Lecture on the Nervous System

Overview of the Nervous System

• Primary relationship between body and mind.
• Misconception: Mind often equated with the brain.
• Role of the Nervous System: Regulates emotions and reactions, e.g., 'hangry' feeling.

Functions of the Nervous System

1. Receive inputs from the environment.
2. Process and integrate with past experiences.
3. Generate output through behavioral responses.

Neurons and Communication

• Neurons: Specialized cells for sending and receiving messages.
  • Neurons are like mailboxes, neurotransmitters are the mail, and action potentials are the mailman.
• Glial Cells: Support neurons by providing nutrients and oxygen.
• Neuron Structure: Soma (cell body), dendrites (receive signals), axon (transmit signals), myelin sheath (increases speed of communication).
• Synapse: Gap between neurons where neurotransmitters travel.

Neurotransmitters

• Chemicals that transmit signals across the synapse.
• Dopamine: Involved in movement, pleasure, and reward. Can be excitatory or inhibitory.
• Serotonin: Generally inhibitory, regulates mood, anxiety, and physiological functions.
• Neurotransmitter Functions: Excitatory (propagate signals) vs inhibitory (halt signals).

Dopamine

• Plays a role in movement, pleasure, and addiction.
• Associated with motivation and goal achievement.

Serotonin

• Regulates mood, appetite, and sleep.
• Linked to depression and anxiety.

Peripheral Nervous System

• Somatic Nervous System: Controls sensory and motor functions.
  • Sensory Pathway: Connects senses to the brain.
  • Motor Pathway: Sends signals from brain to muscles.
• Autonomic Nervous System: Controls involuntary functions (e.g., heart rate, digestion).
  • Sympathetic System: Fight or flight responses.
  • Parasympathetic System: Rest and digest responses.

Central Nervous System

• Spinal Cord: Connects brain to peripheral system; can conduct simple reflexes.

Psychological Implications

• Mental Health Disorders: ADHD, depression linked to neurotransmitter levels.
• Environmental Impact: Understanding neurotransmitter actions can inform behavioral changes.

Summary

• The nervous system is complex, with neural communication being vital to body function.
• Understanding neurotransmitters like dopamine and serotonin helps explain behavior and psychological states.
• The balance between different nervous systems (peripheral and central) influences overall health and psychological well-being.