04. Nervous System Flashcards
To 'master' U3AoS1 - Nervous System
Adrenaline
(also known as epinephrine) a neurohormone that increases physiological arousal and contributes to the consolidation of emotionally arousing memories
Autonomic nervous system
branch of the PNS responsible for connecting the CNS and the body’s visceral (non-skeletal) organs, muscles and glands like the heart and liver
Axon
the long strand-like part of a neuron that transmits a message from one end of the neuron to the other
Axon terminals
the ends of a neuron that release a message into the synapse
Brain
CNS- the body’s information centre, responsible for initiating and processing actions, thoughts and behaviour
Central nervous system- components and function
**the brain and the spinal cord, responsible for transmitting neural messages to and receiving and processing neural messages from the PNS
Cerebellum
a brain structure which encodes and stores implicit procedural memories
Cerebral cortex/ Neocortex
an outer brain structure (outermost layer) where long-term memories are stored.
Dendrites
the bushy spines of a neuron that receive neurotransmitters
Dopamine
Remember: HAT
a neuromodulator primarily responsible for Hunger and eating, Addiction, Thirst and drinking
Excitatory effect
when a neurotransmitter causes the postsynaptic neuron to become more likely to fire an action potential
GABA
the primary inhibitory neurotransmitter- key role in reducing anxiety/stress response
Glutamate
the primary excitatory neurotransmitter- key roles in learning and memory
Inhibitory effect
when a neurotransmitter causes the postsynaptic neuron to become less likely to fire an action potential
Interneurons
CNS neurons (brain and spinal cord only) that transfer impulses between sensory and motor neurons as part of the reflex arc
Lock-and-key process
an analogy used to describe the role and functions of neurotransmitters and receptor sites in the process of neural transmission
Long-term depression
Long-lasting weakening of synaptic connections due to low frequency stimulation/activation of synaptic pathway.
Long-term potentiation
Long-lasting strengthening of synaptic connections due to high frequency stimulation/activation of synaptic pathway.
Motor neurons
neurons that transmit information (motor neural messages) about voluntary movement from the CNS to the PNS
Myelin
the fatty protein substance that surrounds and insulates the axon of a neuron
Neural plasticity
the ability of the brain to physically change in response to experience
Neural reception
the process in which a neuron accepts, or receives, a message
Neural transmission
the process in which a neuron sends a message
Neurochemical
a chemical substance that transmits neural information within the nervous system
Neurohormone
a chemical substance sent from neurons into the bloodstream
Neuron
a nerve cell responsible for transmitting, receiving and processing information
Neuromodulator
a chemical molecule that has an effect on multiple postsynaptic neurons
Neurotransmitter
a chemical substance that carries information between neurons
Parasympathetic nervous system
a branch of the ANS responsible for returning and maintaining the body’s visceral organs, muscles and glands at optimal and balanced functioning
Peripheral nervous system
all nerves outside the CNS, responsible for transmitting information to and from the CNS
Postsynaptic neuron
the neuron that receives a message from the synapse
Presynaptic neuron
the neuron that releases a message into the synapse
Pruning
the elimination of synaptic connections that are not adequately activated
Receptor sites
protein molecules located on the dendrites of a postsynaptic neuron, responsible for receiving neurotransmitters
Rerouting
the ability of a neuron that is connected to a damaged neuron to create an alternative synaptic connection with an undamaged neuron
Sensory neurons
neurons that transmit information (sensory neural messages) about the body’s sensations from the PNS to the CNS
Sensory receptor
a nerve ending that detects sensations in the environment and body
Sensory stimuli
anything in the environment or body that is detected by the body’s senses
Serotonin
Remember: SAM
neuromodulator primarily responsible for Sleep, Aggression and impulsivity, and Mood
Skeletal muscles
muscles connected to the skeleton that are involved in conscious, voluntary movement- link to SOMATIC NS
Somatic nervous system
the branch of the PNS responsible for sending motor information from the CNS to the body’s skeletal muscle, and bringing sensory information from the body to the CNS in order to formulate voluntary responses
Spinal cord
a long cable of nerve tissue (neurons) connecting the brain to the peripheral nervous system, responsible for sending motor information from the brain, and sensory information from the body
Spinal reflex
an unconscious response to sensory stimuli that is initiated at the spinal cord, not involving the brain
Spinal sensory-motor circuit (reflex arc)
the path that neural messages take as part of the spinal reflex response, involving sensory messages to the spinal cord which are immediately relayed from the spinal cord as motor messages
Sprouting
the ability of dendrites or axons to develop new extensions or branches
Sympathetic nervous system
a branch of the ANS responsible for activating the body?s visceral organs, muscles, and glands for increased activity or when under threat
Synapse
the area in which neuronal transmission occurs between two neurons, including the sending end of the presynaptic neuron, the gap between two neurons, and receiving end of the postsynaptic neuron
Synaptic gap
the space in between two neurons into which a message is sent
Synaptic buttons
(also known as synaptic knobs, terminal buttons) the end of the presynaptic neuron?s axon terminals that release neurotransmitters
Synaptic plasticity
a type of neural plasticity that refers to the ability of synaptic connections to form, weaken or strengthen in response to activity and experience
Visceral muscles (organs or glands)
the body?s non-skeletal muscles, organs and glands that are largely self-regulating and don’t require conscious control. These are controlled by the ANS
Afferent
conducting or conducted inwards or towards something
Conscious response
a reaction to a sensory stimulus that involves awareness; usually **voluntary, goal-directed **and with some degree of control over it
Efferent
conducted or conducting outwards or away from something
Neural pathway
a route based on interconnected neurons that form a communication network within the brain and between the brain and other parts of the nervous system and body
Changes to synapse after LTD
As a result of LTD, less neurotransmitter (i.e., Glutamate) will be released from the pre-synaptic neuron, and there will be a reduction in the number of receptor sites on the post-synaptic neuron (reduction of dendritic spines).
Changes to synapse after LTP
As a result of LTP, more neurotransmitter (i.e., Glutamate) will be released from the pre-synaptic neuron, and there will be an increase in the number of receptor sites on the post-synaptic neuron (increased sprouting of dendritic spines).The post-synaptic neurons become more and more responsive to the pre-synaptic neurons.
Unconscious response
a** reaction to a sensory stimulus** that does not involve awareness; involuntary, unintentional, automatic and we cannot ordinarily control its occurrence
Enteric Nervous System
a sub-division of the autonomic nervous system embedded within the walls of the gastrointestinal (digestive) tract and dedicated to its functioning
Vagus Nerve
a peripheral nerve which connects the brain (in CNS) with key structures including the heart and the GI tract- pathway for brain to enteric NS and vice versa
Synaptogenesis
formation of additional synapses where the dendritic spines (post-synaptic neuron) and filigree appendages (pre-synaptic neuron) meet
Filigree appendages
**Axon ‘sprouts’ **(called filigree appendages) on the axon terminal of the pre-synaptic neuron (part of synaptogenesis)
Rerouting
neural plasticity
A result of adapting our behaviours (i.e., learning more efficient ways of doing things).
Rerouting involves new connections formed between neurons to establish alternative neural pathways
Synaptic pruning
Excess neurons and synaptic connections are eliminated in order to increase the efficiency of neuronal transmissions.
Inefficient pathways are pruned/eliminated, prioritising more direct and efficient pathways.
