PSYC 001 Chapter Notes - Chapter 2: Frontal Lobe, Pituitary Gland, Reuptake
Neuropsychology
● The Structure of the Neuron
○ Neuron: responsible for transferring information through the nervous system
■ Glial Cells (glia): Support system for the neurons. Gets rid of its waste
products, keeps its chemical environment stable, and insulates them from
harm so they can be more efficient.
● About a 1:1 ratio of nueron/glia. Glia communicate with both the
neurons and each other
● Influences the strength of nueronal connections, so plays an
important role in schizophrenia, depression, and
neurodegenerative diseases (Parkinson’s, Alzheimer’s).
■ Dendrites: fibers that branch out of the cell body and receive information
from other neurons and passes it onto the cell body.
■ Cell Body: Contains the nucleus of the cell and everything that keeps it
alive. Decides whether or not to pass on info from the dendrites to other
neurons through the axon.
■ Axon: Long, single fiber that leaves the cell body. At the end it divides
into little branches (axon terminals). The axon conducts info from the cell
body to the terminals, which transmit it to other neurons. Protected by the
myelin sheath.
■ Myelin Sheath: An layer of fatty white substance (made of glial cells) that
insulates the axon. Looks like little sausage links.
● Builds up in the most used part of the brain and makes it look
“white” as opposed to gray. Difference between white matter and
gray matter.
●Multiple sclerosis: causes an attack on the myelin sheath and
makes brain/body communication slower.
○ How Neurons Communicate: Information traveling within the neuron is
electrical, but going between neurons is chemical.
■ Electrical Impulses
● Excitatory/Inhibitory: The cell body decides to generate or not
generate an electrical impulse (to send or not send info down the
axon).
● Stronger stimuli (a slap vs. a pat) causes more neurons to
generate electrical impulses, and more often.
● Axons that are encased in a myelin sheath also travel much faster.
Instead of the electrical current running continuously down the
axon, it “leaps” from the gap to gap of the sheath.
■ Chemical Communication
● Axon Terminals: has tiny sacs on the ends that contain
neurotransmitters
● Neurotransmitter: a chemical in our nervous system that
specializes in transmitting information.
○ When the electrical current reaches the axon terminal, it
causes the sacs to open and release the transmitters into
the synapse
● Synaptic Gap: the tiny gaps between neurons
○ Then the neurotransmitters fit perfectly into the dendrite
receptors.
○ After that, they either get destroyed by enzymes, or send
back to their axon terminal and re-used (re-uptake).
● Brain Scans: The brain actually uses 20% of the body’s blood
supply (nutrients in blood sugar and oxygen).
○PET (Positron Emission Tomography) Scans: injects
radioactive glucose (sugar) into bloodstream, moves to the
most active parts of the brain, gets metabolized by the
neurons, and released “positrons” which light up on the
computer. Bright colors in more active places.
○ MRI Scan: Less invasive. Measures the amount of
oxygen brought to active areas in the brain through blood
flow. Shows an even clearly image of brain activity.
● Neurotransmitters, Drugs, and Poisons
○ Agonist vs. Antagonist: Agonist increases the activity of
neurotransmitters, antagonists decreases activity.
○Acetylcholine: A kind of neurotransmitter involved in learning, memory,
and muscle movement.
■ Alzheimer’s patients have high levels of this. Poisons that block it
lead to paralysis
■ Black widow spiders venom overflows the synapse with ACh
(convulsions) until it runs out and causes paralysis
○ Dopamine: Impacts arousal, mood, and physical movement
■ Having low levels of dopamine can lead to Parkinson’s disease
and causes movement problems
● This is when dopamine can’t get through the blood-brain
barrier (the brain is trying to keep dangerous chemicals
out) even though it’s good
● L-dopa is a drug that can trick the brain and help for a little
while but it has side effects like schizophrenia (too much
dopamine in brain).
■ Cocaine: blocks the reuptake of dopamine so that is accumulates
in the synapse and repeatedly delivers the message to the same
neurons
■ Amphetamines: continually stimulates the release of dope until it
runs out
○ Serotonin & norepinephrine: involved in arousal, mood, sleeping, and
eating.
Document Summary
Neuron: responsible for transferring information through the nervous system. Glial cells (glia) : support system for the neurons. Gets rid of its waste products, keeps its chemical environment stable, and insulates them from harm so they can be more efficient. Glia communicate with both the neurons and each other. Influences the strength of nueronal connections, so plays an important role in schizophrenia, depression, and neurodegenerative diseases (parkinson"s, alzheimer"s). from other neurons and passes it onto the cell body. Dendrites: fibers that branch out of the cell body and receive information. Cell body : contains the nucleus of the cell and everything that keeps it alive. Decides whether or not to pass on info from the dendrites to other neurons through the axon. Axon : long, single fiber that leaves the cell body. At the end it divides into little branches (axon terminals). The axon conducts info from the cell body to the terminals, which transmit it to other neurons.
