The Brain - Module 9 - Neurons & Neurotransmitters Flashcards
Phrenology
Study bumps on the skull
Localization of Function
The idea that various brain regions have particular functions
Biological Psychology
The scientific stud of the links between biological (genetic, neural, hormonal) and psychological processes
Neuron
A nerve cell, basic building block of nervous system
Dendrites
A neuron’s busy, branching extensions that receive messages and conduct impulses toward the cell body
Axon
The neuron extension that passes through its branches to other neurons or to muscles or glands
Myelin Sheath
A fatty tissue layer segmentally encasing the axons of some neurons, enables vastly greater transmission speed as neural impulses hop from one nod to the next
Multiple Sclerosis
Communication with muscles slows, with eventual loss of muscle control
Action Potential
A neural impulse, a brief electrical charge that travels down an axon
Ions
Electrically charged atoms
Resting Potential
Positive outside, negative inside
Selectively Permeable
Axon’s surface is very selective about what it allows through its gates
Refractory Period
A period of inactivity after a neuron has fired
Excitatory
Like pushing a neuron;s accelerator
Inhibitory
Like pushing a neuron’s brakes
Threshold
The level of stimulation required to trigger a neural impulse
All-or-None Response
A neuron’s reaction of either firing with a full-strength response or not firing at all
Synapse
The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
Synaptic Gap
Tiny gap between axon tip and dendrite
Neurotransmitters
Chemical messengers that cross the synaptic gaps between neurons, when released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron
Reuptake
A neurotransmitter’s re-absorption by the sending neuron
Acetylcholine (ACh)
Plays a role in learning and memory, messenger at every junction between motor neurons and skeletal muscles
ACh Released
Muscle contracts
ACh Blocked
Muscles can’t contract, we are paralyzed
Dopamine
Influences voluntary movement, learning, attention, reward and emotion
Serotonin
Affects mood, hunger, sleep and arousal
Nor epinephrine
Helps control alertness and arousal, mood and sleep
GABA (gamma-aminobutyric acid)
A major inhibitory neurotransmitter, blocks/inhibits certain brain signals and decrease activity in nervous system, relaxation and sleep
Glutamate
A major excitatory neurotransmitter, involved in memory and learning, sends signals between nerve cells
Endorphins
“Morphine within”, natural, oplate-like neurotransmitters links to pain control and pleasure
Agonist
A molecule that, by binding to a receptor site, stimulates a response
Antagonist
A molecule that, by binding to a receptor site, inhibits or blocks a response
