chapter 2 definitions Flashcards
central nervous system
Major division of nervous system comprising the brain and spinal cord, which receives neural messages from and transmits neural messages to the peripheral nervous system
Brain
Complex organ contained within the skull that coordinates mental processes and behaviour, and regulates bodily activity
Spinal cord
Cable of nerve tissue extending from brain, connecting it to peripheral nervous system
Peripheral nervous system
Major division of nervous system comprising every neuron in body outside the central nervous system
Somatic nervous system
Division of peripheral nervous system that transmits neural messages related to voluntary motor movement
Skeletal muscles
Muscles connected to skeleton that carry out voluntary motor movements
Autonomic nervous system
Division of peripheral nervous system that regulates visceral muscles, organs, and glands, und transmits neural messages to the central nervous system about their activity
Visceral muscles, organs, and glands
Muscles, organs, and glands not connected to skeleton that are predominantly self-regulating and do not require conscious control. E.g. Heart, lungs, etc.
Sympathetic nervous system
Division of autonomic nervous system that activates visceral muscles, organs and glands, preparing body to respond to a threat or stressor
Parasympathetic nervous system
Division of autonomic nervous system that maintains optimal and balanced functioning of visceral muscles, organs, and glands
Neuron
Nerve cell that receives and transmits neural information
Motor neuron (efferent neuron)
Neurons that transmit neural messages about motor movement from central nervous system to peripheral nervous system
Sensory neurons (efferent neurons)
Neurons that transmit neural messages about bodily sensations from peripheral nervous system to central nervous system
Interneurons
Neurons that transfer neural messages between sensory neurons and motor neurons
Conscious response
Deliberate and voluntary action that is initiated by brain and performed by the body
Sensory receptor
Nerve ending that detects internal sensations in the body and external sensations from environment
Unconscious response
Any response performed without conscious awareness
Spinal reflex
Unconscious response to sensory stimuli initiated by interneurons in spinal cord independently of the brain
Reflex arc
Path along which the neural signal is transmitted as part of spinal reflex
Neural synapse
Region including axon terminals of presynaptic neuron, synaptic gap, and dendrites of the post synaptic neuron
Pre synaptic neuron
Neuron that releases neurochemicals into the neural synapse
Axon terminal
End of neuron that releases neurochemicals into neural synapse
Synaptic gap
Space between presynaptic neuron and postsynaptic neuron
Postsynaptic neuron
Neuron that receives neurochemicals from neural synapse
Dendrite
Branched extension of neuron which receptor sites are located
Receptor site
Protein molecule on dendrites of neuron that receives neurochemicals
Neurochemicals
Chemical substance that transmits neural information within nervous system
Synaptic transmission
Chemical conveyance of neural information between two neurons across neural synapse
Neurotransmitter
Chemical molecule that has an effect on one or two postsynaptic neurons
Action potential
Electrical impulse that travels down the axon of a neuron
Excitatory effect
When neurotransmitter increases likelihood of postsynaptic neuron firing an action potential
Glutamate
Main excitatory neurotransmitter in nervous system
Inhibitory effect
When neurotransmitter decreases likelihood of postsynaptic neuron firing an action potential
GABA (gamma-aminobutyric acid)
Main inhibitory neurotransmitter in nervous system
Neuromodulator
Chemical molecule that has an effect on multiple postsynaptic neurons
Dopamine
Neuromodulator primarily responsible for voluntary motor movement, the experience of pleasure, and reward-based learning
Serotonin
Neuromodulator primarily responsible for regulation of mood and sleep
Synaptic plasticity
Ability of synaptic connectionsto change over time in response to activity or experience
Sprouting
Ability of dendrites or axons to develop new extensions or branches
Rerouting
Ability of neuron that is connected to a damaged neuron to create an alternative synaptic connection with an undamaged neuron
Pruning
Elimination of synaptic connections that are not adequately activated
Learning
Process of acquiring knowledge, skills, or behaviours through experience
Memory
Process of encoding, storing, and retrieving information that has been previously encountered
Long-term potentiation
Long-lasting and experience-dependent strengthening of synaptic connections that are regularly coactivated
Long-term depression
Long-lasting and experience-dependent wakening of synaptic connections between neurons that are regularly coactivated
