Injuries and Their Significance Practice Questions

Q: Myoglobinuria is usually seen in which type of burn?

Electric burn. **Explanation:** **Why Electric Burn is correct:** In high-voltage electrical injuries, the body acts as a conductor. As the current passes through tissues, the highest resistance is offered by bone, which generates significant thermal energy. This leads to deep-seated **coagulative necrosis** of the surrounding skeletal muscles (rhabdomyolysis). When muscle cells are damaged, they release **myoglobin** into the bloodstream. This myoglobin is filtered by the kidneys, leading to **myoglobinuria** (classically described as "port-wine" or "cola-colored" urine). This is a critical clinical finding as it can lead to Acute Tubular Necrosis (ATN) and subsequent renal failure. **Why the other options are incorrect:** * **Chemical Burn:** These primarily cause localized tissue damage via protein denaturation (acids) or liquefactive necrosis (alkalis). While systemic toxicity can occur depending on the chemical, massive muscle destruction leading to myoglobinuria is not a characteristic feature. * **Sun Burn:** This is a superficial (first-degree) burn caused by UV radiation. It involves only the epidermal layer and does not cause deep muscle injury. * **Closed Room Burn:** These are primarily associated with **inhalation injuries**, carbon monoxide (CO) poisoning, and cyanide poisoning due to smoke inhalation in a confined space. **High-Yield Clinical Pearls for NEET-PG:** * **The "Iceberg Effect":** In electrical burns, the external skin manifestation is often minimal (entry/exit wounds), but the internal tissue destruction is massive. * **Renal Protection:** The mainstay of treatment for myoglobinuria in burns is aggressive fluid resuscitation and **alkalization of urine** (using Sodium Bicarbonate) to prevent myoglobin precipitation in renal tubules. * **Most common cause of death** in immediate high-voltage shock is **Ventricular Fibrillation** (low voltage) or **Respiratory Paralysis** (high voltage).

Q: Bleeding from the external auditory meatus in a case of head injury is suggestive of which type of fracture?

Middle cranial fossa fracture. **Explanation:** Bleeding from the ear (otorrhagia) following head trauma is a classic clinical sign of a **Middle Cranial Fossa (MCF) fracture**. This occurs because the MCF contains the petrous portion of the temporal bone, which houses the middle and inner ear structures. When this bone fractures, it often results in a tear of the overlying dural membrane and the tympanic membrane, allowing blood (and sometimes CSF) to escape through the external auditory meatus. **Analysis of Options:** * **Middle Cranial Fossa (Correct):** The petrous temporal bone forms the floor of the MCF. Fractures here typically present with bleeding from the ear, CSF otorrhea, and potential injury to the VII (Facial) and VIII (Vestibulocochlear) cranial nerves. * **Anterior Cranial Fossa (Incorrect):** Fractures here typically involve the cribriform plate or orbital roof. Clinical signs include **"Raccoon eyes"** (periorbital ecchymosis), epistaxis, and **CSF rhinorrhea** (leakage through the nose). * **Posterior Cranial Fossa (Incorrect):** Fractures of the PCF or occipital bone present with **"Battle’s sign"** (post-auricular ecchymosis over the mastoid process), which usually appears 12–24 hours after the injury. * **Fracture of Occipital Bone (Incorrect):** While part of the PCF, an isolated occipital fracture does not involve the ear canal structures and would not cause bleeding from the ear. **NEET-PG High-Yield Pearls:** 1. **Battle’s Sign:** Bruising over the mastoid process (Posterior Cranial Fossa fracture). 2. **Raccoon Eyes:** Periorbital bruising (Anterior Cranial Fossa fracture). 3. **Halo Sign:** Used to detect CSF in blood; a clear ring forms around a central blood spot on a paper/linen. 4. **Target Sign:** Another name for the Halo sign, indicating a CSF leak. 5. **Panda Sign:** Another term for Raccoon eyes.

Q: Fish tailing of margins in a stab wound is seen with?

Single edged knife. ### Explanation **Concept:** A stab wound is a penetrating injury caused by a sharp-pointed instrument. The shape of the wound's margins (angles) is determined by the cross-section of the weapon used. **Why Single Edged Knife is Correct:** A **single-edged knife** has one sharp cutting edge and one blunt back (spine). When such a weapon enters the skin: 1. The sharp edge creates a **sharp, acute angle**. 2. The blunt back causes a **squared-off or "blunt" angle**. 3. As the weapon is withdrawn, the skin often stretches or shifts slightly. This movement, combined with the blunt back of the blade, creates a small split or secondary tear at the blunt end, resembling a **"fish-tail"** or a "Y" or "V" shape. **Why Other Options are Incorrect:** * **Double-edged knife:** Since both sides are sharp, both angles of the wound will be **sharp and acute**, resulting in a spindle or elliptical shape without fish-tailing. * **Bayonet:** These typically have a specific cross-section (like a "T" or "Y" shape) and produce a **tri-radiate or stellate** wound rather than a fish-tail. **High-Yield Clinical Pearls for NEET-PG:** * **Depth vs. Length:** In a stab wound, the **depth is the greatest dimension** (depth > length of the external wound). * **Rocking Action:** If the knife is "rocked" or twisted during entry/exit, the length of the external wound may be **greater** than the width of the blade. * **Langer’s Lines:** The shape of a stab wound (gaping vs. slit-like) depends on whether the wound is parallel or perpendicular to the skin's cleavage lines (Langer’s lines). * **Hilt Mark:** A bruise or abrasion surrounding the wound indicates that the weapon was thrust in to its full length (the handle/guard hit the skin).

Q: All are true about a gunshot entry wound except?

Entry wound is everted. ### Explanation In forensic ballistics, distinguishing between entry and exit wounds is critical. The correct answer is **C (Entry wound is everted)** because this is a characteristic feature of an **exit wound**, not an entry wound. #### Why the correct answer is right: * **Entry wounds** are typically **inverted** because the bullet pushes the skin inward as it penetrates. * **Exit wounds** are typically **everted** (turned outward) because the bullet, often deformed or tumbling, pushes the skin and subcutaneous tissues from the inside out. #### Analysis of other options: * **A. Entry wound is smaller than exit wound:** Generally true. As a bullet travels through the body, it loses stability, may fragment, or carry bone shards with it, creating a larger, more irregular exit. (Note: In contact shots over bone, entry wounds can be large/stellate, but as a general rule, exit wounds are larger). * **B. Entry wound is surrounded by a contusion collar:** True. As the bullet stretches the skin before piercing it, the edges are abraded and bruised, creating a "contusion/abrasion collar." This is absent in exit wounds. * **D. Entry wound is inverted:** True. This is a classic morphological feature of entry wounds due to the direction of force. #### High-Yield Clinical Pearls for NEET-PG: * **Abrasion Collar:** The most specific sign of an entry wound. * **Grease Ring (Dirt Collar):** Found only in entry wounds; caused by the bullet wiping off lubricant/lead/debris onto the skin. * **Contact Shots:** Look for **Cherry Red** discoloration of tissues (CO poisoning) and **Muzzle Imprints**. * **Tattooing (Peppering):** Caused by unburnt gunpowder grains; indicates an intermediate range shot. It cannot be washed off (unlike smudging/soot).

Q: An elderly person was found unconscious. The patient was deeply comatose with decerebrate and decorticate rigidity. MRI shows small hemorrhages on the corpus callosum and nothing else. The person dies after a week in coma. What is the most likely cause of death?

Diffuse axonal injury. ### Explanation **Diffuse Axonal Injury (DAI)** is the most likely diagnosis based on the clinical triad of immediate, prolonged coma, severe neurological posturing (decerebrate/decorticate), and characteristic imaging findings. **1. Why Diffuse Axonal Injury is Correct:** DAI occurs due to **rotational acceleration-deceleration forces**, leading to the shearing of axons. Clinically, there is an immediate loss of consciousness without a "lucid interval." A hallmark of DAI is the **discrepancy** between the severe clinical state (deep coma) and the relatively "normal" initial CT scan. MRI is more sensitive and typically shows micro-hemorrhages in high-stress areas: the **gray-white matter junction, corpus callosum (Grade II), and brainstem (Grade III).** **2. Why the Other Options are Incorrect:** * **Subdural Hematoma (SDH):** Usually caused by the tearing of bridging veins. Imaging would show a crescent-shaped, hyperdense collection crossing suture lines, not isolated corpus callosum lesions. * **Epidural Hematoma (EDH):** Associated with a skull fracture and middle meningeal artery tear. It presents with a "lucid interval" and a biconvex (lens-shaped) opacity on CT. * **Infarct:** Ischemic strokes present with focal neurological deficits corresponding to a specific vascular territory. While they can cause coma, they do not typically present with isolated punctate hemorrhages in the corpus callosum following trauma. **3. High-Yield Clinical Pearls for NEET-PG:** * **Most common site for DAI:** Gray-white matter junction (Frontal and Temporal lobes). * **Most specific site for DAI:** Corpus callosum (Splenium). * **Microscopic Hallmark:** **Axonal bulbs** or "retraction balls" (visible after 12–24 hours) due to the accumulation of axoplasm at the site of injury. * **Stain of choice:** Silver stains or Immunohistochemistry for **Beta-Amyloid Precursor Protein (β-APP)**.

Q: A full thickness wound having length greater than the depth, caused by a sharp object, is described as what?

Slash wound. **Explanation:** The correct answer is **Slash wound**. In forensic pathology, incised wounds are categorized based on the relationship between their surface length and their depth. 1. **Why it is correct:** A **Slash wound** is a type of incised wound where the **length is greater than the depth**. It is produced by a sharp-edged weapon (like a knife or sword) drawn across the skin. Because the force is applied tangentially, the injury is superficial relative to its length. 2. **Why the others are incorrect:** * **Stab wound:** This is a penetrating injury where the **depth is greater than the length** of the surface wound. It is caused by the thrust of a pointed object (e.g., a dagger) perpendicular to the body. * **Incision wound:** This is a general term for any wound caused by a sharp object. While a slash is a type of incised wound, "Slash" is the specific term used when length exceeds depth. * **Lacerated wound:** This is a blunt force injury caused by tearing or crushing of tissues. It is characterized by irregular, ragged edges and **tissue bridging**, which are absent in sharp force injuries. **High-Yield Clinical Pearls for NEET-PG:** * **Tailoring:** Incised wounds often show "tailoring"—the wound is deeper at the start (head) and shallower at the end (tail), helping determine the direction of the blow. * **Homicidal vs. Suicidal:** Slashes on the throat are often homicidal (cut-throat), while multiple superficial, parallel incised wounds on the wrist are characteristic **"Hesitation marks"** seen in suicide attempts. * **Weapon Width:** In a stab wound, the surface length of the wound roughly corresponds to the width of the blade, whereas in a slash wound, the length is independent of the blade's width.

Q: What is the characteristic appearance of a hard contact gunshot wound entry site?

Cruciate splitting. ***Cruciate splitting*** - **Hard contact gunshot wounds** create cruciate (star-shaped) or stellate splitting due to **muzzle gas expansion** beneath the skin surface. - The **high-pressure gases** from the firearm cause the skin to tear in a cross-like pattern around the entry wound. *Tattooing* - **Tattooing** (stippling) occurs in **intermediate range** gunshot wounds (2-3 feet), not hard contact wounds. - Results from **unburned gunpowder particles** embedding in the skin, creating a speckled appearance around the entry site. *Singeing of hair* - **Hair singeing** is characteristic of **near-contact** or **loose contact** wounds, not hard contact wounds. - Occurs when the **muzzle flame** burns hair fibers in the vicinity of the entry wound. *Abrasion collar* - **Abrasion collar** is present in **all gunshot entry wounds** regardless of firing distance, making it non-specific. - Represents the **rim of abraded skin** around the bullet hole but doesn't distinguish contact wounds from others.

Q: In an entry wound produced by a rifled gun, what phenomenon is observed?

Tattooing. ### Explanation The correct answer is **Tattooing**. In the context of a rifled firearm injury, tattooing (also known as stippling) is a hallmark feature of an **intermediate-range** entry wound. **1. Why Tattooing is Correct:** Tattooing is caused by the forceful impact of unburnt or semi-burnt gunpowder particles driven into the skin. Unlike soot, these particles are embedded deep into the dermis and cannot be washed off. This phenomenon occurs when the weapon is fired from a distance where the flame doesn't reach the skin, but the powder residue still possesses enough kinetic energy to penetrate (typically 30 cm to 1 meter for handguns). **2. Why Other Options are Incorrect:** * **Blackening (Sooting):** This is caused by the deposition of smoke. It is a surface phenomenon seen in **close-range** shots (up to 30 cm) and can be easily wiped away. * **Charring (Burning):** This results from the flame of the muzzle blast. It is seen in **contact or near-contact** shots (within a few centimeters). * **Grease Collar (Dirt Collar):** While this is seen in rifled firearm wounds, it is a feature of the **bullet itself** (wiping off lubricant/grime as it enters), not a phenomenon of the discharge products like tattooing. It is present regardless of the range. **3. High-Yield Clinical Pearls for NEET-PG:** * **Abrasion Collar:** A characteristic feature of all entry wounds (except those in palms/soles) caused by the friction of the spinning bullet. * **Muzzle Impression:** A cherry-red/pinkish indentation seen in **hard contact** shots due to carbon monoxide reacting with hemoglobin. * **Walker’s Test:** A chemical test used to detect nitrite residues (tattooing) on clothing. * **Distance Rule:** If tattooing is present but blackening is absent, the shot is likely from an intermediate range.

Question 1

Myoglobinuria is usually seen in which type of burn?

Accepted Answer

Electric burn

Answer

Chemical burn

Answer

Sun burn

Answer

Closed room burn

Question 2

Bleeding from the external auditory meatus in a case of head injury is suggestive of which type of fracture?

Accepted Answer

Middle cranial fossa fracture

Answer

Anterior cranial fossa fracture

Answer

Fracture of occipital bone

Answer

Posterior cranial fossa fracture

Question 3

A patient presents with a history of assault 2 hours prior, exhibiting multiple well-defined bruises with vesication over the flexor aspect of the left hand and the skin of the right leg. You suspect these bruises are artificially made. Which of the following findings would be most suggestive of an artificially made wound?

Accepted Answer

The wound margins are well-defined with small vesicles covering them

Answer

Bright red wound

Answer

Inflammation at the site of the wound

Answer

Extravasated blood present

Question 4

Fish tailing of margins in a stab wound is seen with?

Accepted Answer

Single edged knife

Answer

Double edged knife

Answer

Bayonet

Answer

None

Question 5

All are true about a gunshot entry wound except?

Accepted Answer

Entry wound is everted

Answer

Entry wound is smaller than exit wound

Answer

Entry wound is surrounded by a contusion collar

Answer

Entry wound is inverted

Question 6

An elderly person was found unconscious. The patient was deeply comatose with decerebrate and decorticate rigidity. MRI shows small hemorrhages on the corpus callosum and nothing else. The person dies after a week in coma. What is the most likely cause of death?

Accepted Answer

Diffuse axonal injury

Answer

Subdural hematoma

Answer

Epidural hematoma

Answer

Infarct

Question 7

What does a concussion cause?

Accepted Answer

Momentary interruption of brain function with or without loss of consciousness

Answer

Small hemorrhages and swelling of brain tissues

Answer

Tearing or shearing of brain structures

Answer

Bruising of the brain

Question 8

A full thickness wound having length greater than the depth, caused by a sharp object, is described as what?

Accepted Answer

Slash wound

Answer

Stab wound

Answer

Lacerated wound

Answer

Incision wound

Question 9

What is the characteristic appearance of a hard contact gunshot wound entry site?

Accepted Answer

Cruciate splitting

Answer

Tattooing

Answer

Singeing of hair

Answer

Abrasion collar

Question 10

In an entry wound produced by a rifled gun, what phenomenon is observed?

Accepted Answer

Tattooing

Answer

Blackening

Answer

Charring

Answer

Grease collar

Injuries and Their Significance — MCQs

Injuries and Their Significance — MCQs

On this page

Practice by Chapter

Want unlimited practice?