Chapter 2 – Neurons

Psychobiology links ______

I. Two Systems That Influence Behavior

1)Nervous System:

______- brain and spinal cord

______- network of nerve cells

2)Endocrine System:

Network of ______that release ______into the bloodstream

II. Neurons (basic building blocks of the brain and nervous system)

A. Composition of Neurons

1) ______- individual nerve cell

B. Parts of the Neuron:

2)______- remaining cells in nervous system

Perform ______functions

-Nourishment

-Remove wastes/toxins

-Aid neural function?

-Form ______

(Olgiondendrocytes & Schwann cells)

C. Types of Neurons

1)______(______) Neurons – carry signals ____ the brain & spinal cord

2) ______(______) Neurons – carry signals ______the brain & spinal cord

3) ______(______) Neurons – carry signals ______each other

Keep in Mind!

●Neurons ______in size & shape but all have the ______parts (___-______)

●______is another word for the ______

●Axons = ______/ Dendrites = ______

●Not all neurons have a ______

-If they do, it ______

● Types of Neurons = ______• ______(approach • exit)

III. Neural Impulses

  1. The neuron, at rest, has a ______and is in a state of

______(______) with a ______

- The neuron of a resting neuron is more negatively charged than the outside because ofthe negative ions within the cell

- The axon has ion channels (like gates) that are closed, preventing the flow of these ions into and out of the axon; it is ______

  1. ______

- Once the required ______is met ( ______)

the neuron will fire

- If the stimulus goes above this threshold the neuron will still fire the same way and at

the same intensity

- If the threshold is not met, then the neuron ______

C. The shift in ion flow and charge results in an electrical impulse (lasting about one thousandth

of a second) that flows through the axon called the ______(______)

- If stimulated enough (neurotransmitters are exchanged), the ______

ismet and the process begins - the neuron becomes ______and the

positive ions from outside rush into the cell which is called ______

- The change progresses down the ______causing the neural ______

  1. After firing the neuron recovers and ______and

______– this is called the ______

- The positively charged sodium ions are pumped out of the neuron

(______) and potassium flows back in

Keep in Mind!

● ______(______) = ready to fire

●______(exchange that pushes the electrical signal through

the axon)

●______(______) = firing

●______(______) = “re-setting”

● Neurons that have ______experience ______action potentials

●The______must be met or exceeded for a neuron to fire. It is an

______

IV. Neural Transmission (______transduction)

  1. There is a ______(called a ______or Synaptic Gap or Cleft) between terminal branch of one neuron and dendrite of another
  1. When the ______of the sending neuron reaches the end of the______, ______(chemicals that give different ______)are released into the synapse from ______( ______)
  2. The end of the ______of the receiving neuron has many ______that accept ______of neurotransmitters[think of it as a key (neurotransmitter) and lock (receptor site)]

- If the threshold is met, then the receiving neuron will fire

  1. ______is when extra released neurotransmitters are ______

______

- They are broken down by mono-amine-oxidase or ______ (“one protein enzyme”)

- ______(like antidepressants) ______

______of neurotransmitters keeping more in the synapse

(______)

V. General Types of Neurotransmitters

* See “Neurotransmitter” Handout

  1. ______Neurotransmitters = chemicals that tell the receiving neuron ______
  1. ______Neurotransmitters = chemicals that tell the receiving neuron ______
  1. ______= chemicals that have more ______on neurons & the brain in general

- ______= natural chemicals that are released to ______

______ (like a natural opiate)

VI. Effects of Neurotransmitters

A. ______are aclass of chemicals that can either ______neurotransmitters, ______of extra neurotransmitters, or ______of neurotransmitters (“Agonists excite”)

- Examples:

●Opiates(Morphine, Heroine, etc.) – mimic neurotransmitters to produce amplified highs

● Black Widow Spider Venom – produces Acetylcholine causing violent muscle contractions and convulsions

B. ______are a class of chemicals that can either ______the neurotransmitters from their receptor sites or can______of the neurotransmitter (“Antagonists inhibit”)

- Examples

●Advil – binds to Substance P receptor sites and prevents pain

● Botox (Botulin) – prevents the release of Acetylcholine

●Curare – binds to Acetylcholine receptor sites and prevents Acetylcholine from getting into receiver neuron

Keep in Mind!

● ______are chemicals that send signals

- Excitatory = ______

- Inhibitory = ______

● Reuptake = ______

● Agonists = ______ (mimic)

● Antagonists = ______(block)

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