what do motor neurons do?
efferent neurons transmit neural messages about motor movement from the CNS to the PNS
what do sensory neurons do?
afferent neurons transmit neural messages about bodily sensations from the PNS to the CNS
what do interneurons do?
transfer neural messages between sensory neurons and motor neurons, the CNS is made up of interneurons
what is a neuron?
a nerve cell that receives and transmits neural messages
what is the somatic nervous system?
division of the peripheral ns that transmits neural messages related to voluntary motor movement (skeletal muscles)
what is the autonomic nervous system?
a division of the peripheral nervous system that regulates visceral muscles, organs, and glands, involved in unconscious responses
what are he branches of the autonomic ns?
sympathetic and parasympathetic
what does the parasympathetic ns do?
dominant during everyday life of an individual and calms the body, returning it to homeostasis
what does the sympathetic ns do?
becomes dominant when an individual is confronted with a threat/ stressor, energising the body (includes fight, flight, freeze)
what is the spinal reflex?
an unconscious response to sensory stimuli that is initiated by interneurons in the spinal cord independently of the brain
what is the process of the spinal reflex?
- sensory/ afferent neurons detect t stimuli
- interneuron/ relay neuron link motor and sensory neurone in spinal cord
- motor/efferent neurons enable response
- sensory message continues to travel to the brain & it independently registers the sensation
what is a conscious response?
a deliberate and voluntary action that is intentionally initiated by the brain and performed by the body (if the brain Is involved it is a conscious response)
what is an unconscious response?
an automatic and involuntary action that is performed by the body independently of the brain
what is the process of the brain in the CNS?
- Receives sensory information
- processes, integrates and organises it
- Initiates a bodily response to the skeletal muscles to respond to stimuli
what is the neural synapse?
the region that includes the axon terminals (presynaptic neuron), synaptic gap, and dendrites (postsynaptic neuron), where neurons meet
what is the neural pathway?
- axon terminals of the presynaptic neuron release neurochemicals into the neural synapse
- synaptic gap is the space between the presynaptic neuron and the postsynaptic neuron
- receptor sites on dendrites of the post synaptic neuron receive the neurochemicals
what is the process of the synaptic transmission?
- neurochemicals are produced in the axon terminals of the presynaptic neurons
- neurochemicals are released from the axon terminals of the presynaptic neuron into the synaptic gap
- neurochemicals bind to receptor on the dendrites of the postsynaptic neuron
- neurochemicals affect the postsynaptic neuron, either triggering or inhibiting a response
what are neurotransmitters?
chemical molecules that have an effect on one or two postsynaptic neurons and enable rapid communication between neurons
what are the two types of neurotransmitters?
glutamate (excitatory) and GABA (inhibitory)
what do excitatory neurotransmitters do?
have a stimulatory effect on the postsynaptic neuron, more likely to fire an action potential
what do inhibitory neurotransmitters do?
have a repressive effect on the postsynaptic neuron, less likely to fire and action potential
what are neuromodulators?
chemical molecules that have an effect on multiple postsynaptic neurons and produce relatively long-term effects as they modulate more slowly
What does glutamate do?
(excitatory) neurotransmitter, it has a role in learning and memory as they strengthen synaptic connections that are repeatedly activated during learning, it also has an important role in movement
what does GABA do?
(inhibitory) neurotransmitter, it regulates postsynaptic activation in neural pathways preventing the over excitation of neurons. it reduces anxiety by preventing excitatory neural signals. additionally it inhibits the uncontrolled firing of action potentials and therefore preventing seizures.
