present as a distinct **grease or dirt collar** because the mechanism of injury (cutting/stabbing) differs from that of a bullet.
Question 12: Disputed maternity can be solved by using the following tests, EXCEPT:
- A. Blood grouping
- B. HLA typing
- C. DNA fingerprinting
- D. Precipitin test (Correct Answer)
Explanation: ***Precipitin test*** - The **precipitin test** is used to determine the origin of a **blood sample**, specifically whether it is **human or animal blood**, by detecting species-specific proteins. It is not used for assessing maternity. - This test is primarily employed in **forensic serology** to differentiate between blood from different animal species, making it irrelevant for paternity or maternity disputes. *Blood grouping* - **Blood grouping** (e.g., ABO and Rh systems) can be used to **exclude paternity or maternity** by comparing the blood types of the child, mother, and alleged father. - If the child's blood type is incompatible with the alleged parents based on Mendelian inheritance, one or both can be excluded. *HLA typing* - **HLA typing** (Human Leukocyte Antigen) is a more powerful genetic marker system than ABO/Rh for determining paternity or maternity. - It involves analyzing highly polymorphic genes on chromosome 6 that encode cell surface proteins, providing a more definitive means of **inclusion or exclusion**. *DNA fingerprinting* - **DNA fingerprinting** (also known as **DNA profiling**) is the **most accurate and widely accepted method** for resolving paternity and maternity disputes. - It analyzes highly variable regions of DNA unique to each individual, providing a statistically strong basis for **inclusion or exclusion** by comparing genetic profiles.
Question 13: Which of the following sources provides the highest yield and most reliable samples for DNA fingerprinting?
- A. Saliva
- B. Tooth
- C. Buccal mucosa
- D. Blood (Correct Answer)
Explanation: ***Blood*** - **Blood** provides a high concentration of **nucleated cells** (e.g., white blood cells), yielding abundant and high-quality DNA. - The DNA obtained from blood is typically well-preserved and less prone to degradation or contamination compared to other sources. *Saliva* - While saliva contains DNA from **buccal epithelial cells** and white blood cells, its DNA yield can be lower and more variable due to mucous and bacterial contamination. - DNA from saliva may be more subject to degradation, especially if not collected and stored properly. *Tooth* - **Teeth** can be a good source of DNA, particularly from the **pulp**, but extraction can be challenging and destructive. - The DNA yield varies depending on the tooth's condition and the extraction method, and it is generally reserved for situations where other sources are unavailable or severely degraded. *Buccal mucosa* - **Buccal mucosa** swabs are a common and non-invasive source of DNA from **epithelial cells**. - While suitable for many applications, the DNA yield can be lower than blood, and the sample may be more susceptible to surface contamination.
Question 14: In medical negligence cases, what is the primary role of the plaintiff?
- A. Files case in civil court (Correct Answer)
- B. Acts as defender
- C. Gives judgement
- D. Issues summons to defendant
Explanation: ***Files case in civil court*** - The **plaintiff** is the party who initiates a lawsuit, claiming to have been harmed by the actions of another party. - In medical negligence cases, this typically involves someone who alleges injury due to substandard medical care and seeks **compensation** through the legal system. - Filing the case in civil court is the **primary and defining role** of the plaintiff. *Acts as defender* - The **defender** (or defendant) is the party against whom a lawsuit is brought, and they are responsible for responding to the plaintiff's claims. - In medical negligence, the healthcare provider accused of negligence would be the defender. *Gives judgement* - Giving judgment is the function of the **court** or judge and is a neutral adjudication of the facts and application of the law. - The plaintiff's role is to present their case and evidence to persuade the court, not to issue the final decision. *Issues summons to defendant* - Issuing summons is a **court function**, not the plaintiff's role. - The court issues summons after the plaintiff files the case, directing the defendant to appear and respond to the allegations.
Question 15: Which of the following is NOT considered a grievous injury?
- A. Multiple facial scars
- B. Femur fracture
- C. Emasculation injury
- D. Breast contusion (Correct Answer)
Explanation: ***Breast contusion*** - A breast contusion, while painful, is generally a **minor injury** that typically resolves without long-term significant functional impairment or disfigurement. - It does not meet the criteria for a grievous injury under **IPC Section 320**, which requires severe, lasting physical harm or functional loss. *Multiple facial scars* - Multiple facial scars can lead to significant and **permanent disfigurement of the face**, which is explicitly listed as a grievous injury under IPC Section 320. - Such scarring can have profound psychological impacts and may require extensive reconstructive surgery. *Femur fracture* - A femur fracture is a **grievous injury** under IPC Section 320 as it constitutes a **"fracture or dislocation of a bone."** - Additionally, it results in **severe pain**, prolonged disability, and often requires extensive medical intervention including surgery, with potential for protracted loss of use of a limb. *Emasculation injury* - Emasculation refers to the **removal or destruction of male reproductive organs**, which is explicitly listed as a grievous injury under IPC Section 320. - This type of injury results in **permanent impairment of reproductive powers** and qualifies as privation of a member or joint.
Question 16: 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 17: In a case of hanging, the ligature marks on the neck are an example of which type of injury?
- A. Laceration
- B. Bruise
- C. Contusion
- D. Printed abrasion (Correct Answer)
Explanation: ***Printed abrasion*** - Ligature marks in hanging specifically refer to a type of **abrasion** where the pattern or texture of the ligature (rope, cord, etc.) is imprinted onto the skin. - This occurs due to the **pressure and friction** of the ligature against the epidermis, causing superficial scraping and leaving a distinct pattern. *Contusion* - A **contusion**, or bruise, results from bleeding into the tissues as a consequence of blunt trauma, causing discoloration of the skin. - While some mild bruising might coexist with ligature marks, the primary and distinctive injury from a ligature is an abrasion of the skin surface, not solely bleeding underneath. *Laceration* - A **laceration** is a tear or cut in the skin and underlying tissues typically caused by the forceful impact of a blunt object or shear forces. - Ligature marks from hanging are generally superficial skin injuries and do not involve deep tearing of tissues typical of a laceration. *Bruise* - A **bruise** is another term for a contusion, involving hemorrhage into the tissues without breaking the skin. - While bleeding may occur under the ligature mark, the defining characteristic of the mark itself is the superficial scraping or impression on the skin surface, which is an abrasion, not primarily a bruise.
Question 18: What is the effect of strychnos nux vomica poisoning on a patient's consciousness?
- A. Becomes unconscious within an hour
- B. Becomes unconscious only in severe cases
- C. Remains conscious throughout the poisoning (Correct Answer)
- D. Becomes unconscious immediately after exposure
Explanation: ***Remains conscious throughout the poisoning*** - Patients poisoned with **strychnine** (from *Strychnos nux vomica*) typically remain **fully conscious** and aware of their surroundings, even during severe convulsions. - This preservation of consciousness amidst intense muscular spasms is a **distinguishing and agonizing feature** of strychnine poisoning. *Becomes unconscious within an hour* - This statement is generally incorrect for strychnine poisoning, as the prominent feature is maintained consciousness alongside **neurological excitability**. - Loss of consciousness is not a **primary or direct effect** of strychnine, though severe complications could indirectly affect it. *Becomes unconscious only in severe cases* - While extreme metabolic derangements or secondary complications (e.g., severe hypoxia from prolonged seizures) might eventually lead to altered consciousness, the **direct pharmacological action** of strychnine does not cause unconsciousness. - The patient remains conscious even through the most severe and life-threatening **tetanic spasms**. *Becomes unconscious immediately after exposure* - Strychnine primarily acts as an **antagonist to glycine receptors** in the spinal cord and brainstem, leading to exaggerated reflexes and muscle overactivity, not immediate unconsciousness. - The onset of symptoms, including muscular spasms, typically occurs within **15-30 minutes** of exposure, with consciousness generally preserved.
Question 19: The odour of cyanide is similar to?
- A. Rotten egg
- B. Fish
- C. Fruity
- D. Bitter almond (Correct Answer)
Explanation: ***Bitter almond*** - The classic description of **cyanide odor** is that of **bitter almonds**. This specific scent is a key indicator during forensic investigations or in cases of suspected poisoning. - However, not everyone can detect this smell due to a **genetic trait** that affects the ability to perceive it. *Rotten egg* - A **rotten egg** odor is characteristic of **hydrogen sulfide (H2S)**, a highly toxic gas. - This gas is often produced by the decomposition of organic matter and does not indicate cyanide exposure. *Fish* - A **fishy odor** is typically associated with compounds like **amines**, such as **trimethylamine**, which are found in decomposing fish or certain medical conditions like **trimethylaminuria**. - This smell is distinct from the bitter almond scent of cyanide. *Fruity* - A **fruity odor** can be associated with various substances, including **ketones** in conditions like **diabetic ketoacidosis** or certain **volatile organic compounds**. - This scent is not characteristic of cyanide poisoning.
Question 20: Which of the following is true about cadaveric spasm?
- A. Occurs 2-3 h after death
- B. Some particular group of muscles are involved (Correct Answer)
- C. Involves involuntary muscles
- D. Disappears with rigor mortis
Explanation: ***Some particular group of muscles are involved*** - **Cadaveric spasm** is characteristically a **localized or partial phenomenon**, typically affecting specific muscle groups that were in intense contraction at the moment of death. - Classic examples include **hand gripping a weapon** (homicide/suicide), **clutching grass or mud** (drowning), or **specific limb muscles** during extreme physical exertion. - While generalized cadaveric spasm can theoretically occur, it is **usually partial and localized** to the muscles involved in the terminal activity. - This is a key distinguishing feature used in **medico-legal investigations** to determine circumstances of death. *Occurs 2-3 h after death* - This describes the typical onset of **rigor mortis**, which begins 2-3 hours post-mortem and follows a predictable progression. - **Cadaveric spasm** occurs **instantaneously at the moment of death** with **no flaccid interval**, unlike rigor mortis which has a pre-rigor flaccid phase. *Disappears with rigor mortis* - This is **incorrect**. Cadaveric spasm does **not disappear** when rigor mortis develops. - Instead, cadaveric spasm **persists and merges into rigor mortis**, becoming indistinguishable from it once rigor mortis is fully established. - Both cadaveric spasm and rigor mortis eventually resolve together during the **resolution phase** (24-36 hours post-mortem), not separately. *Involves involuntary muscles* - **Cadaveric spasm** affects only **voluntary (skeletal) muscles** under conscious control. - Involuntary muscles such as cardiac muscle and smooth muscles of internal organs are **not involved** in cadaveric spasm.