PSY 101 – Dr. V
Chapter 2 Lecture Notes
Module 4 – Neural and Hormonal Systems
Overview of Nervous System
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Nervous System - _______________________________________________________________
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Neuroscience – deals with the structure and function of the brain and the neurons, nerves, and
nervous tissue that form the nervous system.
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Relationship to behavior and learning.
Structure of the Neuron
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Neurons - ______________________________________________________________________
______________________________________________________________________________
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Parts of a Neuron
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_________________ - branch-like structures that receive messages from other neurons.
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__________ - the cell body of the neuron, responsible for maintaining the life of the cell.
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_________ - long tube-like structure that carries the neural message to other cells.
Other Types of Brain Cells
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Glial cells - grey fatty cells that:
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________________________________________________________________________
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________________________________________________________________________
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produce myelin to coat axons,
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Myelin Sheath - ____________________________________________________
_________________________________________________________________
_________________________________________________________________
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Generated by a Schwann Cell
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clean up waste products and dead neurons.
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Note: Neurons only makeup 10% of cells in the brain; the remaining 90% is glial
Neurons in the Body
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Nerves – _______________________________________________________________________
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Neurilemma – Schwann’s membrane.
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_________________________________________________________________
_________________________________________________________________
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Most axons of the neurons in the brain and spinal cord do not usually have this
coating, thus, more likely to be permanently damaged.
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PSY 101 – Dr. V
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_______________________ – disease that damages the myelin sheath (i.e.,
demyelination), which leads to a loss of function in those damaged cells.
Neuron
Generating the Message: Neural Impulse
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Ions – charged particles.
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Inside neuron – __________________________
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Outside neuron – ___________________________
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Resting potential – the state of the neuron when not firing a neural impulse.
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________________ – Each neuron receives excitatory and inhibitory signals from many neurons.
When the excitatory signals minus the inhibitory signals exceed a minimum intensity (threshold)
the neuron fires an action potential
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_______________________ - the release of the neural impulse consisting of a reversal of the
electrical charge within the axon.
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Allows positive sodium ions to enter the cell.
All-or-none – ___________________________________________________________________
______________________________________________________________________________
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Difference between strong stimulation and weak stimulation? – strong message results
in the neuron firing more quickly, and it will also cause more neurons to fire.
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________________________ – neuron is incapable of repeating (i.e., firing) until returns to
resting potential (very brief – often milliseconds)
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Return to resting potential.
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PSY 101 – Dr. V
Action Potential
Sending the Message to Other Cells
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Axon terminals - branches at the end of the axon.
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Synaptic knob (or terminal button) – rounded areas on the end of axon terminals.
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Synaptic vesicles - __________________________________________________
_________________________________________________________________
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___________________________- chemical found in the synaptic
vesicles which, when released, has an effect on the next cell.
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Synapse/synaptic gap - microscopic fluid-filled space between the rounded areas on the end of
the axon terminals of one cell and the dendrites or surface of the next cell.
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_____________________ - holes in the surface of the dendrites or certain cells of the muscles
and glands, which are shaped to fit only certain neurotransmitters.
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PSY 101 – Dr. V
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Cleaning up the Synapse
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______________ - process by which neurotransmitters are taken back into the synaptic vesicles;
applies the “breaks” on neurotransmitter action.
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Enzyme - a complex protein that is manufactured by cells.
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e.g., one type specifically breaks up acetylcholine because muscle activity needs to
happen rapidly, so reuptake would be too slow.
How Neurotransmitters Influence Us
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Serotonin pathways are involved with _______________________________________________
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_____________ pathways are involved with diseases such as schizophrenia and Parkinson’s disease.
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________________ – produce good feelings (e.g., “runner’s high”)
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explains painkilling effects of acupuncture
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explains indifference to pain when severely injured
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opiates  ______________  _____________
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when flooded with opiate drugs, the brain stops producing own natural opiates
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when drug is withdrawn, deprivation of opiates causes great discomfort
(i.e., withdrawal)
PSY 101 – Dr. V
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Neuron Communication
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Neurons must be turned ON and OFF.
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Excitatory neurotransmitter - neurotransmitter that causes the receiving cell ________
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Inhibitory neurotransmitter - neurotransmitter that causes the receiving cell ___________
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Chemical substances can affect neuronal communication: Agonists & Antagonists
Lock & Key Mechanism – neurotransmitters bind to the receptors of the receiving neuron in a
key-lock mechanism.
o
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Agonist – ________________________________________________________________
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Some opiate drugs amplify normal sensations of arousal and pleasure (i.e., “high”)
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Black widow spider venom – _____________________________________ = violent
muscle contractions, convulsions, possible death
Antagonist – _____________________________________________________________
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________ – causes paralysis by blocking ACh release; can come from improperly
canned food
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
__________________ – smoothes wrinkles by paralyzing the underlying
facial muscles
Some antagonists will occupy receptor sites and block its effect; similar to the
natural neurotransmitter, but not similar enough to stimulate the receptor
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__________ – a poison that can be applied to hunting-dart tips
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Occupies and blocks ACh receptor sites, which does not allow
the neurotransmitter to affect the muscles = paralysis
PSY 101 – Dr. V
The Nervous System
Central Nervous System
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Central nervous system (CNS) - ____________________________________________________
______________________________________________________________________________
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Spinal cord - a long bundle of neurons that carries messages to and from the body to
the brain that is responsible for very fast, lifesaving reflexes.
The Reflex Arc: Three Types of Neurons
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Sensory neuron - ________________________________________________________________
______________________________________________________________________________
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Motor neuron - _________________________________________________________________
______________________________________________________________________________
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Also called _____________________
Also called _____________________
__________________ - a neuron found in the center of the spinal cord that receives information
from the sensory neurons and sends commands to the muscles through the motor neurons.
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This _________________ skips going to the brain – like a shortcut
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Interneurons also make up the bulk of the neurons in the brain.
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PSY 101 – Dr. V
The Spinal Cord & Reflexes
Peripheral Nervous System
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Peripheral nervous system (PNS) - __________________________________________________
______________________________________________________________________________
______________________________________________________________________________
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Somatic nervous system
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Autonomic nervous system
Somatic Nervous System
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Soma = body.
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Somatic nervous system - ________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
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Sensory pathway - nerves coming from the sensory organs to the CNS consisting of
sensory neurons.
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Motor pathway - nerves coming from the CNS to the voluntary muscles, consisting of
motor neurons – i.e., skeletal muscles
Autonomic Nervous System
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Autonomic nervous system (ANS) - division of the PNS consisting of nerves that control all of
the ______________________ muscles, organs, and glands sensory pathway nerves coming
from the sensory organs to the CNS consisting of sensory neurons.
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____________________________________________ - part of the ANS that is
responsible for reacting to stressful events and bodily arousal.
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____________________________________________ - part of the ANS that restores the
body to normal functioning after arousal and is responsible for the day-to-day
functioning of the organs and glands.
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PSY 101 – Dr. V
The Endocrine Glands
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Endocrine glands - glands that secrete chemicals called hormones directly into the bloodstream.
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Hormones - chemicals released into the bloodstream by endocrine glands.
_____________________ - gland located in the brain that secretes human growth hormone and
influences all other hormone-secreting glands (also known as the ______________________).
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Remember: influenced by the hypothalamus
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Pineal gland - endocrine gland located near the base of the cerebrum that secretes melatonin,
which regulates _________________________________________________________________
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Thyroid gland - endocrine gland found in the neck that secretes thyroxin, which regulates
______________________________________________________________________________
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______________- endocrine gland that controls the levels of sugar in the blood by secreting
insulin and glucagons.
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Too little insulin = _________________
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Too much insulin = ____________________ (low blood sugar) – feel hungry all the time
Gonads - the sex glands that secrete hormones that regulate sexual development and behavior
as well as reproduction.
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Ovaries - the female gonads.
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Testes - the male gonads.
______________________ - endocrine glands located on top of each kidney that secrete over
30 different hormones to deal with stress, regulate salt intake, and provide a secondary source
of sex hormones affecting the sexual changes that occur during adolescence.
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_______________ – one of the most “important” adrenal hormones
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Released when the body experiences __________________________________
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