What is a Viscera | Classification, collection and preservation techniques in Forensic

In fatal cases of poisoning or unnatural death instead of murder, the viscera hold prominent grounds in uncovering the telltale from the hidden incidents.

FORENSIC SCIENCEFORENSIC TOXICOLOGY

Shubham Kumar

1/29/20245 min read

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In fatal cases of poisoning or unnatural death instead of murder, the viscera hold prominent grounds in uncovering the telltale from the hidden incidents. The viscera refers to the internal organs to be collected for the investigation purposes after the death of victim. Notably, the investigation of usually done by the forensic toxicologists and is one of the most promising factor in proving valuable insights about the crime.

In this article we are going to gain valuable insights on viscera, knowing its types and how its collected, preserved and documents.

Viscera | Definition

In the context of forensic toxicology, viscera refer to the internal organs situated within the thoracic and abdominal cavities of the body. These organs encompass a range of vital structures, including the heart, lungs, liver, spleen, kidneys, stomach, intestines, and bladder, among others. During a post-mortem examination, commonly known as an autopsy, forensic pathologists carefully extract and preserve these organs for subsequent toxicological analysis.

The analysis of viscera samples extracted during an autopsy provides valuable insights into the presence and effects of drugs, chemicals, or toxins within the body. Samples obtained from organs such as the liver, kidney, or stomach contents offer critical information regarding the absorption, distribution, metabolism, and excretion of substances, as well as their potential toxic effects.

Forensic toxicologists employ a range of techniques to analyze viscera samples and identify toxic substances. These techniques include screening tests, immunoassays, and instrumental analysis using sophisticated instruments like gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS). Through these analyses, forensic toxicologists can determine the presence, concentration, and identification of drugs, alcohol, poisons, or other toxic substances in the body.

Role of Viscera in Toxicological Analysis

The analysis of viscera samples extracted during an autopsy provides valuable insights into the presence and effects of drugs, chemicals, or toxins within the body. Samples obtained from organs such as the liver, kidney, or stomach contents offer critical information regarding the absorption, distribution, metabolism, and excretion of substances, as well as their potential toxic effects.

Techniques in Viscera Analysis

Forensic toxicologists employ a range of techniques to analyze viscera samples and identify toxic substances. These techniques include screening tests, immunoassays, and instrumental analysis using sophisticated instruments like gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS). Through these analyses, forensic toxicologists can determine the presence, concentration, and identification of drugs, alcohol, poisons, or other toxic substances in the body.

Classification of Viscera

The classification of viscera is an essential aspect of forensic toxicology, enabling a systematic examination and analysis of internal organs during forensic investigations. The classification of viscera is based on their anatomical location and their relevance to toxicological analysis. The following are the common classifications of viscera:

Thoracic Viscera:

Thoracic Viscera: This category includes the organs situated within the thoracic cavity, encompassing the heart, lungs, trachea, bronchi, and esophagus. Forensic toxicologists primarily examine thoracic viscera in cases involving respiratory-related issues, inhalation of toxic gases, or suspected poisoning through ingestion.

Abdominal Viscera:

The abdominal cavity houses several crucial organs involved in digestion, metabolism, and detoxification. Abdominal viscera comprise the liver, spleen, stomach, small and large intestines, kidneys, gallbladder, pancreas, and urinary bladder. The examination of abdominal viscera plays a significant role in assessing the effects of toxic substances on these organs and their contribution to the cause of death. Moreover, it aids in the analysis of drug absorption, distribution, metabolism, and excretion.

Cranial Viscera:

Cranial Viscera: The cranial viscera consist of organs located within the cranial cavity, primarily housing the brain. In forensic toxicology, the brain is of utmost importance in cases involving suspected drug overdose, neurotoxicity, or traumatic brain injuries. By examining the brain and its associated structures, forensic toxicologists can gain valuable insights into the effects of drugs or toxins on the central nervous system.

Genital Viscera:

Genital Viscera: This category encompasses the reproductive organs, including the uterus, ovaries, testes, prostate gland, and associated structures. Forensic toxicologists examine genital viscera primarily in cases involving sexual assault, suspected drug-facilitated crimes, or toxicological analysis related to reproductive health.

Collection and Documentation of Viscera

In the field of forensic toxicology, the collection and preservation of viscera are pivotal steps that safeguard the integrity and suitability of samples for subsequent toxicological analysis. Thorough handling of viscera during post-mortem examinations and the implementation of proper preservation techniques are paramount to maintaining sample integrity, thereby preventing degradation or contamination.

Collection Procedure

The collection of viscera typically transpires during post-mortem examinations performed by experienced forensic pathologists. To minimize the risk of damage or contamination, pathologists exercise meticulous care when extracting organs from the thoracic and abdominal cavities. Each organ is collected individually and handled separately to prevent any potential cross-contamination. Concurrently, it is imperative to document the condition and appearance of the organs during the collection process, taking note of any abnormalities or injuries encountered.

Packaging and Labeling

To ensure the preservation of sample integrity and prevent any mix-ups, each organ is meticulously placed in a separate, suitably labeled container or packaging. The selection of containers depends on the specific organ and preservation requirements, often involving leak-proof jars, plastic bags, or sterile vials. Proper sealing and labeling of containers with relevant information such as the case number, date, organ type, and other pertinent details are essential for accurate identification.

Chain of Custody

Meticulous documentation throughout the collection and preservation process is imperative to maintain an unbroken chain of custody. Detailed records of the collection, packaging, sealing, and labeling of viscera should be upheld, including the names and signatures of all individuals involved in each

Preservation Methods

The choice of preservation method hinges upon the unique requirements of each case and subsequent toxicological analyses to be conducted. Three commonly employed preservation methods include refrigeration, freezing, and chemical fixation:

a. Refrigeration: Viscera can be refrigerated within the temperature range of 2 to 8 degrees Celsius (36 to 46 degrees Fahrenheit). Refrigeration serves to retard microbial growth and enzymatic activity, preserving the samples for a limited period of time.

b. Freezing: Freezing viscera at temperatures below -20 degrees Celsius (-4 degrees Fahrenheit) facilitates long-term preservation, effectively impeding degradation and microbial growth. It is crucial to employ suitable containers and ensure proper insulation to prevent freezer burn or frost damage.

c. Chemical Fixation: In specific cases where histopathological analysis is necessary, the viscera may undergo preservation in a fixative solution such as formalin. Chemical fixation aids in preserving tissue structure and cellular morphology, thus enabling subsequent microscopic examination.

This blog has achieved its aim to provide you insights about the viscera, its types and how its collected, preserved and documents.

Reference

  • "Forensic DNA Typing" by John M. Butler

  • "The Forensic Casebook: The Science of Crime Scene Investigation" by Ngaire E. Genge

  • "Forensic Science: A Very Short Introduction" by Jim Fraser

  • "Practical Crime Scene Processing and Investigation" by Ross M. Gardner