Transcript Powerpoint

Concepts of Neurobiology
Copyright all rights reserved Austin Community College
Introduction
The 1990’s was called the “decade of the
Brain” with the challenge of studying the
biological basis of behavior
 In keeping with the “neurobiology scientific
revolution”, greater emphasis is placed on the
organic basis of mental illness
 Research is ongoing and new discoveries are
being made.

What makes a brain happy and
healthy?
Balanced Neurotransmitters
 Brain uses the most glucose
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Healthy Diet (serotonin/GABA shake)
Aerobic exercise
Empathic conversation
8 hours of sleep
Listening to music
Being in nature
Hearing an inspiring speech
Helping others
What makes a brain happy?
But is not so healthy
Coke, potato chips, and chocolate
 A margarita
 Going shopping
 Driving fast
 Cocaine
 Nicotine
 Rollercoasters/action movies
 Gambling
 Computer Games

Thee Parts of the Brain
 1.
Forebrain
– A. Cerebrum
– B. Diencephalon
 2.
Midbrain
 3. Brain Stem
 1.
The Forebrain
– A. Cerebrum
Consists
of right and left hemisphere connected
by a deep groove called the corpus callosum.
Each hemisphere is divided into four lobes:
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Frontal lobes
Parietal lobes
Temporal lobes
Occipital lobes
The Lobes of the Cerebrum:
a closer Look

Frontal lobes
– The executive;
decision maker,
reliant on other parts
of the brain for data.
Prefrontal is the
personality

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Temporal Lobes
– Hearing
Parietal Lobes
– Perception,
interpertation touch
body perception
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Occipital Lobes
– Sight
Forebrain: Diencephalon

The diencephalon
connects the cerebrum
with the lower brain
structures
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Limbic System: “the
“emotional brain:”
Limbic system consists of
many structures
Contain “4 F’s”-Feeding,
fighting, fleeing and
fornicating
Memory, Pleasure
Pathway, emotions,
motivation
Forebrain: Diencephalon
(Limbic System)
 Connects
the cerebrum with the lower
brain structures
 Very powerful
 Do not underestimate
 Pleasure Emotions Cravings Memories
 Can overwhelm the Frontal Lobe
Other Important Structures in the
Limbic System
 Hippocampus-Contains
memory
 Amigdala-stores affect about memories,
ie, fear, anger, rage, love, and happiness
 Both structures are bilateral, under the
temporal lobe
 VTA is a pathway in this
area of the brain that is the
seat of craving in addiction
Basil Ganglia
 controls
starting and stopping
movements
– Balances excitatory (acetylcholine) and
inhibitory(dopamine) neurotransmitters in
extra-pyramidal system (EPS). GABA
inhibits also.
– If there are changes in the balance between
acetylcholine and dopamine motor
function will abnormal.
Cerebellum
Second largest structure
 Dependent on the balance between
acetylcholine and dopamine for normal
movement
 Function (highly specialized)
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Movement
Posture
Balance
Sensory motor coordination
Hand eye coordination
The Midbrain and Brian Stem
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The midbrain contorls visual, auditory, and balance (righting) reflexes.
Substantia Nigra Produces Dopamine in this area
Brain stem
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Pons: regulates respiration and muscle tone
Medulla: reg. heart rate, blood pressure,
Cerebellum: muscle tone and coordination
Reticular Activating System
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(not on test)
Responsible for
regulation of arousal
and sleep-wake
transitions.
Nerve Tissue
 Neurons
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Cell body, contains nucleus
Axon, transmits message to next cell
Dendrites, receives messages from cells
Myelin sheath: insulates and promotes conduction
 Three
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are composed of:
classes of neurons in CNS
Afferent: (sensory)
 Send messages to the brain
Efferent: (motor)
 Send messages away from the brain
Interneurons, in CNS
Neurons: a reveiw
Synapses
 The
synapse is the junction between
two neurons .
 Synaptic Cleft: space between neurons
 Pre-synaptic neuron: area of axon
where neurotransmitters are stored.
 Postsynaptic neuron: area of dendrite
where receptor sites are located.
Synapse: a review
Neurotransmitters
 Play
an important role in human
emotions and behavior
 Are the target for the mechanism of
action for psychotropic medications
 Summary: Neurotransmitters are
released into the synaptic cleft from the
axon to the dendrite. The substance is
either inactivated or returned to the
axon.
Categories of neurotransmitters
 Cholinergics
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Acetylcholine: involved in sleep, arousal,
movement, MEMORY,
 Monoamines
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Norepinephrine: effects mood, cognition,
perception, locomotion, CV functioning,
sleep and arousal
Monoamines:
 Dopamine:
effects movement,
coordination, emotions, voluntary
judgment, and release of prolactin
 Serotonin: effects sleep, arousal, libido,
appetite, mood, aggression, pain
perception, coordination, and judgment
 Histamine: Not sure of influence on
mood
Amino Acids and Neuropeptides
 Amino
Acid: gamma aminobutyric
acid(GABA) functions as an inhibitor
neurotransmitter. Has a calming effect.
 Neuropeptides: endorphins and
enkephlins, modulates pain and
reduces peristalsis. Also called “natural
opiates”
Autonomic Nervous System
 Sympathetic:
Dominates in stressful
situations, prepares body for fight or
flight
 Parasympathic: Dominates when
person is relaxed
Endocrine System:
a communication system
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Neurochemical Messengers called hormones:
Hypothalamus- instructs the pituitary gland
– The pituitary gland:

secretes TSH (Thyroid stimulation Hormone) stimulates target
cells in:
– The thyroid (energy level)
– The pituitary gland also stimulates target cells in the:
– The pituitary gland can monitors
The release ACTH (adrenal corticotropic
hormone) stimulates the adrenals
(response to stress cortisol)
 The gonads (testosterone and estrogen)

The Stress Response to Cortisol
Other factors in Neurobiology
 Genetics:
research has shown that all
major mental illness seem to have a
genetic base.
 Psychoimmunology: Normal immune
responses are decreased with grief,
bereavement, and depression.
Implications for Nursing
 Nature-Nurture:
Each effects the other.
 A nurse never “Just takes care of the
body” even if you want to.
 Mental health nurses can not “Just take
care of the mind.”
 “Pathophysiology” check lab work
daily. Listen and observe
Goals for the Student Nurse in
Mental Health Nursing
 Learn
about mental illness
 Improve communication
 Psychotropic Medication
 Decrease your fear of “Mental Patients”
 Attend groups
Neurobiology
The End