nervous system Flashcards
what does the central nervous system consist of?
The brain and the spinal cord
what is the function of the central nervous system
to process information received from the body’s internal and external environment and initiate appropriate responses
what does the peripheral nervous system consist of?
the entire network of nerves outside of the brain and the spinal cord.
What does the PNS do?
carry and transmit information between the spinal cord and the body’s muscles, organs, glands, etc.
what are the two distinct function of the spinal cord?
- carry sensory information from the PNS towards the brain for processing.
- Carry motor information from the brain to the PNS, so that the muscles glands and internal organs respond in a particular way.
what are the components of the PNS?(other nervous systems)
- The Autonomic nervous system
- sympathetic nervous system
- parasympathetic nervous system
- enteric nervous system - somatic nervous system
what is the somatic nervous system?
a sub-division of the PNS that can carry sensory and motor information. it is responsible for all conscious and voluntary movement.
what is the Autonomic nervous system?
is the sub-division of the PNS that connects the CNS to the internal organs (I.e. heart,stomach, liver) and glands (I.e sweat gland, adrenal glands)
it is called autonomous because the organs and glands are typically self-regulating meaning they can operate without conscious effort/control
what is the enteric nervous system?
Refers to neurons embedded within the walls of the gastrointestinal tract that control how the organs operate.
what is the enteric nervous system involved in?
Gut and intestine muscle movement
production of gastric acid
changes to blood flow
water and nutrition absorbtion
signalling being full or empty
vomit and/or diarrhoea for food poisoning,bacteria, etc.
what are the types of neurons ?
sensory neurons- specialised to recieve sensory information from the external environment and within the body and transmit it towards the CNS for processing.
motor neurons- specialised to transmit messages from the CNS towards the muscles, glands and organs for movement
interneurons- carry messages between sensory and motor neurons. they only exist in the CNS. when sensory information arrives at the spinal cord, the interneurons- will receive, organise and integrate the information before responding.
what is the spinal reflex and what are the biological processes involved in the spinal reflex?
An unconscious, involuntary and automatic response to certain stimuli, that doesn’t require involvement of the brain. it is also called a reflex and or a withdrawal reflex.
- sensory receptors in the skin detect the potentially harmful stimuli and relay information to the sensory neurons-.
- sensory neurons- carry information to the spinal cord.
- interneurons in the spinal cord receive the information and immediately relay a message to the motor neurons.
- motor neurons carry the message to the relevant muscle(s)
- the muscle(s) react to allow the limb to get away from the object.
- The interneurons also allow the sensory information to continue up the spinal cord so that it can reach the brain for processing.
what are the different parts of a neuron
axon
soma
dendrites
myelin
axon terminals
terminal buttons
what does the sympathetic nervous system do?
activates the internal muscles, organs and glands to prepare the body for vigorous activity or two deal with a stressful/threatening situation.
what does the Autonomic nervous system do?
works to maintain ones normal state of functioning, once the stressor/threat has passed.
how do neurons communicate?
for a pair of neurons to communicate, neurotransmitters must be released from the terminal buttons of the pre-synaptic neuron, cross the synaptic gap and bind to a receptor site on the dendrite of the postsynaptic neuron.
what is the lock and key process?
reaching a receptor site doesn’t guarantee that the neurotransmitter will bind and release it’s message. each neurotransmitter has a chemically distinct shape and this will effect how succesful it is in the binding process
perfect match = bind = message received
close match = bind = message received
significant difference = no bind = message not received.
what is an excitatory neurotransmitter?
some neurons have excitatory effects. these neurotransmitters stimulate or activate the post-synaptic neurons to perform their functions. in turn, they enhance neural transmission along neural pathways.
what is an inhibitory neurotransmitter?
other neurotransmitters have inhibitory effects. these neurotransmitters block or prevent postsynaptic neurons from reacting.
what are neuromodulators
neuromodulators are neurotransmitters that can influence the effectiveness of other neurotransmitters
what is the primary excitatory neurotransmitter?
Glutamate
what is the primary inhibitory neurotransmitter?
GABA ( gamma amino butyric acid)
what is synaptic plastcity
synaptic plasticity is the ability of a synapse to change in response to experience. more specifically and existing synapse can be strengthened and/or eliminated as a result of how often it is used.
what is long term potentiation?
long term potentiation refers to the strengthening of a synapse, through strong and frequent stimulation of the synapse.
