Nervous system Flashcards
What does the nervous system do?
Allows the brain to receive and respond to information from both inside and outside the body,
What are the three main functions of the NS?
Receive information
Process information
Coordinate a response
Two main divisions of the NS?
Central nervous system, peripheral nervous system
What is the function of the CNS?
To receive information from the PNS, processes a response and then respond.
What does the CNS comprise of?
Brain and spinal cord
What is the spinal cord?
A cable like column of nerve fibers/tissues that extend from the base of the brain to the lower back.
What is the spinal cords functions?
Pass sensory information, receive motor information
What are the two Tracts?
Sensory/afferent, TOWARDS brain
Motor/efferent, AWAY from brain
‘SAME’
What does the PNS comprise of?
Muscles, organs and glands
What is the PNS’ function?
Carry information from the sensory organs and internal organs to the CNS (via sensory neurons)
Conveys information from the CNS to the muscles, organs and glads (via motor neurons, called efferent neurons)
What are the PNS divisions?
Somatic and Autonomic
What does the somatic nervous system do?
Carries information from the CNS to the muscles that control movement
What are skeletal muscles?
Muscles that are attached to bones and which control voluntary movement
Is the SNS a voluntary or involuntary system?
Voluntary
What is a voluntary system?
A system that enables us to voluntarily feel sensations(sensory/afferent neurons), and move body parts (motor/efferent neurons)
What is the autonomic nervous system?
A network of nerves that connects the CNS with the body’s visceral muscles, organs and glands, providing feedback to the brain about what they’re up to
Is the ANS a voluntary or involuntary?
Involuntary
What actions is the ANS responsible for?
- heart rate
- breathing rate
- digestion
- perspiration
What are the divisions of the ANS?
Sympathetic nervous system and parasympathetic nervous system
What does the sympathetic nervous system do?
Activates the visceral muscles, organs and glands to prepare the body for vigorous activity, or to deal with a stressful or threatening situation
FIGHT-FLIGHT-FREEZE
What does the parasympathetic nervous system do?
Returning the body to a state of calm, once the stress/threat is no longer present.
Maintains homeostasis
Why does the Parasympathetic nervous system take longer to return the body to its normal state?
This is due to the lingering presence of the hormones released when the sympathetic nervous system is activated, they remain in the bloodstream.
What is a conscious response?
A reaction to a sensory or internally sourced stimuli that involves awareness
What is an unconscious response?
Sensory stimulus that does not involve awareness
What is the spinal reflex?
An automatic response that is initiated by neurons (interneurons) in the spinal cord, instead of the brain
What is the presynaptic neuron
The neuron that releases neurochemicals into the neural synapse
What are the axon terminals?
The ends of the neuron that releases neurochemicals into the neural synapse.
What is the synaptic gap?
The space between the presynaptic neuron and the postsynaptic neuron.
What is the postsynaptic neuron?
The neuron that receives neurochemicals from the neural synapse.
What are dendrites?
Branched extensions of a neuron on which the receptor sites are located.
What are the receptor sites?
Protein molecules on the dendrites of a neuron that receive neurochemicals.
What are neurochemicals?
A chemical substance that transmits neural information within the nervous system
What is synaptic transmission?
The chemical conveyance of neural information between neurons.
What are neurotransmitters?
A chemical molecule that has an effect on one or two postsynaptic neurons.
What is an excitatory neurotransmitter?
Have an excitatory effect, when the neurotransmitter increases it’s likelihood of the postsynaptic neuron firing an action potential.
What is an inhibitory neurotransmitter?
Have an inhibitory effect, when the neurotransmitter decreases it’s likelihood of the postsynaptic neuron firing an action potential.
What is Glutamate?
The main excitatory neurotransmitter in the nervous system
What is Glutamates function?
Increases the likelihood of the postsynaptic neuron firing an action potential.
What does GABA stand for?
Gamma aminobutyric acid
What is Gamma aminobutyric acid?
The main inhibitory neurotransmitter
What is Gamma aminobutyric acid’s function?
Decreases the likelihood of the postsynaptic neuron firing an action potential.
What is a neuromodulator?
A chemical molecule that has an effect on multiple postsynaptic neurons
What are the two main neuromodulators?
Dopamine and serotonin
What is Dopamine?
a neuromodulator
primarily responsible
for voluntary motor
movement, the experience
of pleasure, and reward based learning
What is serotonin?
A neuromodulator
primarily responsible for
the regulation of mood
and sleep
What is the difference between learning and memory?
Learning is the acquisition of skill or knowledge, whereas, memory is the expression of what you have acquired.
When does Plasticity occur?
From embryonic development and take place throughout the lifespan.
What is neural plasticity?
The ability of the brain’s neural structure or function to be changes by experience throughout the lifespan.
What is synaptic plasticity?
The ability of the synapse to change over time.
What is Hebb’s rule?
“Neurons that fire together, wire together”
How does long term potentiation come to be?
Postsynaptic neurons become more and more responsive to the presynaptic neurons as a consequence of repeated stimulation by neurotransmitters.
What are the structural changes of long term potentiation?
- Increase in dendrites, bushing
- Increase in receptor sites
- Increase in number of vesicles
What are the functional changes in long term potentiation?
- Increase in neurotransmitters in vesicles
- More neurotransmitters secreted into synaptic gap
What is long term potentiation?
The long-lasting strengthening of synaptic connections
What is long term depression?
The long-lasting decrease in strength of synaptic transmission
How does long term depression occur?
From the lack of stimulation of pre and post synaptic neurons, or prolonged low level stimulation.
What are the structural changes of long term depression?
pruning of synaptic connections may occur
What are the functional changes of long term depression?
- decrease in neurotransmitters in vesicles
- less neurotransmitters secreted into synaptic gap
