Psychology chapter 3 part 1 02/20/2025

Overview of Chapter

• Focus: Structure and function of the brain, particularly neurons.

• Quote Explanation:

  • "The astonishing hypothesis is that you are nothing but a pack of neurons."

  • Implicates that human behavior, emotions, and personal identity stem from neuronal activities and chemical interactions in the brain.

Neurons: Basic Structure and Function

• Definition: Neurons are the basic building blocks of the brain, communicating electrochemically.

• Key Functions:

  • Messages sent within a neuron are electrical.

  • Messages sent between neurons are chemical.

Components of Neurons

1. Dendrites

   • Function: Receive information and send signals to the cell body.

2. Cell Body

   • Function: Builds energy, removes waste, and contains the nucleus.

   • Nucleus: Houses DNA, essential for the neuron's function.

3. Axon

   • Function: Transports information from the cell body to terminal branches (analogous to an escalator).

4. Myelin Sheath

   • Function: Speeds up message transmission along the axon.

   • Health Implications: Lack of myelin is linked to conditions like Multiple Sclerosis (MS).

Transmission of Signals

• Electrical Communication:

  • Occurs within the neuron from dendrites to terminal buttons through ion movement.

• Chemical Communication:

  • Occurs between neurons at the synapse, involving neurotransmitter release.

  • Important questions for exams can include:

    • What type of communication occurs within neurons? Answer: Electrically

    • What type of communication occurs between neurons? Answer: Chemically

Understanding Myelin and Disease

• Multiple Sclerosis (MS):

  • An autoimmune condition where the body attacks its own myelin, leading to motor function issues.

  • Exam focus on symptoms linked to myelin damage.

Chemical Transmission between Neurons

• Synapse: The gap between neurons where chemical transmission occurs.

• Neurotransmitter Release:

  • Vesicles containing neurotransmitters release them into the synapse.

  • Neurotransmitters can either be accepted by the receiving neuron or regulate various brain functions.

Consequences of Chemical Communication

• Effects of Drugs: Substances like cocaine and caffeine manipulate neurotransmitter functions, influencing mood and behavior.

Conclusion

• Key topics to review for exams:

  • Structure and functions of neurons (dendrites, cell body, axon, myelin).

  • Understanding the difference between electrical and chemical communication.

  • Impact of neurotransmitters in the synapse, including drug interactions.