Professor Lawrence's Lecture on Anatomy and Physiology

Introduction

• Lecture by Professor Lawrence for human anatomy and physiology at Del Mar College.
• Videos created due to COVID-19 shutdown, converted from face-to-face to online.
• Lecture series nearing completion for the semester.

Nervous System Overview

• Previous topics covered include:
  • Neuron function
  • Action potentials
  • Synaptic activity
  • Importance of understanding action potentials and neurotransmitters for health careers.

Brain and Spinal Cord

• Basic functions of brain structures.
• Anatomy and physiology of the spinal cord discussed.
• Topics include: ventricles, cerebrospinal fluid, meninges.

Chapter 15: Neural Integration

• Integration: Combining sensory inputs (sight, sound, smell, taste, touch, vibration, temperature, pain) for decision making.
• Key Functions:
  • Survival as individuals and species.
  • Avoid predators, find food, and reproduce.

Neural Pathways

• Sensory pathways involve series of three neurons:
  • First Order Neuron: From periphery to spinal cord.
  • Second Order Neuron: From spinal cord to brain (typically thalamus).
  • Third Order Neuron: From brain to sensory cortex.

Definitions

• Stimulus: Detectable change in environment; alters resting potential of first-order neuron.
• Sensation: Strong stimulus that reaches CNS; alters resting potential of second-order neuron.
• Perception: Conscious awareness of a sensation.

Sensory and Motor Tracts

• A Sending Tracts (Sensory):

  • All sensory pathways ascend to the brain.
  • Example Tracts:
    • Spinothalamic tracts (pain, temperature, crude touch)
    • Spinocerebellar tracts (proprioception, coordination)
    • Fasciculus cuneatus and gracilis (fine touch, pressure)

• Descending Tracts (Motor):

  • Begin in brain and send motor commands to spinal cord and muscles.
  • Example Tracts:
    • Corticospinal tracts (cortex to spinal cord)
    • Corticobulbar tracts (facial muscle control)
    • Vestibulospinal and Tectospinal tracts (balance, coordination)

Conclusion

• Understanding sensory and motor pathways is crucial for physiology.
• Integration of information from different sensory inputs is key for survival.
• Upcoming lecture will cover the autonomic nervous system in more detail.