Nervous system definitions Flashcards
What is the CNS?
Consists of the Brain and the Spinal Cord
Brain
Combines and processes information
Decision making
Spinal cord
sends information between peripheral nervous system and brain
Carries out spinal reflex
Summaries the divisions of the nervous system.
Central nervous system
Brain
Spinal Cord
Peripheral nervous system
Somatic nervous system
Sensory component
Motor component
Autonomic nervous system
Sympathetic nervous system
Parasympathetic nervous system
Enteric nervous system
What are the two main functions of the Somatic Nervous System?
Carries sensory information from sensory receptor sites in the body (skin, muscle, joints and tendons) to the CNS
Sends information FROM sense organs TO the CNS via sensory/afferent neurons
Carries motor information from the CNS to the to the skeletal muscles.
Motor information is carried along motor neural pathways by motor/efferent neurons to skeletal muscles to control their activity by causing them to contract or relax.
SAME!!!
Sensory – Afferent – Motor – Efferent
What does the Autonomic Nervous System do?
Regulates and controls the functioning of the internal organs automatically.
This area of the NS is working all of the time and we are unable to control it.
Provides communication from the involuntary (visceral) muscles, glands and organs to the CNS and back again.
Division of the PNS that keeps us alive.
What are the sub division of the autonomic ns?
Sympathetic, Parasympathetic and Enteric NS
Parasympathetic NS?
Calms your body down, conserves energy and returns your body to homeostasis.
Sympathetic NS?
Arouses and increases energy to get the body ready for a threat.
The enteric NS?
The enteric nervous system (ENS) is embedded within the walls of the gastrointestinal tract and is dedicated to its functioning.
What are the three types of neurons?
Sensory, Motor and interneurons
What does the sensory neurons do?
A sensory neuron receives and carries sensory information from both the external and internal environments and transmits to the CNS. It is also called an afferent neuron.
What does the motor neurons do?
A motor neuron carries messagesfromthe CNS to cells in skeletal muscles, organs and glands to stimulate activity. It is also called an efferent neuron.
What do interneurons do?
An interneuron sends messagesbetweensensory and motor neurons within the CNS, relaying information from one to the other (because sensory and motor neurons rarely ever connect directly).
electrical/chemical?
Electrical WITHIN neurons
Chemical BETWEEN neurons – Neurotransmitters
What are the steps to a conscious reponse?
Sensory receptors detect the information and transmit a sensory message along afferent neurons to the spinal cord.
Interneurons in the spinal cord take the information to the brain for processing and to determine a response.
The motor message is transmitted along efferent neurons to effectors to carry out the response.
What are the steps to an unconscious response?
Sensory receptors detect the information
Sensory information is sent along afferent neurons to the spinal cord.
Interneurons in the spinal cord initiate a spinal reflex.
The motor message is transmitted along efferent neurons
to effectors to carry out the response to avoid injury.
Information is sent to the brain for conscious awareness.
What is an excitatory effect?
Excitatory effect: stimulates the post-synaptic neuron making it more likely for the post-synaptic membrane to fire an action potential.
What is an inhibitory effect?
Inhibitory effect: block/inhibit the activity levels of the next neuron, therefore make it less likely for the post-synaptic membrane to fire an action potential.
What are the characteristics of an neurotransmitter?
Fast acting, localised – that is, acting at a singlesynapse – and short lived
Examples are Glutamate and GABA
What are the characteristics of a neuromodulator?
- Slower acting
- Targets a broader area
What is GABA
the primary inhibitory neurotransmitter in the central nervous system, making postsynaptic neurons less likely to fire
What is gluamate?
glutamate the main excitatory neurotransmitter in the CNS, thereby enhancing information transmission by making postsynaptic neurons more likely to fire.
What is a neuromodulator?
neuromodulator a neurotransmitter that can influence the effects of other neurotransmitters
What is Dopamine?
dopamine a neuromodulator with multiple functions depending on where it acts; functions include roles in coordinating movement, learning and behaviours that are rewarding
What is Serotonin?
serotonin a neuromodulator with multiple functions depending on where it acts; functions include emotional processing, mood, and sleep onset
What is learning?
Learning a relatively permanent change in behavior that occurs as a result of experienceis
What is synaptic plasticity?
Synaptic plasticity is the ability of the synapse to change in response to experience.
What is Long Term Potentiation?
LTP refers to the long-lasting and experience-dependent strengthening of synaptic connections due to repeated co-activation.
What is Long Term Depression?
The long lasting and experience-dependent weakening of synaptic connections, due to repeated low level stiumulation.
What is the neurotransmitter that is involved in LTP and Learning?
Glutamate
What is rerouting?
rerouting when new connections are made between neurons to create alternate neural pathways
What is Sprouting?
sprouting is the creation of new extensions on a neuron (axons or dendrites) to allow it to make new connections with other neurons
What is pruning?
pruning is the elimination of weak, ineffective or unused synapses (and therefore connections to other neurons); also called synaptic pruning
What are the three types of changes that occur at the synapse?
Sprouting, Rerouting and Pruning.
What is the spinal reflex?
Spinal reflex is an unconscious, automatic response controlled solely by neural circuits in the spinal cord (without any involvement of the brain)
