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Biopsychology
What makes you, you?
What makes you unique from every other person?
The Mind is what the Brain does
• Specific areas of the brain and specific systems in the body are responsible for– Learning and Memory– Sensing and perceiving – Emotion– Personality– Planning– Attention and arousal– Motivation– Etc.
The building blocks of the brain
The Neuron
The Neuron
• Types of Neurons– Sensory neurons (carry messages from
sense receptors towards the CNS)
– Motor neurons (carry messages from CNS toward muscles and glands)
– Interneurons (carry messages between nerve cells)
The Structure of a Neuron
Neural Communication• Two states
– Resting Potential Negatively charged ions on inside; positively
charged ions on outside; cell is negatively charged on inside relative to outside
– Action Potential Based on summation of excitatory and inhibitory
signals Cell depolarizes; i.e., cell becomes positively charged Voltage change (electrical surge) travels down axon
and causes release of neurotransmitter into the synapse
Neural Communication
• All or None Law– Neurons either fire or they don’t– Require a minimum amount of excitation or
stimulation in order to fire– Once the minimum threshold has been
reached, the neuron will fire
– Regardless of the intensity of stimulation, the neuron will fire with the same intensity
Neural Communication
• If neurons always fire with the same intensity, how do we discriminate intensity of the stimulus?
– The # of neurons stimulated by a single stimulus
– Rate of firing (up to a maximum)
Neural Communication
• Once the neuron fires, it releases its Neurotransmitter into the synapse– Neurotransmitter Chemical messengers that relay
neural messages across the synapse
• Neurotransmitter fits in receptor like a key fits in a lock
• Neurotransmitter either excites or inhibits the post-synaptic cell by binding to its receptors
Neuron Demonstration
Neural Communication
• Methods to stop neural transmission
– Reuptake
– Degradation
– Presynaptic autoreceptors
Seven Important Neurotransmitters
DopamineDopamine
SerotoninSerotonin
AcetylcholineAcetylcholine
GlutamineGlutamine
NorepinephrineNorepinephrine
GABAGABA
EndorphinsEndorphins
DopamineDopamine
Serotonin
Acetylcholine
Glutamine
Norepinephrine
GABA
Endorphins
Normal FunctionNormal Function::
Produces sensations of Produces sensations of pleasure and reward; used pleasure and reward; used
by CNS neurons in by CNS neurons in voluntary movementvoluntary movement
Problems with Imbalance:Problems with Imbalance:
Schizophrenia, Parkinson’s Schizophrenia, Parkinson’s diseasedisease
Substances that Affect:Substances that Affect:
Cocaine, amphetamines, Cocaine, amphetamines, Ritalin, alcoholRitalin, alcohol
Dopamine
SerotoninSerotonin
Acetylcholine
Glutamine
Norepinephrine
GABA
Endorphins
Normal Function:Normal Function:
Regulates sleep and Regulates sleep and dreaming, mood, pain, dreaming, mood, pain,
aggression, appetite and aggression, appetite and sexual behaviorsexual behavior
Problems with Imbalance:Problems with Imbalance:
Depression, certain anxiety Depression, certain anxiety disorders, obsessive-disorders, obsessive-compulsive disordercompulsive disorder
Substances that Affect:Substances that Affect:
Prozac, hallucinogenics Prozac, hallucinogenics (e.g. LSD)(e.g. LSD)
Dopamine
Serotonin
Acetylcholine
Glutamine
NorepinephrineNorepinephrine
GABA
Endorphins
Normal Function:Normal Function:
Controls heart rate, sleep, Controls heart rate, sleep, sexual responsiveness, sexual responsiveness,
stress, vigilance and stress, vigilance and appetiteappetite
Problems with Imbalance:Problems with Imbalance:
High blood pressure, High blood pressure, depressiondepression
Substances that Affect:Substances that Affect:
Tricyclic antidepressants, Tricyclic antidepressants, beta blockersbeta blockers
Dopamine
Serotonin
Acetylcholine
Glutamine
Norepinephrine
GABA
EndorphinsEndorphins
Normal Function:Normal Function:
Pleasurable sensations and Pleasurable sensations and control of paincontrol of pain
Problems with Imbalance:Problems with Imbalance:
Lowered levels resulting Lowered levels resulting from opiate addictionfrom opiate addiction
Substances that Affect:Substances that Affect:
Opiates: opium, heroin, Opiates: opium, heroin, morphine, methadonemorphine, methadone
Plasticity
• Plasticity –
– Ability of the nervous system to adapt or change as the result of experience; sometimes helps the nervous system adapt to physical damage
The Organization of the Nervous System
Nervous systemNervous system
Peripheral nervous Peripheral nervous systemsystem
Central nervous Central nervous system (CNS)system (CNS)
AutonomicAutonomicnervous systemnervous system
SomaticSomaticnervous systemnervous system
SympatheticSympatheticnervous systemnervous system
Parasympathetic Parasympathetic nervous systemnervous system
Divisions of the Nervous System
• Central Nervous System (CNS)–Brain and spinal cord
• Peripheral Nervous System (PNS)–Connects brain and spinal cord with
the rest of the body
Peripheral Nervous System
• Somatic Nervous System– Carries incoming messages from sense organs
– Carries outgoing messages to skeletal muscles; mobilizes voluntary movements
• Autonomic Nervous System– Carries signals from the CNS to the internal
organs
– regulates involuntary functions such as digestion, respiration, heart rate
Autonomic Nervous System
• Sympathetic Division– Mobilized under stress – (e.g., controls 4 F’s)
• Increases heart rate and respiration, increases muscle tension, shuts off digestion
• Parasympathetic Division– Responsible for basic processes or
homeostasis• Slows heart rate and respiration, increases
digestive functioning
Example• Hear rattlesnake
– Somatic NS orients eyes to sound to locate snake
– Sympathetic Division of ANS mobilizes fight or flight response (i.e., blood to skeletal muscles; increases respiration)
– Somatic NS initiates skeletal muscles to escape
– Once escaped, Parasympathetic NS initiates relaxation response
The Endocrine System(the body’s chemical messenger system)
The Endocrine System
• Pituitary gland– Master gland; i.e., produces
hormones that influence the secretions of all other endocrine glands
– Attached to and controlled by hypothalamus
The Endocrine System
• Endocrine glands release hormones into bloodstream; circulate through body until target organ is reached
• Non-stress conditions supports parasympathetic nervous system in maintaining basic processes or homeostasis
• Stress conditions supports sympathetic nervous system through release of epinephrine (adrenaline)
Example Revisited• Hear rattlesnake
– Somatic NS orients eyes to sound– Sympathetic Division of ANS mobilizes fight or
flight response– Somatic NS initiates skeletal muscles to escape– Parasympathetic NS initiates return to resting
state, But, …
– Endocrine system release of adrenaline, explains why you feel edgy for a long time afterward
The Endocrine System
Glands Systems/ Processes regulated
Anterior Pituitary Ovaries and Testes, Milk production, metabolism, stress reactions
Posterior Pituitary Conservation of water, milk secretion, uterus contractions
Thyroid Metabolism, physical growth & development
Parathyroid Calcium levels
Pancreas Glucose (sugar) metabolism
Adrenal glands Fight or flight response, metabolism, sexual desire (especially women)
Ovaries Female sex characs., production of eggs
Testes Male sex characs., sperm production, sexual desire
How Does the Brain Produce Behavior and
Mental Processes?
The brain is composed of many specialized modules that work together to create
mind and behavior
Film on Structures of the Brain
Three Layers of the Brain• Brain stem and cerebellum
– Drive vital functions, such as heart rate, breathing, digestion
• Limbic system– Adds emotions, complex motives, increased
memory abilities
• Cerebrum– Enables reasoning, planning, creating,
problem solving
The Brain Stem and Cerebellum
• Thalamus
• Pons
• Cerebellum
• Medulla
• Brain stem
The Limbic System
• Hypothalamus –Serves as the brain’s blood-testing laboratory, constantly monitors blood to determine the condition of the body
The Limbic System
• Amygdala –Involved in memory and emotion, particularly fear and aggression
The Limbic System
• Hippocampus –Involved in establishing long-term memories
The Cerebrum
• Cerebrum –Topmost layer of the brain; the bulbous cap over the limbic system
• Cerebral cortex –Thin gray-matter covering of the cerebrum; carries on thinking and perceiving
• Cerebral hemispheres –The two walnut shaped halves of the cerebrum, connected by the corpus callosum
W. W
. No r
ton
Phineas Gage
Specialization of the Cerebral Hemispheres
Left Hemisphere Right Hemisphere• Spontaneous
speaking and writing
• Responses to complex commands
• Word recognition• Memory for words
and numbers• Sequences of
movements• Feelings of anxiety• Positive emotion
• Repetitive but not spontaneous speaking
• Responses to simple commands
• Facial recognition• Memory for shapes
and music• Spatial interpretation• Emotional
responsiveness• Negative emotion
Film on Split-Brain