Chapter 3 - Nervous system functioning Flashcards
autonomic nervous system
a subdivision of the peripheral nervous system that controls the body’s internal environment in an autonomous or self-regulated manner (without conscious awareness) - directly connected to organs, glands and visceral muscles - responsible for basic life processes - has a major role in the experience of stress, fear and anger
brain
a complex structure that receives and processes sensory stimuli from the body and coordinates responses, including voluntary movements, emotions and conscious thought. - communicates with the body via the spinal cord and cranial nerves
central nervous system
the brain and the spinal cord; processes and coordinates responses to sensory stimuli. - integrates and coordinates all incoming (sensory/afferent) information and initiates outgoing (motor/efferent) messages to be sent to the body.
conscious response
any response of the nervous system that requires awareness
cranial nerve
connect the brain directly to various organs and muscles of the body - considered to be a part of the peripheral nervous system
dendritic spine
a dendrite fibre that grows by sprouting on the post-synaptic
dopamine
a multifunctional neurotransmitter with both excitatory and inhibitory effects, that is involved in many central nervous system functions such as movement, pleasure, attention, mood, cognition and motivation - is a modulating neurotransmitter or neuromodulator because it reinforces the neural activity in regions of the brain associated with these functions, for example the reward pathway.
excitatory effect
the increased likelihood that the post-synaptic neuron will fire an action potential or neural impulse
filigree appendage
a fibre that grows by sprouting from the axon terminal of the presynaptic neuron
gamma-aminobutyric acid (GABA)
the main inhibitory neurotransmitter in the nervous system, associated with anxiety, specific phobias and Parkinson’s disease
glutamate
the main excitatory neurotransmitter in the nervous system, which is involved with learning and memory by stimulating essential structural and functional changes to the connections between neurons
inhibitory effect
the decreased likelihood that the post-synaptic neuron will fire an action potential or neural impulse
interneuron
a nerve cell in the spinal cord that connects motor and sensory neurons by relaying information between the two
long-term depression (LTD)
the relatively permanent weakening of synaptic connections as a result of repeated low-level activation
long-term potentiation (LTP)
the relatively permanent strengthening of synaptic connections as a result of repeated activation of a neural pathway
motor neuron
a nerve cell that transmits motor impulses from the spinal cord to the skeletal and smooth muscles
neural transmission
an electrical impulse that occurs when a neuron is activated or fires (aka an action potential) -> causes transmission of a signal to post-synaptic neuron - when an action potential travels down an axon and into an axon terminal, it triggers chemical changes within the terminal. -> causes the synaptic vesicles to merge with the membrane at the presynaptic terminal and release neurotransmitters into the synaptic gap
neuromodulator
a subclass of neurotransmitters that alter the strength of neural transmission, by increasing or decreasing the responsiveness of neurons to neurotransmitter signals - does not result in excitation or inhibition of a specific neuron. Instead, it can alter both the cellular and synaptic properties of multiple neurons so that neurotransmission between them is altered
neuron
an individual nerve cell that is specialised to receive, process and/or transmit information within the nervous system
neurotransmitter
a chemical produced by neurons that carries messages to other neurons or cells within the nervous system, including muscles, organs and glands
parasympathetic nervous system
a subdivision of the autonomic nervous system that controls the body’s internal environment in an autonomous or self-regulated manner - maintains homeostasis - counterbalances the sympathetic nervous system
peripheral nervous system
all the nerves outside of the central nervous system that carry messages between the central nervous system and muscles, organs and glands throughout the body
pruning
the removal of excess neurons and synaptic connections to increase the efficiency of neuronal transmissions
receptor site
a membrane protein on the dendrites of neurons that receive and detect specific neurotransmitters
rerouting
the formation of new connections between neurons to establish alternative neural pathways
reward pathway
a group of structures in the brain that are activated by rewarding or reinforcing stimuli - controls our responses to natural rewards and is therefore an important determinant in motivation - When we are exposed to these rewarding stimuli, the brain increases the release of dopamine along this reward pathway in the brain, which modulates the brain activity of the structures along it. The more dopamine released within the reward centre, the more a stimulus is sensed as a reward.
sensory neuron
a nerve cell that carries sensory signals throughout the nervous system
sensory receptor
a sensory nerve ending that produces an afferent or sensory impulse when stimulated
serotonin
an inhibitory neurotransmitter that also acts as a neuromodulator, influencing a variety of brain activities
serotonin pathway
serotonin’s neuromodulatory system, which originates in the brainstem and extends to almost all areas of the cerebrum including the cerebral cortex
somatic nervous system
a subdivision of the peripheral nervous system that carries sensory information to the central nervous system and motor information to the body
spinal cord
a dense bundle of nerves that carries sensory information from the body to the brain and motor information from the brain to the body
spinal reflex
an involuntary and unconscious response to a stimulus involving the spinal cord, which occurs without input from the brain when a quick response is important for your survival.
sprouting
the growth of axon or dendrite fibres at the synapse
sympathetic nervous system
a subdivision of the autonomic nervous system that increases our arousal, readying the body for a quick response (FFF) - dominant in response to perceived threats and stressful psychological or physiological stimuli - pupils dilate - heart rate, blood pressure & breathing rates increase - inhibits digestion - increased sugar and fat release
synapse
the point of communication between two neurons or between a neuron and a target cell such as a muscle or a gland
synaptic gap
the space between the axon terminal of the presynaptic neuron and the membrane of the post-synaptic neuron
synaptic plasticity
specific changes that occur within the synapse, between neurons
synaptic vesicle
a membrane-bound sphere filled with neurotransmitter molecules
synaptogenesis
the formation of new synapses between activated axon terminals and new dendritic spines
unconscious response
any response of our nervous system that does not require awareness
spinal reflex processes
1 - sensory stimulus detected by sensory receptors -> produce and afferent/sensory impulse
2 - sensory neurons transmit sensory information about the stimulus towards the spinal cord
3 - sensory information relayed to interneurons in the spinal cord -> an adaptive motor response is initiated by the interneurons without input from the brain
4 - information about this motor movement is relayed to motor neurons, which transmit the motor impulses from the spinal cord to the skeletal and/or smooth or visceral muscles
5 - muscles are activated to perform the movements required
