i nteractive p resentation s lides f or i ntroductory p sychology
TRANSCRIPT
Table of ContentsBiological Psychology
The Action Potential
Anatomy of the Synapse
Types of Neurotransmitters
The Nervous System
The Endocrine System
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Fact or Falsehood?
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Neural impulses travel through the human body at the same speed that electricity travels through a wire.
Endorphins are neurotransmitter molecules similar to morphine.
For you to be able to run, your central nervous system must “talk” to your leg muscles.
The simplest neural pathways are those that govern our sexual drives.
The knee-jerk reflex requires the activity of the central nervous system.
Biological Psychology
Everything psychological—every idea, every mood, every urge—is simultaneously biological.
Everything psychological—every idea, every mood, every urge—is simultaneously biological.
is the scientific study of links between biological and psychological processes.
behavioral neuroscientists
neuropsychologists behavior geneticists physiological
psychologists biopsychologists
There are many kinds of biological psychologists, including:
Cell body (soma) – nucleus with chromosomes Dendrites – receive information from other neurons Axon – transmits information to other neurons, muscles,
and glands
The Neuron
Junction between one neuron’s axon and another’s dendrites/cell body
Neurotransmitters cross the synapse Plays a fundamental role in the communication between
neurons
The Synapse
Insulating layer of fatty material
Composed of glial cells
Helps efficient transmission of signals to other cells
Gaps in myelin sheath are nodes of Ranvier
Myelin
Video:Signal Transmission
Video:Signal Transmission
The Action Potential Electrical charge gathered by dendrites and cell body Electrical charge travels down the axon to synapse Stimulates the release of neurotransmitters into synapse Occurs only when electrical signal is at a certain level
(threshold) “All-or-none”—electrical impulse is the same no matter how
much stimulation the neuron receives Neuron returns to resting state after electrical charge is
transmitted
High concentration of K+ inside neuron
Lower concentration of K+ outside neuron
Higher concentration of Na+ outside neuron
K+ channels in cell membrane open in resting state
K+ moves out of neuron, leaving a -70 mv charge
The Resting Potential
Animation: Ion Flow: Part 1
Animation: Ion Flow: Part 1
The electrical charge reaches a threshold
K+ channels close Na+ channels open Na+ flows into the
neuron + charge inside the
neuron increases Charge inside the
neuron is +40 millivolts
The Action Potential is Initiated
Animation: Ion Flow: Part 2
Animation: Ion Flow: Part 2
Intracellular fluid is positively charged (+40 millivolts)
Adjacent Na+ channels open
The action potential travels down the axon membrane
K+ channels open K+ moves out of the cell Intracellular fluid becomes
negative again K+ channels close
The Action Potential Travels Down the Axon
Animation: Ion Flow: Part 3
Animation: Ion Flow: Part 3
Na+ and K+ channels close
Na+ concentration is higher inside the cell
K+ concentration is lower inside the cell
Na+/K+ pump restores resting state charge
Na+/K+ Pump Restores Ion Balance
Animation:Ion Flow: Part 4
.mov
Animation:Ion Flow: Part 4
.mov
The time following an action potential
Another action potential can’t occur during the refractory period
After the action potential reaches +40 mv, membrane channels return to original state
The neuron can now generate another action potential
The Refractory Period
Excitatory Messages
Inhibitory Messages
Animation:Signal Transmission
Animation:Signal Transmission
Animation:Signal Transmission
Animation:Signal Transmission
Presynaptic neuron’s axons end in terminal buttons
Terminal buttons contain synaptic vesicles
Synaptic vesicles contain neurotransmitters
Neurotransmitters are chemicals that transmit information across the synaptic gap (cleft)
Postsynaptic neuron’s dendrites contain receptor sites
Receptor sites fit certain neurotransmitters
Neurotransmitters bind to specific receptor sites in a lock-and-key system
Anatomy of the Synapse
Synaptic Transmission
What happens to the neurotransmitters in the synapse? synact_part2_SB.mov
Animation:Synaptic Transmission: Part 2
synact_part2_SB.mov
Animation:Synaptic Transmission: Part 2
Animation:Synaptic Transmission: Part 1
Animation:Synaptic Transmission: Part 1
Reuptake—Neurotransmitters are absorbed back into the presynaptic neuron
Enzyme Deactivation (Disassembly)—Neurotransmitters are broken down by enzymes in the synapse
Autoreceptors—Neurotransmitters bind to autoreceptor sites on the presynaptic neuron
Neurotransmitters passively drift out of the synaptic gap
What happens to neurotransmitters in the synapse?
Acetylcholine (ACh)
Dopamine
Serotonin
Norepinephrine
Endorphins
Enables muscle action, learning
and memory
With Alzheimer’s, ACh producing neurons
deteriorate
Influences movement, learning, attention and
emotion
High levels linked to schizophrenia, low levels
linked to Parkinson’s disease
Affects mood, hunger, sleep arousal
Low levels linked to depression
Helps control alertness and arousal
Low levels depress mood
Boosts mood, lessens pain
Artificial opiates cause brain to stop
producing endorphins
Functions Malfunctions
Types of Neurotransmitters
Connects the central nervous system to the body’s organs and muscles
Autonomic nervous system (ANS) Somatic nervous system (skeletal nervous system)
Peripheral Nervous System (PNS)