Legal Medicine: Decomposition of Human Remains PDF

**OUTLINE** I. **Introduction** II. **Decomposition** III. **Fate of the Body after Death** A. Putrefaction B. Adipocere Formation C. Mummification D. Animal Predation IV. **Estimation of Postmortem Interval** A. Postmortem Cooling B. Rigor Mortis C. Forensic Entomology D. Other...

**OUTLINE** I. **Introduction** II. **Decomposition** III. **Fate of the Body after Death** A. Putrefaction B. Adipocere Formation C. Mummification D. Animal Predation IV. **Estimation of Postmortem Interval** A. Postmortem Cooling B. Rigor Mortis C. Forensic Entomology D. Other Methods of PMI Estimation V. **Approach to Estimating PMI** +-----------------------+-----------------------+-----------------------+ | **LEGEND** | | | +=======================+=======================+=======================+ | ⭐ | 🖊️ | 📖 | | | | | | Must | Lecture | Book | | | | | | Know | *\[lec\]* | *\[bk\]* | +-----------------------+-----------------------+-----------------------+ I.INTRODUCTION {#i.introduction.TransOutline} ============== - **"Death is a process not an event"** - 🖊️ *When we certify death, we have to **write the time of death**. So, we have to pinpoint a particular time wherein we say that the patient or the person has died, but in reality, from the pathological perspective, that is actually a process. Some parts of the body might have already died while some parts are still alive. We'll be talking about the process of dying, the various parts, organs, and tissues of the body dying, and how that would look like.* II. DECOMPOSITION {#ii.-decomposition.TransOutline} ================= - **"The rate differs from body to body, environment to environment, sometimes even one part of the same corpse to another"** - 🖊️ *One part of the body might be decomposing faster than another part of the body, or between two bodies buried in the same cemetery.* - *🖊️ It's not all the time that an entire body is subjected to exactly the same sort of environment. There might be mini environments to which different parts of our bodies are exposed, which would account for the varying rates of decomposition.* A. INTERNAL {#a.-internal.TransSubtopic1} ----------- - **Cellular autolysis** - Occur due to the action of digestive enzymes - **Tissue autolysis** - Occur due to the action of intracellular enzymes - 🖊️ *During decomposition, these occur at the very moment of the irreversible cessation of cardiac, respiratory, or brain functions.* B. EXTERNAL {#b.-external.TransSubtopic1} ----------- - **Putrefaction** - 🖊️ *The microorganisms responsible for putrefaction come from within one's gut, mainly the intestines.* - *🖊️ It's still considered an external process because even though these microorganisms are in our gut, they are not part of our body.* - **Animal predation** - 🖊️ *Can refer to anywhere between small animals like maggots to dogs and such.* III.FATE OF THE BODY AFTER DEATH {#iii.fate-of-the-body-after-death.TransOutline} ================================ **Figure 1.** The fate of the body after death - 🖊️ [Most common process:] - After death, most of the time people undergo **moist putrefaction** → leading to **skeletonization** → and over many years, humans become **completely dissolved** and one with nature. - 🖊️ [Alternative] to moist putrefaction: - **Mummification (dry decomposition)** - **Adipocere formation** - Both can occur at the same time in the same corpse because different parts of the body may be exposed to different mini environments even in the same coffin. - If adipocere formation occurs, that does not necessarily exclude moist putrefaction or mummification altogether and vice versa. - Ultimately, if the corpse undergoes moist putrefaction, mummification, adipocere formation, or a mix of all these, the final stage of decomposition would be skeletonization before complete dissolution. - 🖊️ **Animal predation** - *Assists in the skeletonization process regardless of the initial decomposition process.* A. PUTREFACTION {#a.-putrefaction.TransSubtopic1} --------------- - The usual process of corruption of the dead body - **Timescale is highly variable** due to a wide range of factors that affect its rate - Generally, rate: **Air\> Water\> Earth** +-----------------------------------+-----------------------------------+ | **Table 1. Difference between | | | Accelerate and Slow** | | +===================================+===================================+ | **Accelerate** | **Slow** | +-----------------------------------+-----------------------------------+ | - Animal predation | - Cold and dry environment | | | | | - 🖊️ *Take huge chunks of | - 🖊️ *In fact, in freezing | | flesh, allowing more | environments, it might be | | microorganisms to come in | postponed indefinitely* | | and hasten the | | | putrefactive process* | - Tight clothing/supporting | | | surface | | - Hot and moderately humid | | | environment | - Infants | | | | | - Body exposed to air after | - Thin individuals | | water immersion | | | | - Body immersed in water, under | | - 🖊️*Body immersed in water | soil | | putrefies slower than in | | | air, but the moment it's | - Coffins | | taken out of the water, | | | it would putrefy much | - Embalming | | faster than the body that | | | was just originally | | | exposed to air* | | | | | | - Body thawed/rewarmed after | | | previous freezing | | | | | | - Heavy clothing | | | | | | - Sepsis | | | | | | - 🖊️*Particularly those who | | | died with **Clostridium | | | infections*** | | | | | | - Fever at time of death | | | | | | - Obese | | | | | | - Diabetic | | +-----------------------------------+-----------------------------------+ {#section.TransSub-subtopic2} SEQUENCE OF THE PUTREFACTIVE CHANGES {#sequence-of-the-putrefactive-changes.TransSub-subtopic2} ------------------------------------ - 🖊️ *Regardless of the highly variable rate of putrefaction, there's a general consensus about the sequence of putrefactive changes.* - *🖊️ This chronology of putrefactive change is typically seen regardless of the overall rate of putrefaction.* #### EXTERNAL CHANGES {#external-changes.TransSub-subtopic3} **1. Reddish-green discoloration** - 🖊️ *First sign of putrefactive changes* - *🖊️ Normally first visible in the RLQ of the abdomen* - Since the microorganisms responsible for putrefaction come from the gut, and the most superficial over that area is the **cecum** - Occurs due to hemolysis (breakdown of hemoglobin) due to the actions of these putrefactive microorganisms - This discoloration would start spreading initially throughout the abdomen **2. Reddening and swelling of face and neck** - 🖊️*The by-products of the actions of the microorganisms would include putrefactive gases. One of the first parts of the body where you would appreciate this would be the face and neck* **3. Marbling** - 🖊️*Arborescent patterns/ staining that follows the blood vessels because of the hemolysis within them*  **Figure 2.** Marbling **4. Skin blistering/ slippage** - 🖊️ *Putrefactive fluids would seep into epidermal layers → vesicle formation → would eventually become so large and start to fall off (over the scalp, hair would start falling off because of this)* **5. Marked gas formation and purging of decompositional fluid** - 🖊️ *Because of more by-products and more gases due to the actions of the microorganisms* - Bloated and very tense body, bloated face, bloated genitalia - Due to increasing abdominal pressure → purging of feces, urine - 🖊️Don't confuse this with antemortem incontinence - If the uterus was gravid, there might be postmortem expulsion of the fetus - Eyeballs, tongue might be protruding out - Purging of frothy, hemorrhagic-looking fluid through the nostrils and mouth - 🖊️*These are not actually blood, but just putrefactive fluids mixed with hemolyzed blood* - *🖊️Don't confuse with trauma or lethal hemorrhaging* A close-up of a person\'s knee Description automatically generated  **Figure 3**. Bloated/ swollen genitalia (top) Purging (bottom) **6. Dark green to blackish discoloration** - 🖊️*Due to the continuous breakdown of hemoglobin* **7. Heavy maggot infestation** **8. Fingernails and toenails loosen and fall** #### INTERNAL CHANGES {#internal-changes.TransSub-subtopic3} - Proceeds more slowly than at the surface - Organs putrefy at markedly different rates - 🖊️*Softer organs putrefy first* - [EARLY]: Liver, spleen, pancreas, brain, gravid uterus - [LATER]: Firmer or muscular organs and tissues (i.e. heart, esophagus, non-gravid uterus, diaphragm, prostate, urinary bladder, lungs, kidneys) - Organs will ultimately liquefy - 🖊️*starts to soften, be clay-like in texture, and liquefy* - **BRAIN** - Even though it's beginning to putrefy, meningeal hemorrhages and hematoma persist rather well - Non-hemorrhagic lesions vanish quite early - 🖊️*So, if it might be an important COD, it might not be appreciated anymore in a body that is in a rather advanced state of decomposition* - **HEART** - 🖊️ *Moderately resistant to decomposition (doesn't decay early, but isn't the last as well)* - Examination of coronary arteries for the degree of atheromatous stenosis may be well worthwhile for many months - 🖊️*May show **"Miliary Plaques"*** - A white granularity on the epicardial and endocardial surfaces, seen either during putrefaction or even on exhumation after a long interval - Appears to be a degenerative product of the cardiac tissue - It seems to be particular to the heart, but nothing of clinical importance, just an artifact of decomposition - **BODY FAT** - Liquefy into a translucent, yellow fluid that fills the body cavities - 🖊️ *Especially when dealing with obese corpses* - **ESOPHAGUS & STOMACH** - **Esophagomalacia and Gastromalacia** - Autodigestion of the lower esophagus and stomach - Mucosa turns grayish-white to black in appearance and is extremely friable - To such a degree that it eats through the entire wall of the esophagus or stomach - Just an artifact of decomposition and means absolutely nothing clinically or nothing related to the decedent's cause of death - May cause rupture - No inflammation microscopically - Can tell you that there are no ulcerations that occurred during the life - No reddening, no inflammation, no infiltration of inflammatory cells - Occurs either immediately prior to or after death - Has no clinical significance B. ADIPOCERE FORMATION {#b.-adipocere-formation.TransSubtopic1} ---------------------- - **Adipocere** from the lat. **Adeps** = fat, and **Cera** = wax - A greasy or waxy substance that overtime becomes brittle and chalky - Color can vary from **off white**, to pinkish, to grey or greenish-grey - 🖊️ Depending on what may have stained it, but adipocere itself is colored off white - Smells earthy, cheesy, and ammoniacal - Caused by **hydrolysis and hydrogenation** of adipose tissue - In most instances, formation is partial and irregular - Occasionally almost the whole body may be affected - 🖊️May only be seen in some parts of the body like the buttocks and cheeks - Quite common in buried or concealed corpses in only small amounts - **Requires some moisture, and some warmth** which is required by anaerobes (e.g. [Clostridium perfringens]) - Typical seen in immersed bodies and those in wet graves and damp vaults - Mainly affects the subcutaneous fat, but it may also preserve practically fat anywhere - 🖊️i*.e., Perirenal fatty deposits, omentum, mesentery, or in organs that are pathologically fatty (like those who died with fatty liver)* - **Inhibits putrefaction** - 🖊️ *[Forensic significance]: allows the preservation of major anatomical features in soft tissue injuries or the possibility of facial recognition even after so many years* - [Time required to form: **3-12 months**] (but has been seen in as early as 3 weeks) - Firm cast of fatty tissue that may persist for decades/centuries - May preserve major anatomical features and injuries A large raw chicken on a metal tray Description automatically generated **Figure 4.** Adipocere formation C. MUMMIFICATION {#c.-mummification.TransSubtopic1} ---------------- - A drying of the tissues in place of liquefying putrefaction - **Requires a dry environment**, preferably with a moving air current, and is usually warm - The most widely known forms of mummification are those in hot, desert zones - Most common ones are in **closed rooms/concealed spaces** - 🖊️*Those left undisturbed, like under floorboards* - Tends to be seen in **fetuses or newborn infants** - 🖊️*Due to their peculiar low mass-to-surface area ratio → makes evaporation and desiccation easier* - Looks like a **desiccated corpse** - Brittle skin - Skin is stretched tightly across anatomical prominences such as the cheekbones, chin, costal margins, and hips - Skin is discolored (appear leathery and brown) - Skin and underlying tissues are hard - May preserve major anatomical features and injuries - Facial recognition may be possible and soft tissue injuries may still be visible - The timescale is not well documented but takes some weeks  **Figure 5.** Mummified/ desiccated corpse D. ANIMAL PREDATION {#d.-animal-predation.TransSubtopic1} ------------------- - 🖊️*Hastens rate of decomposition to such a point that it is reduced to a skeleton* - Varies greatly with geography, season, and whether the dead body is indoors or out in the open - Varies in appearance according to the size and shape of the teeth or jaws of the predator but bears characteristic postmortem features 1. CANINE {#canine.TransSub-subtopic2} --------- - Local, **irregular tearing** of large amounts of flesh - Usually accompanied by evidence of teeth marks - May leave punctured wounds adjacent to the damaged edge where sharp teeth have penetrated 2. RODENTS AND CATS {#rodents-and-cats.TransSub-subtopic2} ------------------- - Leave a crenated edge to **fairly clean-cut wounds** 3. MAGGOTS {#maggots.TransSub-subtopic2} ---------- - **Most active tissue removers** - The larval stage of flies - The adult insects lay eggs on the fresh corpse (or on a debilitated live victim) choosing moist areas first (e.g., mouth, eyelids, lips, nostrils, and genitalia) or wounds then anywhere once skin decomposition begins - 🖊️ *One way by which you can identify antemortem injuries is because, in a fresh corpse, you expect them to go to the face since it's where the moist areas are* - If they are depositing their eggs in other parts of the body while the corpse is still fresh, that is indicative of an antemortem injury - They **secrete proteolytic enzymes** that allow them to burrow beneath the skin, making tunnels and sinuses that hasten putrefaction - They first go through the natural orifices (mouth, GIT) but when decomposition starts breaking down the barriers of the skin, they can start making tunnels and sinuses → more air coming into the body, more venues for microorganisms to hasten putrefaction - Eventually, loss of tissue and drying make the host cadaver unattractive to egg-laying 4. ANTS {#ants.TransSub-subtopic2} ------- - Often attack the body even **before putrefaction begins** - Common place of attack: eyelids, lips, and on the knuckles - Leave **superficial ulcers with scalloped, serpiginous margins** - Can be mistaken for antemortem abrasions - 🖊️*Differentiate from postmortem changes or injuries by looking for signs of inflammation* 5. OTHERS {#others.TransSub-subtopic2} --------- - Fish, Crustaceans - Birds - 🖊️*Like to pick out the eyes and tissues from the neck* IV.ESTIMATION OF POSTMORTEM INTERVAL {#iv.estimation-of-postmortem-interval.TransOutline} ==================================== - Postmortem cooling or "Algor Mortis" - Rigor mortis - Forensic entomology "None of the methods used in establishing PMI are totally reliable and mathematically precise. Dogmatic and pinpoint accuracy...is not achievable. \[But taking all these methods and environmental and individual influences into consideration\] frequently permit determination of a realistic range of PMI." A. POSTMORTEM COOLING {#a.-postmortem-cooling.TransSubtopic1} --------------------- - 🖊️*Happens as a result of the natural tendency to achieve equilibrium between two objects in space* - *🖊️When we die, normally we're hotter than the environment, that's why we cool down* - Except where the environmental (ambient) temperature remains at or even above 37º C, the human body will cool after death - **[Theory]**: PMI can be extrapolated based on the decrease in core body temperature following death - **Plateau**: you don't immediately cool down, for an indefinite period of time; then - There's an **exponential drop** following the Newtonian principle - Then **another plateau** as we reach equilibrium with the ambient temperature - 🖊️ *If we have a temperature reading from the time the body was discovered, then we can extrapolate based on the graph the time interval between the time of discovery and the time of death -- but it is highly variable, cannot be used as an accurate measure of PMI, have to use it with the other methods* - 🖊️***None of the methods are accurate by themselves**, and even together they cannot be considered as totally accurate -- but at least together can be used to get a realistic range of PMI* A diagram of a physical reaction Description automatically generated with medium confidence **Figure 6.** Theory of Post-mortem Cooling/ Algor mortis FACTORS THAT AFFECT THE PHENOMENON {#factors-that-affect-the-phenomenon.TransSub-subtopic2} ---------------------------------- - **Ambient temperature** - 🖊️*Most important factor* - *🖊️If it is very cold, then you expect that cooling will occur a lot faster* - **Air movement and humidity** - 🖊️*Post-mortem cooling is accelerated when there is an active air current* - **Medium around the body** - 🖊️*If immersed in water, especially flowing water, it hastens the process* - **Body mass** - 🖊️*Smaller body masses and those who are relatively thin tend to cool faster* - **Body fat** - 🖊️*High body fat tends to retard post-mortem cooling since it serves as insulation* - **Clothing** - 🖊️*Retards since it serves as insulation* - **Surface area exposed** - 🖊️*Infants and small children have higher surface areas and tend to cool faster* - 🖊️*A person can cool faster if they die in a supine position versus in a fetal position* - **Diurnal variations** - 🖊️*In core body temperature* - **Significant physical activity at the time of death** - 🖊️*Increases body temperature and alters post-mortem cooling* - **Different temperatures in different parts of the body** - 🖊️*Even antemortem, you would see variations between rectal, axillary, and oral temperatures* - **Dehydration** - 🖊️*A person who is dehydrated tends to cool faster* - **Edema** - 🖊️*Slowed down because of the capacity of fluids to retain heat* - **Fever at the time of death** - **Drug reactions** - 🖊️*Cocaine overdose can decrease core body temperature* HENSSGE'S NOMOGRAM METHOD {#henssges-nomogram-method.TransSub-subtopic2} ------------------------- - One of the most useful practical guides - Adjusted for: - Body weight - Ambient temperature - Dry or wet clothing - Still or moving air - Still or flowing water - Results in given with different ranges of error, with a **95% probability, ± 2.8 -- 7 hours** - [Limitation]: Does not allow for variation of these factors over time B. RIGOR MORTIS {#b.-rigor-mortis.TransSubtopic1} --------------- - Immediately after death, there is general muscular **flaccidity (3-6 hours),** followed by a period of **rigidity (full 12 hours to 24 hours),** which in turn passes off as the signs of decomposition appear - 🖊️ *Body is fully rigid, including smooth muscles, and expected to be complete upon 12 hours from death and persist after 24 hours* - *🖊️ After that, muscles undergo a stage of secondary flaccidity, that's when the rigor mortis starts to pass off due to the decay because of putrefaction* - [Theory]: PMI can be estimated based on the timing of the phenomenon FACTORS THAT AFFECT THE PHENOMENON {#factors-that-affect-the-phenomenon-1.TransSub-subtopic2} ---------------------------------- - **Temperature of environment** - 🖊️*Cold temperature -- slower rigor mortis* - *🖊️Freezing -- rigor mortis may be postponed indefinitely* - **Physical activity shortly before death** - **Electrocution** - 🖊️*Faster rigor mortis* - **Muscle mass** - 🖊️*Smaller -- faster rigor mortis* - **Drugs** - 🖊️*Certain drugs hasten this phenomenon (i.e. Strychnine)* C. FORENSIC ENTOMOLOGY {#c.-forensic-entomology.TransSubtopic1} ---------------------- - 🖊️*This is no longer forensic pathology but it's important to note that these exist and are relied upon by forensic professionals.* - *🖊️It's a different branch of forensic science altogether but they are also important to consider in estimating PMI* - **Rationale:** Invasion of an unprotected body by **sarcosaprophagous insects** and other small fauna comes in successive waves - 🖊️ *These are known facts because they don't just come in all at the same time. Typically, flies come first before beetles and other types of arthropods.* - *🖊️ Entomologists know the succession; they know which insects or arthropods would visit the body first and they also understand the life cycles of such.* - *🖊️It is by no means an exact science, just like the estimation of the PMI by post-mortem cooling and rigor mortis, but these three taken together can give a good estimate of the PMI.* - Different species of arthropods colonize the corpse at different periods after death - Some species pass through complex life cycles that can be used to determine at least the minimum time since death by studying the stage of the life cycle of the insects - 🖊️*Based on the stage of life that they see, and the different arthropods that they see, they can make a good estimate of the PMI* D. OTHER METHODS OF PMI ESTIMATION {#d.-other-methods-of-pmi-estimation.TransSubtopic1} ---------------------------------- - 🖊️*Not really useful for practical purposes but we still study them for academic purposes* - **Stomach emptying** - [Theory]: PMI can be estimated from the amount of food left in the stomach if the time of the last meal was known on the hypothesis that gastric emptying time is known - 🖊️*In reality, we don't really know the gastric emptying time because there are so many factors that come into play that could affect its rate* - *🖊️Can be affected by the emotional state of the deceased at the time of death; we know this to affect the gastric motility* - *🖊️Even the type of food eaten may affect gastric emptying time. **Fatty food** tends to retard the rate of gastric emptying but just by how much, we can't really say, such that the degree of mastication of the person if it's fast or slow, or if the food bolus is rather big that could retard the gastric emptying time, we can't say.* - *🖊️**No longer used anymore*** - **Vitreous humor potassium** - 🖊️ *Ultimately found to be **unreliable and no longer used** but do note that potassium, as an established fact, its concentration in the vitreous humor rises after death.* - [Theory]: PMI can be calculated from the rise of potassium in the vitreous humor following death - 🖊️*The problem is, it's also very variable. The potassium concentration towards the back of the eyeball is generally higher than the potassium concentration towards the front of the eyeball. There's even a variety of potassium concentrations between the left and the right eye.* - *🖊️Researches have shown an error of margin of as little as 1 hour to as much as 26 hours from the true PMI* V.APPROACH TO ESTIMATING PMI {#v.approach-to-estimating-pmi.TransOutline} ============================ **1. Establish a wide window of death** (time interval prior to which one may assert with confidence that the individual was alive) -- established by scene markers: - Testimony of a witness who last saw a person alive - 🖊️*This is very unscientific but also probably the most reliable. If you saw the person alive, then he couldn't have died earlier than that point in time. So, that's one way to establish a wide window of death.* - Last time of withdrawal from bank accounts, etc. - Cell phone calls or text messages - Uncollected parcels - How the individual is dressed - Any food that is out or dirty dishes in the sink - Sales receipts or dated slips of paper in the deceased's pockets **2. Narrowing the window of death by clocking postmortem changes** - 🖊️*Basically, if there's a cold body already, as a rule, that tells you that the corpse has probably been dead for at least 24 hours* - 🖊️*If the corpse is warm and flaccid, then probably less than 3-6 hours of death* - *🖊️If the body is rather warm but in various stages of muscular rigidity, then you try to clock that using the rigor mortis phenomenon* **3. Algebraic integration of the timing of postmortem changes into a range of PMI** 🖊️ ***Note:** There's no way we can dogmatically pinpoint the exact time of death. We have to take into consideration all the factors that we know.* GUIDE QUESTIONS {#guide-questions.TransOutline} =============== 1. What are the artifacts of decomposition or the anatomical changes in the body that occur after death? - **DECOMPOSITION** - **Internal** - **Cellular autolysis** - **Tissue autolysis** - **External** - **Putrefaction** - External Changes 1. Reddish-green discoloration 2. Reddening and swelling of face and neck 3. Marbling 4. Skin blistering/ slippage 5. Marked gas formation and purging of decompositional fluid 6. Dark green to blackish discoloration 7. Heavy maggot infestation 8. Fingernails and toenails loosen and fall - Internal Changes - [EARLY]: Liver, spleen, pancreas, brain, gravid uterus - [LATER]: Firmer or muscular organs and tissues (i.e. heart, - **Animal predation** - **Alternative** - **Mummification (dry decomposition)** - **Adipocere formation** 2. How is postmortem interval or \"time since death\" estimated from the artifacts of decomposition? - Postmortem cooling or "Algor Mortis" - **[Theory]**: PMI can be extrapolated based on the decrease in core body temperature following death a. **Plateau**: you don't immediately cool down, for an indefinite period of time; then b. There's an **exponential drop** following the Newtonian principle c. Then **another plateau** as we reach equilibrium with the ambient temperature - Rigor mortis - Immediately after death, there is general muscular **flaccidity (3-6 hours),** followed by a period of **rigidity (full 12 hours to 24 hours),** which in turn passes off as the signs of decomposition appear - [Theory]: PMI can be estimated based on the timing of the phenomenon - Forensic entomology - **Rationale:** Invasion of an unprotected body by **sarcosaprophagous insects** and other small fauna comes in successive waves 3. What fields of forensic science other than forensic medicine have been used to estimate postmortem interval? - **Stomach emptying** - [Theory]: PMI can be estimated from the amount of food left in the stomach if the time of the last meal was known on the hypothesis that gastric emptying time is known - **Vitreous humor potassium** - [Theory]: PMI can be calculated from the rise of potassium in the vitreous humor following death REVIEW QUESTIONS / QUIZ \#2 {#review-questions-quiz-2.TransOutline} =========================== 1. Thin corpses tend to cool and putrefy faster a. True b. False +-----------------------------------------------------------------------+ | **RATIONALE** | | | | ANSWER: B | | | | - **Thin corpses tend to cool faster** | | | | - 🖊️*Smaller body masses and those who are relatively thin tend | | to cool faster* | | | | - **Thin corpses tend to putrefy slower** | +-----------------------------------------------------------------------+ 2. The structure of the frontal sinus is as unique as his teeth c. True d. False +-----------------------------------------------------------------------+ | **RATIONALE** | | | | ANSWER: A | | | | - **Frontal sinus** | | | | - Most unique among skull sinuses, **no two individuals have | | the same frontal sinus** even if you have a twin: as good as | | the fingerprint or dental analysis | | | | - Well-protected  | | | | - Only fully develops by early adulthood  | +-----------------------------------------------------------------------+ 3. The usual process of decomposition involves moist putrefaction e. True f. False +-----------------------------------------------------------------------+ | **RATIONALE** | | | | ANSWER: A | | | | - [Most common process:] | | | | - After death, most of the time people undergo **moist | | putrefaction** → leading to **skeletonization** → and over | | many years, humans become **completely dissolved** and one | | with nature. | +-----------------------------------------------------------------------+ 4. Gross examination findings in autopsy may only yield, at best, a presumptive identification g. True h. False +-----------------------------------------------------------------------+ | **RATIONALE** | | | | ANSWER: A | | | | - Gross examination; Presumptive identification or possibly just a | | speculative one; unlikely to get definitive ones. | +-----------------------------------------------------------------------+ 5. The most active postmortem tissue removers among the animal predators are canines i. True j. False +-----------------------------------------------------------------------+ | **RATIONALE** | | | | ANSWER: B | | | | - **Maggots are the most active tissue removers** | | | | - The larval stage of flies | | | | - The adult insects lay eggs on the fresh corpse (or on a | | debilitated live victim) choosing moist areas first (e.g., mouth, | | eyelids, lips, nostrils, and genitalia) or wounds then anywhere | | once skin decomposition begins | | | | - 🖊️ *One way by which you can identify antemortem injuries is | | because, in a fresh corpse, you expect them to go to the face | | since it's where the moist areas are* | +-----------------------------------------------------------------------+ 6. The identification from the non scientific method that is visual identification is generally considered definitive k. True l. False +-----------------------------------------------------------------------+ | **RATIONALE** | | | | ANSWER: A | | | | - **Visual Identification** | | | | - 🖊️Definitive, Presumptive --- in certain circumstances because of | | the limitations. | | | | - **By someone with personal knowledge** about the decedent's | | appearance.  | | | | - **The most common method** ---*involves a person who knows the | | deceased saying "Yes, this is the person that I know".*  | +-----------------------------------------------------------------------+ 7. It is possible to determine with accuracy the exact postmortem interval with application of all known methods to forensic science a. True b. False +-----------------------------------------------------------------------+ | **RATIONALE** | | | | ANSWER: B | | | | - **Estimation of Postmortem Interval** | | | | - "None of the methods used in establishing PMI are totally | | reliable and mathematically precise. Dogmatic and pinpoint | | accuracy...is not achievable. \[But taking all these methods | | and environmental and individual influences into | | consideration\] frequently permit determination of a | | realistic range of PMI." | +-----------------------------------------------------------------------+ 8. Compared to females, males have generally shorter pubic bones relative to their ischial bone. a. True b. False +-----------------------------------------------------------------------+ | **RATIONALE** | | | | ANSWER: A | | | | - **Ischiopubic Index** | | | | - Male - \ a. True b. False +-----------------------------------------------------------------------+ | **RATIONALE** | | | | ANSWER: A | | | | - 🖊️DNA Analysis is King in Forensic Identification, nowadays; | | taken over dental analysis. | | | | - The DNA profile is unique to each person, except in monozygotic | | twins | +-----------------------------------------------------------------------+ 10. Infants tend to mummify more than adults. a. True b. False +-----------------------------------------------------------------------+ | **RATIONALE** | | | | ANSWER: A | | | | - Mummification tends to be seen in **fetuses or newborn infants** | | | | - 🖊️*Due to their peculiar low mass-to-surface area ratio → | | makes evaporation and desiccation easier* | +-----------------------------------------------------------------------+ REFERENCES {#references.TransOutline} ========== - Batch 2025 COM Transcription - Atty. Kristienne O. Apostol, MD (2024). Decomposition of Human Remains APPENDIX ======== - No appendices