Lecture on Involuntary Human Body Functions

Introduction

• Concept: The human body as a "mech suit" controlled by the brain.
• Control: Only 25% of body functions are under direct control (voluntary movement and sensory perception).
• Autonomous Functions: Majority of bodily functions are autonomously controlled by biomechanical systems.

Five Weird Involuntary Body Functions

1. Hypnic Jerk

• Description: Sensation of falling while falling asleep.
• Cause: Brain misinterprets muscle relaxation as potential danger (falling/dying).
• Function: Brain sends a jolt to "wake" the body.
• Factors: More frequent if sleep-deprived or stressed.

2. Yawning

• Function: Involuntary respiration increasing oxygen intake and expelling CO2.
• Contagiousness: Social mirroring causes people to yawn when they see others yawn.
• Purpose: Possibly a group behavior to encourage deep breathing.

3. Crying

• Types:
  • Reflex Tears: Remove irritants like smoke and acids.
  • Emotional Tears: Contain additional proteins and hormones.
• Theories:
  • Stress Relief: Crying helps relieve stress.
  • Social Empathy: Evokes empathy and attracts support.

4. Pruning of Fingers

• Misconception: Grownups often use pruning as a reason to exit water.
• Function: Occurs within 15 minutes to help grip objects underwater.
• Concern: No harm unless submerged for over 12 hours.

5. Shivering

• Function: Muscles contract and relax rapidly to generate heat.
• Comparison to Exercise: Shivering uses energy and promotes fat loss.
• Hormone Produced: Irisin, which helps with glucose tolerance and preventing diabetes.
• Limitations: Not a sustainable weight loss method, as body adapts over time.

Conclusion

• Autonomous Systems: Human body hosts numerous background functions like breathing.
• Awareness: Understanding involuntary functions can bring awareness to our body's complex systems.

Note: Speaker references themselves as a cartoon character, humorously noting they don't need to breathe.