Penetrating Trauma: Velocity, Cavitation, Gunshot and Stab Wounds Practice Questions

25 multiple-choice questions on Penetrating trauma: velocity, cavitation, gunshot and stab wounds for paramedic and EMT students, from Chapter 30 (Trauma Systems and Mechanism of Injury). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. Penetrating trauma is classified by the energy of the object as low, medium, or high. Low-energy penetrating injuries are caused by:

   1. A. Handguns and most shotguns
   2. B. Hunting and assault rifles
   3. C. Shrapnel from high-order explosives
   4. D. Hand-driven objects such as knives
   Show answer

   Answer: D. Hand-driven objects such as knives

   Low-energy weapons damage only the tissue they directly contact along the path. Handguns and shotguns are medium energy.

2. Medium-velocity penetrating injuries are typically caused by:

   1. A. Knives and ice picks
   2. B. Handguns and shotguns
   3. C. Arrows shot from a bow
   4. D. High-powered hunting rifles
   Show answer

   Answer: B. Handguns and shotguns

   Handgun and shotgun projectiles create a temporary cavity several times their size. Hunting and military rifles are high velocity.

3. High-velocity weapons such as assault and hunting rifles cause more damage mainly because:

   1. A. Kinetic energy rises with velocity squared
   2. B. Their bullets are much heavier in mass
   3. C. They are usually fired from much closer range
   4. D. Their bullets are made of hardened steel
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   Answer: A. Kinetic energy rises with velocity squared

   Because KE depends on velocity squared, a fast rifle round carries far more energy than a heavier, slower handgun bullet. Bullet mass matters less than speed.

4. The temporary cavity in a gunshot wound is:

   1. A. The permanent track left behind by the bullet
   2. B. Gas trapped in tissue by the gunpowder
   3. C. The exit wound on the far side of the body
   4. D. Tissue briefly stretched away from the path
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   Answer: D. Tissue briefly stretched away from the path

   Pressure waves push tissue outward, then it rebounds, injuring vessels and organs far from the visible track. The permanent cavity is the track that remains.

5. Elastic tissue such as lung tolerates cavitation better than which tissue?

   1. A. Liver
   2. B. Skeletal muscle
   3. C. Skin
   4. D. Bowel wall
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   Answer: A. Liver

   Dense, inelastic solid organs such as the liver and spleen fracture when stretched, while lung and muscle stretch and rebound. Bowel is relatively elastic too.

6. Yaw refers to a bullet's:

   1. A. Forward spin imparted by the rifled barrel
   2. B. Wobble along its long axis in flight
   3. C. Breaking apart into many fragments
   4. D. Flattening into a mushroom shape
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   Answer: B. Wobble along its long axis in flight

   As a bullet yaws, a larger surface strikes the tissue, increasing energy transfer. Flattening is deformation or mushrooming.

7. Hollow-point bullets cause more damage because they:

   1. A. Travel faster than solid-point bullets
   2. B. Contain small explosive charges inside
   3. C. Expand on impact and increase surface area
   4. D. Pass straight through the body without deforming
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   Answer: C. Expand on impact and increase surface area

   Mushrooming increases drag and the profile of the bullet, so it dumps energy into tissue rather than exiting. They do not travel faster.

8. When a bullet tumbles in tissue, the result is:

   1. A. Less damage because the bullet slows down
   2. B. Greater energy transfer and tissue damage
   3. C. A smaller exit wound than entrance wound
   4. D. Damage limited to the skin surface
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   Answer: B. Greater energy transfer and tissue damage

   Tumbling presents more of the bullet's length to tissue, transferring more energy. Slowing in tissue is how energy is transferred, so it increases damage.

9. A patient was shot in the right upper quadrant. The exit wound is in the left lower back. You should assume the bullet:

   1. A. May have injured any organ along a possible path
   2. B. Traveled in a straight line between the two wounds
   3. C. Injured the liver and the right kidney
   4. D. Missed the major organs because it exited
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   Answer: A. May have injured any organ along a possible path

   Bullets deflect off bone and tissue, so the path between wounds is unpredictable. Exiting means less energy stayed in the body, not that organs were spared.

10. You are treating a man with two gunshot wounds to the torso, one small and one large. In your report you should:

    1. A. Label the larger of the two wounds as the entrance
    2. B. Label the smaller wound as the exit
    3. C. Describe the wounds without labeling them
    4. D. Leave both wounds out of the report
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    Answer: C. Describe the wounds without labeling them

    Wound size varies with range and bullet type, and mislabeling can mislead investigations. Exit wounds are often but not always larger, so describe location, size, and appearance instead.

11. A close-range gunshot wound may show:

    1. A. A smaller wound than one fired at long range
    2. B. No soot or residue on the skin
    3. C. Stippling found at the exit wound
    4. D. Powder burns or tattooing around the wound
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    Answer: D. Powder burns or tattooing around the wound

    Burning gunpowder deposits soot and tattooing near the entrance at close range, which matters for forensic investigation. Distant wounds lack these marks.

12. A 40-year-old man was shot in the abdomen with a shotgun from about 3 feet away. This wound is especially lethal because:

    1. A. The pellets strike together as one mass
    2. B. The pellets spread across a large area
    3. C. Shotguns are high-velocity weapons
    4. D. Shotgun shells hold more powder than rifles
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    Answer: A. The pellets strike together as one mass

    At close range the pellet mass acts like a single large projectile with massive tissue destruction. At distance the pellets spread and lose energy quickly.

13. A man was stabbed in the left chest, just below the nipple. The wound may have penetrated:

    1. A. The chest but not the abdomen
    2. B. The abdomen but not the chest
    3. C. The chest wall muscles, not a cavity
    4. D. Both the chest and the abdomen
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    Answer: D. Both the chest and the abdomen

    The diaphragm rises to about the fourth intercostal space on expiration, so a wound below the nipple may enter both the chest and the abdomen. Assuming the chest but not the abdomen misses spleen or stomach injury. Assuming the abdomen but not the chest misses a pneumothorax or hemothorax. Assuming only the chest wall muscles are injured underestimates a stab wound whose depth cannot be judged in the field.

14. A 26-year-old man was stabbed once in the left flank. The skin wound is 2 cm long and external bleeding is minimal. Which information best helps you anticipate how deep the wound may go?

    1. A. The length of the skin wound
    2. B. The amount of external bleeding
    3. C. The length of the blade used
    4. D. The patient's pain rating
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    Answer: C. The length of the blade used

    Depth depends on blade length plus the force and angle of the thrust, and because the abdominal and flank walls compress, the wound can even be deeper than the blade. The skin wound length reflects the blade width and angle, not depth. Minimal external bleeding does not exclude internal or retroperitoneal hemorrhage from the kidney, spleen, or bowel. Pain is subjective and is blunted by adrenaline and intoxication. Whatever the answer, a flank wound is torso penetration, a red criterion in the national field triage guideline. Older generalizations about the attacker's sex and stab direction are not evidence-based and should not guide care.

15. Knife wounds may be more serious than they appear because:

    1. A. Knives cause cavitation larger than bullets
    2. B. The blade may have been moved inside the wound
    3. C. Knife wounds usually involve major vessels
    4. D. The skin wound overstates the internal damage done
    Show answer

    Answer: B. The blade may have been moved inside the wound

    An attacker may twist or move the knife, creating more internal damage than the skin wound suggests. Knives are low energy and do not cause significant cavitation.

16. A 24-year-old has a screwdriver impaled in his thigh. Bleeding is controlled. You should:

    1. A. Stabilize it in place with bulky dressings
    2. B. Pull it out to control the bleeding better
    3. C. Cut it flush with the skin surface
    4. D. Twist it to see how deep it goes
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    Answer: A. Stabilize it in place with bulky dressings

    Removing an impaled object can release a tamponade and cause severe bleeding. It may be removed only if it is in the cheek and blocks the airway or interferes with CPR.

17. An impaled object may be removed in the field when it:

    1. A. Is in the chest with mild bleeding
    2. B. Is longer than the paramedic's forearm
    3. C. Causes the patient severe pain
    4. D. Obstructs the airway through the cheek
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    Answer: D. Obstructs the airway through the cheek

    A cheek impalement can obstruct the airway and can be stabilized from both sides once removed. Pain is treated with analgesia, not removal.

18. A 19-year-old was shot once in the abdomen with a handgun. He is pale, P 128/min, BP 88/50 mmHg. Your priority is to:

    1. A. Start two large-bore IVs on scene
    2. B. Limit scene time and transport rapidly
    3. C. Give a 2-liter fluid bolus before moving him
    4. D. Wait on scene for air medical
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    Answer: B. Limit scene time and transport rapidly

    He needs a surgeon to stop internal bleeding, so scene time should be 10 minutes or less, with permissive hypotension and fluids titrated en route. A 2-liter bolus raises pressure and dilutes clotting factors. IV access can be gained en route, and waiting on scene for a helicopter delays surgery when ground transport is available.

19. Police are on scene after a shooting, and you need to expose a 22-year-old patient's chest. When cutting his clothing you should:

    1. A. Cut through the holes to see wounds faster
    2. B. Discard the clothing at the scene
    3. C. Avoid cutting through bullet or knife holes
    4. D. Shake out the clothing to remove debris and glass
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    Answer: C. Avoid cutting through bullet or knife holes

    Holes in clothing are evidence of range and direction. Bag clothing per protocol and hand it to law enforcement, preserving the chain of custody.

20. Which gunshot wound location is the most immediately life-threatening?

    1. A. Upper arm
    2. B. Lateral thigh
    3. C. Anterior neck
    4. D. Foot
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    Answer: C. Anterior neck

    The neck holds the airway, major vessels, and spinal cord, all of which can be fatal within minutes. Extremity wounds can be dangerous but are often controlled with a tourniquet.

21. Under the 2021 field triage guideline, a penetrating injury to which area is a red criterion?

    1. A. Hand or foot with bleeding controlled by pressure
    2. B. Distal forearm with a small wound
    3. C. Lower leg below the knee
    4. D. Head, neck, torso, or proximal extremity
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    Answer: D. Head, neck, torso, or proximal extremity

    Penetrating wounds to these areas can injure vital organs and major vessels and go to the highest-level center. Distal extremity wounds are not red criteria unless bleeding needs a tourniquet.

22. The drag on a projectile refers to:

    1. A. Factors that slow it during flight
    2. B. The spin it gets from the barrel
    3. C. The amount of powder in the cartridge
    4. D. The size of the wound it leaves
    Show answer

    Answer: A. Factors that slow it during flight

    Air resistance slows a projectile, so range affects the energy left at impact. Spin from barrel rifling stabilizes flight.

23. A bullet that strikes bone can cause additional injury because:

    1. A. Bone absorbs all of the bullet's kinetic energy
    2. B. Bone fragments become secondary missiles
    3. C. The bullet usually stops in the bone
    4. D. Bone shields the organs beneath it
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    Answer: B. Bone fragments become secondary missiles

    Shattered bone fragments travel into surrounding tissue and the bullet may change course. Bone does not absorb all the energy.

24. A woman has a small stab wound to the right upper abdomen. She is alert, BP 122/78 mmHg, P 96/min. The best approach is to:

    1. A. Clean and bandage it and advise follow-up care
    2. B. Release her because the wound is small
    3. C. Probe the wound to estimate its depth
    4. D. Treat it as serious and go to a trauma center
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    Answer: D. Treat it as serious and go to a trauma center

    Small external wounds can hide liver or vessel injury, and torso penetration is a red criterion. Probing a wound can worsen injury and is never done in the field.

25. A hunter was hit by an arrow that is still in his upper arm. Compared with a gunshot wound, the arrow injury is:

    1. A. Larger because of a temporary cavity
    2. B. Limited to tissue along its direct path
    3. C. Larger because of tumbling in tissue
    4. D. Spread widely because the arrow fragments
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    Answer: B. Limited to tissue along its direct path

    Arrows are low-energy projectiles that injure by cutting, with little cavitation. They should be stabilized in place like any impaled object.