ch 3- nervous system functioning Flashcards
CNS- central nervous system
the brain and spinal cord: processes and coordinates responses to sensory stimuli
brain
a complex structure that receives and processes sensory stimuli from the body and coordinates responses, including voluntary movements, emotions and conscious thought.
spinal cord
a dense bundle of nerves that carry sensory information from the body to the brain and motor information from the brain to the body
spinal reflex
involuntary and unconscious response to a stimulus involving the spinal cord, occuring without input from the brain
sensory receptor
a sensory nerve ending producing an afferent or sensory impulse when stimulated
sensory neuron
a nerve cell that carries sensory signals throughout the nervous system
interneurons
a nerve cell in the spinal cord connecting motor and sensory neurons by relaying information between the two
motor neuron
a nerve cell that transmits motor impulses from the spinal cord to the skeletal and smooth muscles
PNS- peripheral nervous system
all the nerves outside of the CNS, carrying messages between the CNS and muscles, organs and glands throughout the body
SNS- somatic nervous system
subdivision of the PNS carrying sensory information to the CNS and motor information to the body
what is the afferent role of the SNS
afferent refers to sensory- it carries sensory information gathered by our five senses towards the CNS
what is the efferent role of the SNS
efferent refers to motor- it carries motor commands from the CNS to skeletal muscles, enabling voluntary movements
ANS- autonomic nervous system
a subdivision of the PNs that controls the body’s internal environment in an autonomous or self regulated manner
sympathetic nervous system
a subdivision of the ANS increasing our arousal and readying the body for a quick response
parasympathetic nervous system
a subdivision of the ANS controlling the body’s internal environment in an autonomous or self regulated manner
unconscious response
any response of our nervous system that doesn’t require awareness
conscious reponse
any response of the nervous system requiring awareness
neurons
individual nerve cells specialised to receive, process and/or transmit information within the nervous system
neural transmission
an electrical impulse occuring when a neuron is activated or fires
neurotransmitters
chemicals producerd by neurons that carries messages to other neurons or cells within the nervous system. including muscles, organs and glands
synapses
point of communication between two neurons or between a neuron and target cell like a muscle or a gland
synaptic vesicle
membrane bound sphere filled with neurotransmitter molecules
synaptic gap
space between the axon terminal of the presynaptic neuron and the membrane of the most synaptic neuron
receptor site
membrane protein on the dendrites of neurons that receive and detect specific neurotransmitters
excitatory effect
the increased likelihood that the post synaptic neuron will fire an action potential or neural impulse
glutamate
main excitatory neurotransmitter in the nervous system involved with learning and memory
inhibatory effect
decreased likelihood that the post synaptic neuron will fire an action potential or neural impulse
gamma aminobutyric acid or GABA
main inhibitory neurotransmitter in the nervous system, associated with anxiety, specific phobias and parkinsons
neuromodulators
subclass of neurotransmitters that alter the strength of a neural transmission, increasing or decreasing the responsiveness of neurons to neurotransmitter signals
dopamine
multifunctional neurotransmitter with both excitatory and inhibitory effects that is involved in many CNS functions like movement, pleasure, attention, mood, cognition and motivation
reward pathway
a group of structures in the brain that are activated by rewarding or reinforcing stimuli
serotonin
an inhibitory neurotransmitter that also acts as a neuromodulator, influencing a variety of brain activities
serotonin pathway
serotonins neuromodulatory system which originates in the brainstem and extends to almost all areas of the cerebrum including the cerebral cortex
synaptic plasticity
specific changes that occur within the synapse between neurons
long term potentation
relatively permanent strengthening of synapting connections, as a result of repeated activation of a neural pathway
long term depression
relatively permanent weakening of synaptic connections as a result of repeated low level activation
LTP+LTD=
more effeicient neural pathways as a result of neural plasticity
sprouting
growth of axon or dendrite fibres at the synapsed
dendritic spine
a dendrite fibre that grows by sprouting on the post synaptic neuron
filigree appendage
a fibre that grows by sprouting from the axon terminal of the presynaptic neuron
synaptogenesis
formation of new synapses that result from the process of sprouting
rerouting
the formation of new connections between neurons to establish alternative neural pathways
pruning
removal of excess neurons and synaptic connectinos to increase the efficiency of neuronal transmissions
