Understanding Nervous and Endocrine Systems

Oct 5, 2024

Crash Course Psychology: Nervous and Endocrine Systems

Introduction

  • Example of fear response: sudden noise at night.
  • Brain releases chemicals leading to fight or flight response.
  • Emphasizes that psychological events are biological in nature.

Understanding Neurons

  • Neurons: Building blocks of the nervous system.
    • Electrochemical cells transmitting messages.
    • Variety: From millimeter-long brain neurons to leg-spanning neurons.
  • Structure of Neurons:
    • Soma (Cell Body): Contains nucleus, DNA, mitochondria, etc.
    • Dendrites: Receive signals from other neurons.
    • Axon: Transmits signals to other neurons, glands, or muscles.
    • Myelin Sheath: Insulates axon, speeds up signal transmission.
  • Synapses:
    • Chemical messengers (neurotransmitters) cross synaptic gap to receptors.
    • Reuptake process: Neurotransmitters reabsorbed by releasing neuron.

Role of Neurotransmitters

  • Types of neurotransmitters:
    • Excitatory: Increase likelihood of neuron firing (e.g., Norepinephrine, Glutamate).
    • Inhibitory: Decrease neuron firing (e.g., GABA, Serotonin).
  • Effects:
    • Influence emotions, actions, and physiological responses.
    • Associated with disorders (e.g., low serotonin with depression).

Hormones and the Endocrine System

  • Hormones: Chemical messengers similar to neurotransmitters but travel through the bloodstream.
    • Affect mood, arousal, metabolism, and reproduction.
    • Provide longer-lasting effects than neurotransmitters.
  • Key Glands and Hormones:
    • Adrenal Glands: Secrete adrenaline for fight or flight response.
    • Pancreas: Regulates sugar absorption with insulin and glucagon.
    • Thyroid/Parathyroid: Monitor metabolism and calcium levels.
    • Testes/Ovaries: Secrete sex hormones.
    • Pituitary Gland: Master gland controlling other glands, releases growth and oxytocin hormones.

Nervous and Endocrine System Interaction

  • Feedback loop: Nervous system directs endocrine, which influences nervous system.
    • Brain, gland, hormone, brain cycle.
  • Sensory inputs trigger responses without conscious control.

Future Topics

  • Next lesson: deeper exploration of nervous system components and brain usage.

Closing Credits

  • Acknowledgments to contributors and sponsors.

These notes summarize key points from the lecture on how our nervous and endocrine systems collaborate to influence our psychological and biological functions.