Transcript endocrine system

If I only had a brain – Wizard of Oz
Biological Bases of Behavior
“The brain is the last and
greatest biological frontier. It
is the most complex thing we
have yet discovered in the
universe.”
Hippocrates (400 BC)
“From the brain and only
the brain arise our
pleasures, joys, laughter
and jests,as well as our
sorrows, pains, grief and
tears.”
Biological Bases of Behavior
“It’s amazing to think that the
body feeds the brain sugar and
amino acids and what comes out
is poetry and piroettes.”
-Neuroscientist Robert Collins (1997)
“Decade of the Brain”
President George Bush
“…to enhance public awareness of
the benefits to be derived from brain
research…”
2013 B.R.A.I.N. Initiative ($110 mil)
1809 Phrenology:
Francis Gall
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Traits=bumps
Bump=more
brain tissue
Pseudoscience
Brain? Localization
of function—yes.
Cranial bumps?
Wrong.
Searching for
the biology of
“self”
Is our identity in the
heart? In the
brain? In the whole
body?
8
Physiological Psychology
 Study
of...
Brain & nervous system
– Their relation to psychological things….
Thought
Emotion
Behavior
Physiological Psychology

Biopsychology
–Broader field

Neuroscience
–Study of brain-behavior link
Clinical Neuroscience
Cognitive Neuroscience
Affective Neuroscience

Neuropsychology
–Assessment of brain functioning
Surveying the Chapter: Overview
What We Have in Mind
 Building blocks of the mind: neurons
and how they communicate
(neurotransmitters)
 Systems that build the mind: functions
of the parts of the nervous system
 Supporting player: the slowercommunicating endocrine system
(hormones)
 Star of the show: the brain and its
structures
Information-processing
Encode (translate)
2) Organize & integrate
3) Respond
4) Self-monitor
1)
Self-awareness
Meta-cognition
The Neuron
©2001 Prentice Hall
The Neuron
 Neuron
= a cell
specialized to receive, process,
and/or transmit a signal
 Nerve
= bundle of axons (from many
neurons)
Nerve: a bundle of axons
The Neuron (a single cell)
3 Types Neurons

Sensory neurons
sense receptors --> CNS

Motor neurons
CNS --> muscles and glands

Interneurons
sensory --> interneurons-->motor
Spinal Reflex:
Pain Withdrawal
The Neural Impulse:
Electrochemical Beginnings

Hodgkin & Huxley (1952) - giant
squid

Fluids inside and outside neuron

Electrically charged particles
(ions)

Neuron at rest – negative charge
on inside compared to outside

-70 millivolts – resting potential
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RECEIVE
The Neuron
Dendrites
SOMA
SEND
Terminal
Buttons
AXON
Copyright 2002 Allyn & Bacon
Neurons and Neuronal Communication:
The Structure of a Neuron
There are billions of neurons
(nerve cells) throughout the body.
The Neural Impulse
Neural impulse
Brief electric surge that carries
the neuron’s message
Ions
Charged particles that move through
the cell membrane
“Resting Potential”

ions (+sodium atoms, -chloride
atoms, +potassium atoms)

ion channels along cell membrane

semi-permeable membrane
 membrane

has a sodium pump
Resting= -70 millivolts
flashlight battery)
(1/20 of
The Action Potential
 the
firing of a single neuron
 ion channels fly open
 rapid cascade of voltage change
runs down membrane
 all-or-nothing phenomenon
Action potential:
a neural impulse that travels down an
axon like a wave
Just as “the wave” can flow to
the right in a stadium even
though the people only move
up and down, a wave moves
down an axon although it is
only made up of ion exchanges
moving in and out.
All-or-none law
Size of action potential not
affected by increases
in stimulation beyond
threshold
Action Potential
Action Potential
When does the cell send
the action potential?...
when it reaches a
threshold
The neuron
receives
signals from
other
neurons;
some are
telling it to
fire and some
are telling it
not to fire.
 When the
threshold is
reached, the
action potential
starts moving.
 Like a gun, it
either fires or it
doesn’t; more
stimulation does
nothing.
 This is known as
the “all-ornone” response.
The threshold is reached when
excitatory (“Fire!”) signals
outweigh the inhibitory (“Don’t
fire!”) signals by a certain amount.
How neurons communicate
(with each other):
The action
potential
travels down
the axon
from the cell
body to the
terminal
branches.
The signal is
transmitted
to another
cell.
However, the
message
must find a
way to cross
a gap
between
cells. This
gap is also
called the
synapse.
Synaptic
Transmission
©2001 Prentice Hall
Synaptic Transmission
 Synapse
the synapse
to synapse
(noun)
(can be verb too)
 Neurotransmitters
Chemical messengers across
the synaptic cleft
The Synapse
The synapse is a
junction between the
axon tip of the
sending neuron and
the dendrite or cell
body of the receiving
neuron.
The synapse is
also known as the
“synaptic
junction” or
“synaptic gap.”
Synapse
Neurotransmitters
Neurotransmitters
are chemicals
used to send a
signal across the
synaptic gap.
Hearing the message
How Neurotransmitters Activate
Receptors
When the
key fits,
the site is
opened.
Reuptake:
Recycling Neurotransmitters [NTs]
Reuptake:
After the neurotransmitters
stimulate the receptors on
the receiving neuron, the
chemicals are taken back up
into the sending neuron to
be used again.
Keys that almost fit:
Agonist and Antagonist Molecules
An agonist molecule fills
the receptor site and
activates it, acting like the
neurotransmitter.
An antagonist molecule
fills the lock so that the
neurotransmitter cannot
get in and activate the
receptor site.
5 Stages of Synaptic Transmission
1. Synthesis
2. Release
3. Binding
4. Deactivation
5. Reuptake
Synapse
Hearing the message
How Neurotransmitters Activate
Receptors
When the
key fits,
the site is
opened.
Neurotransmitters
Acetylcholine
Glutamate
GABA
Dopamine
Norepinephrine
Serotonin
Endorphins
Roles of Different Neurotransmitters
Some Neurotransmitters and Their Functions
Neurotransmitter Function
Problems Caused by Imbalances
Serotonin
Affects mood, hunger,
sleep, and arousal
Undersupply linked to depression;
some antidepressant drugs raise
serotonin levels
Dopamine
Influences movement,
learning, attention, and
emotion
Oversupply linked to schizophrenia;
undersupply linked to tremors and
decreased mobility in Parkinson’s
disease and ADHD
Acetylcholine
(ACh)
Enables muscle action,
learning, and memory
ACh-producing neurons deteriorate as
Alzheimer’s disease progresses
Norepinephrine
Helps control alertness
and arousal
Undersupply can depress mood and
cause ADHD-like attention problems
GABA (gammaaminobutyric acid
A major inhibitory
neurotransmitter
Undersupply linked to seizures,
tremors, and insomnia
Glutamate
A major excitatory
neurotransmitter;
involved in memory
Oversupply can overstimulate the brain,
producing migraines or seizures; this is
why some people avoid MSG
(monosodium glutamate) in food
Keys that almost fit:
Agonist and Antagonist Molecules
An agonist molecule fills
the receptor site and
activates it, acting like the
neurotransmitter.
An antagonist molecule
fills the lock so that the
neurotransmitter cannot
get in and activate the
receptor site.
MDMA (Ecstacy)

Binds to serotonin transporters
 Increases serotonin
 Modulates release of dopamine
and norepinephrin
 Modulates release of oxytocin and
vassopressin (love)
 Causes high levels of serotonin,
dopamine, and norepinephrin
MDMA: Is it safe?
Controversial finding
1990s research by John
Hopkins U
Scary results:
A leading scientific journal yesterday retracted a paper it
published last year saying that one night's typical dose of
the drug Ecstasy might cause permanent brain damage.
The monkeys and baboons in the study were not
injected with Ecstasy but with a powerful
amphetamine, said the journal, Science magazine.
2014 Review
CONCLUSION
“…Deficits have been demonstrated in retrospective
memory, prospective memory, higher cognition, complex
visual processing, sleep architecture, sleep apnea, pain,
neurohormonal activity, and psychiatric status.
Neuroimaging studies have shown serotonergic deficits,
which are associated with lifetime Ecstasy /MDMA usage,
and degree of neurocognitive impairment. Basic
psychological skills remain intact. Ecstasy/MDMA use by
pregnant mothers leads to psychomotor impairments in
the children. Hence, the damaging effects of Ecstasy/MDMA
were far more widespread than was realized a few years ago.
In summary, MDMA can induce a wide range of
neuropsychobiological changes, many of which are
damaging to humans.
Roles of Different Neurotransmitters
Some Neurotransmitters and Their Functions
Neurotransmitter Function
Problems Caused by Imbalances
Serotonin
Affects mood, hunger,
sleep, and arousal
Undersupply linked to depression;
some antidepressant drugs raise
serotonin levels
Dopamine
Influences movement,
learning, attention, and
emotion
Oversupply linked to schizophrenia;
undersupply linked to tremors and
decreased mobility in Parkinson’s
disease and ADHD
Acetylcholine
(ACh)
Enables muscle action,
learning, and memory
ACh-producing neurons deteriorate as
Alzheimer’s disease progresses
Norepinephrine
Helps control alertness
and arousal
Undersupply can depress mood and
cause ADHD-like attention problems
GABA (gammaaminobutyric acid
A major inhibitory
neurotransmitter
Undersupply linked to seizures,
tremors, and insomnia
Glutamate
A major excitatory
neurotransmitter;
involved in memory
Oversupply can overstimulate the brain,
producing migraines or seizures; this is
why some people avoid MSG
(monosodium glutamate) in food
Serotonin
pathways
Networks of neurons that
communicate with serotonin
help regulate mood.
Dopamine
pathways
Networks of neurons that
communicate with dopamine are
involved in focusing attention
and controlling movement.
Receptor Binding Affinities for LSD
Serotonin
Dopamine
Norepinephrin
The Inner and Outer Parts of the
Nervous System
The central
nervous
system
[CNS]
consists of
the brain
and spinal
cord.
The CNS
makes
decisions
for the
body.
The
peripheral
nervous
system [PNS]
consists of
‘the rest’ of
the nervous
system.
The PNS
gathers and
sends
information
to and from
the rest of
the body.
The “Nerves”
are not the same as neurons.
Nerves consist of
neural “cables”
containing many
axons.
Nerves are part of
the peripheral
nervous system and
connect muscles,
glands, and sense
organs to the
central nervous
system.
More Parts of the Nervous System
The Peripheral Nervous System
The
Autonomic
Nervous
System:
The sympathetic
NS arouses
(fight-or-flight)
The
parasympathetic
NS calms
(rest and digest)
The Central Nervous System
 The brain is a web of
neural networks.
 The spinal cord is full of
interneurons that
sometimes have a “mind
of their own.”
Endocrine System
Network of glands
Chemical messangers..
Hormones
 Metabolism: HUNGER, THIRST
 Growth hormone
 Motivation: SEX, AGGRESSION
 Stress reactions: FIGHT OR FLIGHT
The Endocrine System
The endocrine system
refers to a set of glands
that produce chemical
messengers called
hormones.
The Body’s “Slow but Sure”
Endocrine Message System
 bloodstream
instead of synapses.
 molecules as
messages
 Molecules, called
hormones
 produced in glands
around body.
 messages go to the
brain and other
body tissues.
Adrenal Glands
1. The sympathetic “fight or
flight” nervous system
Adrenal Glands
2. Responds to stress by
sending message to
adrenal glands
3. Release stress hormones
Pancreas
Effect?  heart rate,  blood
pressure,  blood sugar.
ENERGY fight or flight!
Adrenaline
(Epinephrine)
Noradrenaline (Norepinephrine)
Cortisol
The Pituitary Gland
 master gland” of the
endocrine system.
 Controlled by hypothalamus
 Secretes hormones that regulate
other glands
 Growth Hormone (especially
during sleep)
 Oxytocin
“bonding” hormone
Pituitary gland
Endocrine System