Chapter 2 Nervous System Flashcards
Central Nervous System
Brain and spinal cord
-Receives info from the PNS, sends info to PNS
-Contains interneurons
Spinal Cord
column of cable-like nerve fibres that extend from the base of the brain to the lower back.
S.A.M.E
Sensory afferent- to brain
Motor efferent- from brain
Peripheral Nervous System
comprised of all other part of the body such as muscles, organs and glands.
-Sensory/Motor Neurons
-Sends sensory to CNS
-Receives motor from CNS
Somatic Nervous System
part of the PNS, a network of neurons that carry info from receptor sites to the CNS, then messages the skeletal muscles to create voluntary movement.
Autonomic Nervous system
Part of the PNS, a network of neurons that relay info between the CNS, and organs/glands, regulating them without conscious awareness
Sympathetic Nervous System
is a branch of the ANS that prepares the body for vigorous activity.
-Activates the Flight/Fight/Freeze response
Fight/Flight Response
SNS is activated in response to fear
Freeze response
a result of both the PNS and SNS clashing, with the PNS overpowering the SNS, therefore voluntary movements are inhibited
Parasympathetic nervous system
a branch of the ANS that regulates homeostasis and calms the body down after vigorous activity
Enteric nervous system
part of the ANS that regulates digestive functions by detecting the psychological state of the gastrointestinal tract through neurons and ganglia
Sensory neurons
afferent neurons, that transmit sensory info from your body to your brain.
motor neurons
efferent neurons, that transmit motor info from your brain to your body
interneurons
transmit info between sensory and motor neurons
spinal reflex
an unconscious response initiated by neurons in the spinal cord.
-shortens the journey for sensory neurons to travel to the spinal cord instead of the brain, sending back motor neurons
polysynaptic reflex
when the sensory and motor sites are different
monosynaptic reflex
when both the sensory and motor site are the same
terminal buttons
release a chemical substance called a neurotransmitter to a receiving neuron.
Neutransmission
- Neural impulses travel from the dendrite to the axon terminals.
- The Terminal buttons release a chemical substance.
- The substance crosses the synapse.
- The neurotransmitter is picked up by the dendrites of the other neuron.
Resting potential
They are negatively charged inside, positive outside
-when neural impulse is initiated by the soma, the negative charges inside turn positive and vice versa.
Neurotransmitters
a chemical substance released by the terminal button of a neuron.
-Stored in synaptic vesicles
-Targets a single postsynaptic neuron
Excitatory neurotransmitters
increase the chance of an action potential
Glutamate
an excitatory neurotransmitter involved in memory and learning.
Inhibitory neurotransmitters
decrease the chance of an action potential
GABA
an inhibitory neurotransmitter involved in calming feelings like anxiety
Neuromodulator
a chemical messenger that enhances signal transmission
-Effective on a group of neurons.
-Still chemicals.
-Released outside the neuron into neural tissue.
-Slow acting
dopamine
is a neuromodulator that is involved with motivation, drive and motor movement.
-Mainly Excitatory, sometimes inhibitory
serotonin
is a neuromodulator that is involved with mood stabilisation.
-Inhibitory
-Involved in digestion, metabolism, and stress.
-Modulates behavioural processes including mood.
-Produced mostly in intestines.
neuroplasticity
is the brain’s ability to change itself in response to experience.
developmental plasticity
neuroplasticity that occurs naturally over your life
-Some stages in life can have greater plasticity
adaptive plasticity
occurs due to brain damage or trauma
-When you use critical periods for developmental plasticity, it enables greater adaptive plasticity.
memory trace
a physical or chemical change that forms and stores memories
synaptic plasticity
when synaptic connections change over time in response to experience.
long-term potentiation
the long-lasting and experience-dependent strengthening of synaptic connections that are regularly activated
-Glutamate increases, post-synaptic receptors increase and are more efficient.
-Occurs through high-frequency stimulation of the neural pathway.
-Learning and memory improve due to neurons transmitting info better.
-The more we do something, the stronger the post/pre-synaptic neurons wire together
long-term depression
is when long-lasting and experience-dependent synaptic connections are weakening
-Glutamate and receptors decrease and become less efficient.
-Occurs from no regular activation.
-Dendrites of postsynaptic neurons decreased
neural processes
involve the sprouting, rerouting and pruning of synaptic connections.
sprouting
new dendrites appearing over time in response to experience
rerouting
involves when a neuron connected to a damaged neuron creates an alternate synaptic connection.
pruning
involves the elimination of synaptic connections that are not frequently used.
