Neuroscience Flashcards
What are neurons?
Cells in the nervous system that communicate with one another to perform information processing tasks
What are the three main parts of a neuron?
Dendrites, cell body, axon
What is another name for the cell body?
Soma
What is the function of the cell body?
To coordinate the information-processing tasks and keep the cell alive
What does the cell body contain?
Nucleus
What is the function of dendrites?
To receive information from other neurons and relay it to the cell body
What is the function of the axon?
To transmit information to other neurons, muscles or glands
What is the axon covered by?
Myelin sheath
What is the function of the myelin sheath?
To insulate the axon, thereby increasing efficiency of signal transmission
What is the myelin sheath made of?
Glial cells
What are glial cells?
Cells that support the functionality of neurons
How do glial cells support functionality of neurons?
Provide physical support, supply nutrients and enhance neuronal communication
What is a synapse?
Junction or region between axon of one neuron and dendrites/cell body of another
How many synapses is an adult thought to have?
Between 100 and 500 trillion
What type of signal is transmitted across a synapse?
Chemical
What are the three types of neuron?
Sensory, motor, interneuron
What is the function of a sensory neuron?
To receive information from the external world and convey it to the brain via the spinal cord
What is the function of a motor neuron?
To carry signals from the spinal cord to the muscles to produce movement
What is the function of an interneuron?
To connect sensory neurons, motor neurons, or other interneurons
What are three types of neuron structure?
Purkinje, Pyramidal, Bipolar
What is significant about Purkinje neurons?
Elaborate tree-like assemblage of dendrites
Example of Purkinje neuron
Purkinje cells of cerebellum
What is significant about Pyramidal neurons?
Triangular cell body and a single, long dendrite with many smaller dendrites
Example of Pyramidal neuron
Hippocampal pyramidal cell
What is significant about Bipolar neurons?
A few dendrites and a single axon
What type of signal is transmitted along a neuron?
Electrical
In what direction does the electrical signal travel along the neuron?
Dendrite - cell body - axon
What is resting potential?
The difference in electric charge between the inside and outside of a neuron’s cell membrane
What causes resting potential?
K+ ion concentration
What is action potential?
An electric signal/impulse that is conducted along the length of a neuron’s axon to the synapse
What causes action potential?
Opening of sodium channels and closing of potassium channels, allowing Na+ ions to flow inside the axon
What happens when action potential reaches its maximum?
Sodium channels close and potassium channels open, returning neuron to resting potential
What are breaks in the myelin sheath called?
Nodes of Ranvier
What happens to the electric signal when it passes along a myelinated axon?
Salatory conduction
What is salatory conduction?
Electrical impulse jumps from node to node
What is the benefit of salatory conduction?
Increases speed of conduction
What is the refractory period?
The time following an action potential during which a new action potential cannot be initiated
What does the action potential trigger?
Release of neurotransmitters
What does the release of neurotransmitters initiate?
Transmission of signal across synapse
Where are neurotransmitters released from?
Terminal buttons
What are terminal buttons?
Knoblike structures that branch out from an axon
What are neurotransmitters?
Chemicals that transmit information across the synapse to a receiving neuron’s dendrites
What do the dendrites of a receiving neuron contain?
Receptors
What are receptors?
Parts of the cell membrane that receive neurotransmitters and initiate a new electric signal
What is significant about receptors?
They are specific to a particular neurotransmitter - they fit like a lock and key
What are three ways neurotransmitters leave the synapse after transmission?
Reuptake by presynaptic cell, destroyed by enzymes or bind to autoreceptors
Where are autoreceptors located?
Presynaptic cell
What is the function of autoreceptors?
Feedback inhibition of neurotransmitter release
What are 7 neurotransmitters?
Acetylcholine, Dopamine, Glutamate, GABA, Noradrenaline, Serotonin, Endorphins
What is a mneumonic to remember the 7 neurotransmitters?
AceDoGluGaNoSE
What is Acetylcholine involved in?
Motor control
What is Dopamine involved in?
Movement, motivation, emotional pleasure and arousal
What is Glutamate involved in?
Learning and memory
What is GABA?
Primary inhibitory neurotransmitter
What is Noradrenaline involved in?
Control of mood and arousal
What is Serotonin involved in?
Regulation of hunger, sleep, arousal and aggressive behaviour
What are Endorphins involved in?
Pain pathways and emotion centres of brain
What is the name for cells in the nervous system that communicate with each other to perform information-processing tasks?
Neurons
Which type of neurons carry signals out to voluntary muscles in order for them to contract or expand?
Motor neurons
What is the difference in electrical charge between the inside and the outside of a neuron’s cell membrane called?
Resting potential
At rest, there is a higher concentration of which ion inside the cell membrane of the neuron?
K+ (Potassium)
At rest, there is a higher concentration of which ion outside the cell membrane of the neuron?
Na+ (Sodium)
What does the end of a neuron contain?
Many vesicles
What do vesicles at the end of neurons contain?
Neurotransmitters
What neurotransmitter is most closely associated with pleasure and motivation?
Dopamine (due to “reward circuit”)
What is the primary excitatory neurotransmitter in the brain?
Glutamate
What is the primary inhibitory neurotransmitter in the brain?
GABA
Both glutamate and GABA are which type of neurotransmitters?
Amino acid neurotransmitters
What is the CNS made up of?
Brain and spinal cord
What subdivision of the autonomic nervous system would be most associated with the phrase “fight or flight”?
The sympathetic nervous system
What part of the brain is dubbed as the brain’s “relay station”?
Thalamus
What does the thalamus do?
Sends sensory information to be processed in other regions of the brain - particularly the cerebral cortex
What part of the brain attaches significance to previously neutral events that are associated with fear, punishment or reward?
Amygdala
What are the smooth raised surfaces of the cerebral cortex called?
Gyri
What are the indentations or fissures of the cerebral cortex called?
Sulci
Which part of the brain helps to provide sense and meaning to information registered in the cortex?
Association areas
Which part of the brain shows a great deal of plasticity to learning and memory, particularly relative to spatial navigation?
Hippocampus
London taxi drivers may have an overdeveloped what due to plasticity?
Hippocampus
The “phantom limb syndrome” can be explained by brain plasticity in which region of the cortex?
Somatosensory cortex
What are chromosomes?
Strands of DNA wound around each other in a double-helix configuration
What extra chromosome from the father determines maleness?
Y chromosome
What is severed in the split-brain procedure?
Corpus collosum
What was the medical purpose of the split-brain procedure?
Reduce seizure activity
What are two functional neuroimaging techniques?
PET and fMRI
What was the name of the man who had an iron rod in his frontal lobe?
Phineas Gage
What was the significance of Phineas Gage?
Gave scientists the first clues into the role of the frontal lobes in emotion and personality
