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Chapter 3
Notes
AP Tips
Know the basic structure of a
neuron
 Dendrites receive information from
adjacent neurons; process incoming
chemicals and propel info to the nucleus
 The axon is the neural fiber that transmits
info from the soma to the other end of the
neuron; encased by myelin, a fatty
substance that protects info stored inside
the axon
 The axon terminal is the ending part of the
neuron that releases information
Know the types of neurons
 Sensory (afferent) neurons transmit
info from the spinal cord to the brain;
they help our brains register sensory
information
 Motor (efferent) neurons transmit info
from the brain to muscles and glands
 S.A.M.E.
 Be familiar with the process of neural
transmission—specifically, the all-ornone principle, and know which ions
enter and exit during polarization and
depolarization.
Order of events in the firing of a
neuron
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Polarization
Resting potential
Depolarization
Action potential
Threshold
All-or-none principle
Refractory period
Polarization
 Negatively charged chloride ions exist
within the axon, resulting in a
negative charge.
Resting potential
 Negatively charged ions wait for
stimulation within the axon. The
neuron is said to be inactive and is
waiting for another action potential.
Depolarization
 When stimulated, the channels along
the axon allow positively charged
sodium and potassium ions to enter.
This causes sodium and potassium
channels to open, thus propelling the
electrochemical process down the
axon.
Action potential
 A change in the balance of the overall
charge of the neuron causes the
electrochemical signal to travel ( it is
fired) along the axon.
Threshold
 A point of excitation on the neuron
that must be reached for an action
potential to occur
All-or-none principle
 Once the threshold is reached, the
neuron will fire at full strength. If the
threshold is not reached, the neuron
will not fire.
Refractory period
 The period after a neuron fires, at
which time it is less susceptible to
stimulation from other neurons. The
neuron must recharge itself
electrically until it reaches
polarization. Once this occurs, the
neuron is ready to fire again.
Know about specific
neurotransmitters and the resulting
effects of an excess or a deficiency.

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
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Acetylcholine
Dopamine
Serotonin
GABA
Norepinephrine
Glutamate
Know the organization of the
nervous system
 Central Nervous System
 Peripheral Nervous System
 Autonomic Nervous System
Central Nervous System (CNS)
 Responsible for processing and
distributing information throughout
the body
Brain
 Responsible for cognitive functioning
Spinal Cord
 Responsible for transmitting
information throughout the body.
Peripheral Nervous System (PNS)
 Responsible for voluntary movement
and regulation of vital processes.
Somatic Nervous System
 Responsible for voluntary movement
Autonomic Nervous System
 Regulation of vital human functioning
(breathing, digestion, heartbeat, etc)
Sympathetic Nervous System
 Spends reserved energy
Parasympathetic Nervous System
 Restores and repairs spend energy
Know about the 4 brain lobes
 Frontal lobe: responsible for
controlling inhibitions, short-term
memory, reasoning, and planning for
the future
 Parietal lobe: responsible for
receiving and combining tactile
(touch) stimuli from all over the body
to allow the formation of a single
concept.
 Occipital lobe: responsible for
processing visual stimuli, as well as
maintaining balance
 Temporal lobe: responsible for
processing auditory stimuli
Be able to identify the functions of
Broca’s and Wernicke’s areas.
 Broca’s area: responsible for
transferring thoughts into audible
spoken words
 Wernicke’s area: responsible for
transforming spoken words into
thoughts
Know the location and functions of
brain structures
 Complete table
Know the area of the brain
responsible for hunger.
 Hypothalamus
Know how psychologists look into
the brain.
 EEG: electrodes are placed on the
scalp to measure the brain’s electrical
activity
 CT or CAT Scan: produces a 2-dim
image based on x-rays taken around
a single axis
 MRI: uses a large magnetic field to
reconstruct the image within the
body/brain
 fMRI: measures neural activity within
the brain
 PET scan: uses radioactive liquid to
measure metabolic and glucose
processing (3-dim view)
Know the major glands, their
hormones, and their functions
 Complete table