Download Myers Update 2011

Myers PSYCHOLOGY
Seventh Edition in Modules
Module 3
Neural and Hormonal
Systems
James A. McCubbin, Ph.D.
Clemson University
Worth Publishers
“Everything
psychological is
simultaneously
biological.”
It all Starts with the Neuron
Neural and Hormonal Systems
Will Explain Why We FEEL……
Pain
Strong
Sick
Nervous
Neural
Communication
 Biological Psychology
 branch of psychology concerned with the links
between biology and behavior
 allows a better understanding of sleep and
dreams, depression and schizophrenia, hunger
and sex, stress and disease
 some biological psychologists call themselves
behavioral neuroscientists, neuropsychologists,
behavior geneticists, physiological
psychologists, or biopsychologists
Neural
Communication
 Neuron
 a nerve cell
 the basic building block of the nervous system
 Cell body (Soma)
 Contains the nucleus and other parts of the cell needed to
sustain life
 Dendrite
 the bushy, branching extensions of a neuron that receive
messages and conduct impulses toward the cell body
 Axon
 the extension of a neuron, ending in branching terminal fibers,
through which messages are sent to other neurons or to muscles
or glands
 Myelin [MY-uh-lin] Sheath
 a layer of fatty cells segmentally encasing the fibers of many
neurons
 enables vastly greater transmission speed of neutral impulses
Neural
Communication
Neural
Communication
 Action Potential
 a neural impulse; a brief electrical charge that travels
down an axon
 generated by the movement of positively charged
atoms in and out of channels in the axon’s membrane
 Threshold
 the level of stimulation required to trigger a neural
impulse
 Synapse [SIN-aps]
 junction between the axon tip of the sending neuron
and the dendrite or cell body of the receiving neuron
 tiny gap at this junction is called the synaptic gap or
cleft
Neural
Communication
How a neuron fires:
 electrochemical process- electricity travels from
dendrites to terminal branches
 when receives stimulation by pressure heat, or a
chemical message from a near by neuron, the neuron
fires an impulse called action potential
 dendrites receive messages from other cells
 axon passes the message away from the cell body to
other neurons or to muscle or glands
 myeline sheath helps speed up the impulse, if
degenerates, then the result is a slowing of all
communications
 at the end of the axon are terminal branches with
which form junctions with other cells
Neural Communication
Santiago Ramon y Cajal:
 described gaps between individual
nerve cells (synapse)
 Concluded that the individual neurons
must function as independent agents
with the nervous system
Neural
Communication
Action Potential
Neural Communication
 All-or-None Principle:
 a neuron either fires completely or not at all
 if the dendrites of a neuron receive enough
neurotransmitters to push the neuron past its
threshold, the neuron will fire completely
everytime
 think of a toilet, it either flushes or it
doesn’t
The All-or None Response
The idea that
either the
neuron fires or
it does not- no
part way firing.
Like a gun
Neural Communication
Toilet Example:
 all-or-none principle: the toilet either flushes completely
or not at all; it doesn’t flush a little or a lot
 direction of impulse: toilet only flushes one way, it can’t
come back the other direction
 refractory period: after you flush, it won’t flush again for
a certain period of time, even if you push the handle
repeatedly
 threshold: you can push the handle a little bit, but it wont
flush until you push the handle pas a certain critical point
 resting potential: a toilet with a tank represents resting
potential, the toilet is waiting to fire
 action potential: opening the flap in the tank and the
water
Neurotransmitters
 chemical messengers that traverse the synaptic
gaps between neurons
 when released by the sending neuron,
neurotransmitters travel across the synapse and
bind to receptor sites on the receiving neuron,
thereby influencing whether it will generate a
neural impulse
 Excitatory: they excite the next cell into firing
 Inhibitory: inhibit the next cell from firing
 reuptake: exess neuronstransmitters are
reabsorbed by the sending neuron
 bloodbrain barrier: enables the brain to fence
outward chemicals circulating the blood
Neural
Communication
Neural
Communication
Neural
Communication
Serotonin Pathways
Dopamine Pathways
Neural Communication
Dopamine
 lack of Dopamine is associated with Parkinson’s
disease
 disorder of the brain that leads to shaking (tremors) and
difficulty with walking, movement, and coordination
 too much Dopamine is associated with
Schizophrenia
 mental disorder that makes it difficult to tell the
difference between real and unreal experiences, to think
logically, to have normal emotional responses, and to
behave normally in social situations
Neural
Communication
 Acetylcholine
 a neurotransmitter that, among its
functions, triggers muscle contraction
 Endorphins [en-DOR-fins]
 “morphine within”
 natural, opiate-like neurotransmitters
 linked to pain control and to pleasure
Neural
Communication
Agonist and Antagonists
Neural Communication
Agonist Drugs
 drugs that mimic and produce the same
effects as certain neurotransmitters
 opiates (morphine, heroin) are agonists for
endorphoins
Antagonist Drugs
 blocks a neurotransmitter
https://www.youtube.com/watch?v=rxqHVoZ0fzc
Explain what is happening within
the:
•Sympathetic Nervous System
•Parasympathetic Nervous System
•Somatic Nervous System
•Autonomic Nervous System
The Nervous System
 Nervous System
 the body’s speedy, electrochemical
communication system
 consists of all the nerve cells of the peripheral
and central nervous systems
 Central Nervous System (CNS)
 the brain and spinal cord
 Peripheral Nervous System (PNS)
 the sensory and motor neurons that connect
the central nervous system (CNS) to the rest
of the body
The Nervous System
Nervous
system
Central
(brain and
spinal cord)
Peripheral
Autonomic (controls
self-regulated action of
internal organs and glands)
Skeletal (controls
voluntary movements of
skeletal muscles)
Sympathetic
(arousing)
Parasympathetic
(calming)
The Nervous System
 Nerves
 neural “cables” containing many axons
 part of the peripheral nervous system
 connect the central nervous system with
muscles, glands, and sense organs
 Sensory Neurons
 neurons that carry incoming information from
the sense receptors to the central nervous
system
The Nervous System
 Interneurons
 CNS neurons that internally communicate and
intervene between the sensory inputs and
motor outputs
 Motor Neurons
 carry outgoing information from the CNS to
muscles and glands
 Somatic Nervous System
 the division of the peripheral nervous system
that controls the body’s skeletal muscles
The Nervous System
 Autonomic Nervous System
 the part of the peripheral nervous system that
controls the glands and the muscles of the
internal organs (such as the heart)
 Sympathetic Nervous System
 division of the autonomic nervous system that
arouses the body, mobilizing its energy in
stressful situations
 fight or flight response
 Parasympathetic Nervous System
 division of the autonomic nervous system that
calms the body, conserving its energy
The Nervous System
 Reflex
 a simple, automatic, inborn response to a sensory stimulus
Information is carried from
the skin receptors along a
sensory neuron to the spinal
cord. From here it is passed
via interneuron's to motor
neurons that lead to muscles
in the hand and arm
Muscle
Skin
receptors
Brain
Sensory neuron
(incoming information)
Motor neuron
(outgoing
information)
Interneuron
Spinal cord
Because this reflex involves only
the spinal cord, the hand jerks
away from the candle before the
information has researched the
brain, causing the experience of
pain
The Nervous System
Neurons in the brain
connect with one
another to form networks
Inputs
The brain learns by modifying
certain connections in
response to feedback
 Neural Networks
 interconnected neural
cells
 with experience,
networks can learn, as
feedback strengthens
or inhibits connections
Outputs
that produce certain
results
 computer simulations
of neural networks
show analogous
learning
Neural Networks
 Stephen Kosslyn and Olivier
Koenig
 City analogy: Like people networking
with other people, neurons seek short, fast
connections
The Endocrine
System
 Endocrine System
 the body’s “slow”
chemical
communication
system
 a set of glands
that secrete
hormones into the
bloodstream
Neural and Hormonal
Systems
 Hormones
 chemical messengers, mostly those manufactured by the
endocrine glands, that are produced in one tissue and
affect another
 Adrenal [ah-DREEN-el] Glands
 a pair of endocrine glands just above the kidneys
 secrete the hormones epinephrine (adrenaline) and
norepinephrine (noradrenaline), which help to arouse the
body in times of stress
 Pituitary Gland
 under the influence of the hypothalamus, the pituitary
regulates growth and controls other endocrine glands