Debunking Myths About the Human Body Post-Mortem

Introduction

• Common myths about the human body after death
• Series to address these myths
• Recognition of body donors for their contribution to science and education

Myth #1: Hair and Nails Continue to Grow After Death

• Skin Dissection Example:
  • Left scalp dissection with hair visible
  • Donor body from December 2012, zero hair growth observed
• Hair Growth Basics:
  • Hair shaft: part of the hair outside the skin
  • Hair root: part inside the follicle
  • Bulb: base of the follicle with important structures
    • Hair matrix: layer of germinal cells that grow and divide
    • Papilla of the hair: contains capillaries for nutrient supply
  • Blood supply cessation stops hair growth after death
• Similarities with Nails:
  • Nail anatomy: main portion of the nail, nail root, and nail matrix
  • Blood supply is crucial for cell division and nails' growth
  • Conclusion: No continuation of hair or nail growth post-mortem

Myth #2: Bodies Sitting Up in the Morgue

• Not possible as substantial muscle contractions are required
• Muscle Contraction Basics:
  • Motor cortex signals required to engage muscles like abdominal and hip flexors
• Rigor Mortis:
  • Concept of muscles stiffening after death
  • General physiology of muscle contraction
  • Microscopic view of muscle fibers (sarcomeres)
  • Role of calcium and ATP in muscle contraction and relaxation
  • Rigor mortis basics:
    • Initial muscle tension for about 3-4 hours
    • Complete relaxation within 24 hours due to protein degradation
  • Summary: Not enough force from rigor mortis to cause a body to sit up

Additional Information

• Importance of understanding muscle growth and repairing: more sarcomeres lead to greater muscle strength
• Encouragement to learn scientific thinking and critical analysis through coursework (sponsored content for Brilliant learning platform)

Conclusion

• Importance of debunking myths
• Learning how to think critically in pursuit of scientific truth