BMS Funeral Service Microbiology and Pathology 3 — Questions and Answers
Question 1: Autolysis in postmortem tissue is primarily driven by:
- External bacterial invasion
- Release of intracellular lysosomal enzymes (Correct answer)
- Oxidative damage from atmospheric oxygen
- Viral replication within cells
Correct answer: Release of intracellular lysosomal enzymes
Autolysis is self-digestion of cells caused by release of lysosomal hydrolytic enzymes after cell death, independent of bacteria.
Question 2: Which blood-borne pathogen has the highest environmental stability and can survive on dry surfaces for up to seven days?
- HIV
- Hepatitis C Virus
- Hepatitis B Virus (Correct answer)
- HTLV-1
Correct answer: Hepatitis B Virus
Hepatitis B Virus (HBV) can persist on environmental surfaces for up to 7 days, making it a significant occupational exposure risk for embalmers.
Question 3: Caseous necrosis, characterized by a cheese-like gross appearance, is most classically associated with which disease process?
- Myocardial infarction
- Tuberculosis (Correct answer)
- Wet gangrene
- Amyloidosis
Correct answer: Tuberculosis
Caseous necrosis is a form of coagulative necrosis with cheese-like consistency, most characteristic of granulomas in tuberculosis.
Question 4: Which personal protective equipment is specifically recommended when embalming a decedent known to have active pulmonary tuberculosis?
- Standard surgical mask only
- N95 respirator or higher (Correct answer)
- A face shield with no respiratory protection needed
- Positive pressure respirator is not required
Correct answer: N95 respirator or higher
An N95 or higher respirator is required when working with TB-positive decedents to prevent inhalation of aerosolized Mycobacterium tuberculosis.
Question 5: Livor mortis is caused by:
- Bacterial gas production in blood vessels
- Pooling of blood in dependent vessels due to gravity after circulation ceases (Correct answer)
- Oxidation of hemoglobin to methemoglobin
- Coagulation of blood throughout all vessels equally
Correct answer: Pooling of blood in dependent vessels due to gravity after circulation ceases
Livor mortis (hypostasis) results from gravitational settling of blood into dependent capillaries and venules after the heart stops.
Question 6: The Ziehl-Neelsen stain is used in microbiology to identify organisms that are:
- Gram-positive cocci
- Acid-fast bacteria with waxy cell walls (Correct answer)
- Spore-forming anaerobes
- Fungal hyphae
Correct answer: Acid-fast bacteria with waxy cell walls
The Ziehl-Neelsen (acid-fast) stain identifies acid-fast bacteria like Mycobacterium species, which resist decolorization due to their mycolic acid-rich cell walls.
Question 7: Wet gangrene differs from dry gangrene primarily because it involves:
- Only arterial occlusion without venous involvement
- Superimposed bacterial infection causing liquefactive necrosis (Correct answer)
- Coagulative necrosis without microbial involvement
- Only peripheral extremities
Correct answer: Superimposed bacterial infection causing liquefactive necrosis
Wet gangrene involves bacterial superinfection of ischemic tissue, causing liquefactive necrosis with a moist, malodorous presentation.
BMS Funeral Service Microbiology and Pathology 3
Autolysis in postmortem tissue is primarily driven by: