Transcript Unit Two: Biological Bases of Behavior

Unit Two:
Biological Bases of Behavior
AP Psychology
Ms. Egan
The Biology Behind the
Psychology
• “Everything Psychological is ultimately
Biological.”
– What does this say to you?
Neurons: building blocks
of the Nervous System
Neural Communication
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Action potential: a neural impulse
Threshold: minimum intensity needed to fire impulse
Neuron firings are all-or-none responses
Synapse: gap between neurons (also called a synaptic gap
or cleft)
• Neurotransmitters: chemical messengers that bind to
receptor sites on receiving neuron
• Reuptake: sending neuron reabsorbs excess
neurotransmitters
Demonstrations
Action Potential
Synaptic Transmission
Types of Neurons
• Sensory Neurons (afferent) ~ 2 million
– Sends messages from sense organs  brain
• Motor Neurons (efferent) ~ 2-3 million
– Sends messages from brain  muscles, organs, glands
• Interneurons ~ Billions & Billions
– Relay messages between sensory & motor neurons
• Glial cells – “The forgotten cell”
– Glue cells which help connections, insulate, and clean up
Influence of
Neurotransmitters
• Each neurotransmitter has a specific effect on behavior & emotions
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Acetylcholine:
muscle action, learning, memory
Dopamine:
movement, learning, attention, emotion
Serotonin:
mood, hunger, sleep, arousal
Norepinephrine:
alertness, arousal
GABA (gamma-aminobutyric acid):
inhibitory neurotransmitter
Glutamate:
excitatory neurotransmitter, memory
• Find a condition or disease associated with the blockage or increase
in one of these neurotransmitters.
Drugs &
Neurotransmitters
• Endorphins: natural “opiates” released in response
to pain or vigorous exercise
• Why not flood the brain with artificial opiates??
– Brain will stop producing natural ones
– Withdrawal symptoms
• Drugs affect communication at the synapse
– Agonist Molecule: excites, mimics neurotransmitter
– Antagonist Molecule: inhibits, blocks neurotransmitter
Neuron FAQ’s
• 100 Billion neurons in the human body
– It would take you 3,171 years to count all the
neurons (1 per second)
• 4-100 Microns wide (1 micron=1/1000th of a
millimeter)
• Your neurons are for life! You will have less and
less as you get older
The Nervous System
Neuron to
Central Nervous
neuron
System
communication
Brain & Spinal
Cord
Peripheral
Nervous System
(Links CNS with
muscles, glands,
sense receptors)
Somatic
Autonomic
(Skeletal)
(Internal Organs)
Sympathetic
(Arousing)
• Nerves: neural cables
containing many axon
Parasympathetic
(Calming)
Endocrine System
• Slower than nervous system
• Uses hormones (another chemical messenger) to
communicate
• Flow from tissues through bloodstream to other
tissues
• Adrenal glands: above kidneys; secrete hormones
to arouse body during stress
• Pituitary glands: controlled by hypothalamus,
regulates growth and controls endocrine glands
The Brain
How does our brain produce behavior and
mental processes?
What’s a brain good for
anyway?
• Case Study:
Phineas Gage
Case Study: Phineas Gage
• Which part of the brain did Gage injure?
• Why did Gage feel no pain after the
injury?
• What were the “treatments” given to
Gage after the injury?
• What was the major change in Gage after
the accident?
• What is localization of the brain?
Studying the Brain
• Electroencephalogram (EEG)
– Measures brains electrical waves by attaching
electrodes to the scalp
• Positron Emission Tomography (PET Scan)
– Injection of radioactive glucose (brain sugar) to
detect where fuel goes under different situations
• Magnetic Resonance Imaging (MRI)
– Magnet aligns spinning atoms of brain to show
tissue and brain anatomy
• Functioning MRI (fMRI)
– Shows brain function & bloodflow
Brain Structures
• Brain Map (BBC) OR 3-D Brain (PBS)
• Using the Brain Links, complete your brain
concept map. Give an example of how each
structure influences your behavior or emotions:
YOU SHOULD KNOW THE FOLLOWING!!!
Brainstem
Midbrain
Cerebral Cortex
Occipital Lobes
Limbic System
Pituitary Gland
Pons
Cerebrum
Parietal Lobes
Temporal Lobes
Amygdala
Hippocampus
Medulla Oblongata
Frontal Lobe
Thalamus
Cerebellum
Hypothalamus
Corpus Callosum
Split Brain
• Each brain hemisphere
serves a different
purpose
• Vogel & Bogen (1961)
– Stop seizures by
splitting corpus
collosum
– Sperry, Myers,
Gazzaniga were
successful with animals
– HE-ART
Split Brain Demo
Right vs. Left Brain
• We only use 10% of our brain
• Your brain does not grow new cells
• Some people are right-brained,
others left-brained
• Brain damage cannot be repaired