The nervous system and Neurons, Synaptic transmission Flashcards
two types of nervous system
Central and peripheral
components of the central nervous system
the brain:
the spinal cord:
tell me about spinal cord
rely info between body and brain, regulates procces like digestion, voluntary movement, breathing
4 main parts of the brain
(4 main parts) contains of Cerebrum, Cerebellum, Diencephalon and Brainstem
components of peripheral nervous system
somatic and autonomic
Somtic Nervous System
has sensory nerves - they relay info TO cns
has motor nerves - they relay info FROM cns
has 12 pairs of cranial nerves and 32 pair of Spinal nerves
Autoniomic nervous system responcible for
unconscious actions like breathing
components of autonomic nervous system
sympathetic and parasympathetic
sympathetic nervous system
dealing with emergencies. fight or flight. slows down functions like digestion. can increase blood pressure and heart rate.
neurons from here travel to every organ and gland
parasympathetic nervous system
relaxing body after emergencies
sensory neurons
carry impulses form the sense organs TO CNS (the spinal cord and brain)
Relay neruons
allows sensory neuron to communicate with motor neurons.
Where are relay neurons found?
within the brain and spinal cord
motor neurons
carry signals FROM CNS to muscles
neuron
What is the myelin sheath?
covers the axon of some neurons and helps speed neural impulses
neuron
Parts of Neuron
- Cell Body
- Axon
- Myelin sheath
- Nodes of Ranvier
- Dendrits
neuron
what are the dendrits in the neuron
they extend form the cell body and carry electrical impulses FROM other neurons TO cell body
neuron
what is an Axon
extension of the neuron, carries impulses FROM the cell body
neuron
what are the Nodes of Ranvier
gaps between Myelin sheath - action potential (impulse) jamps form node to node
how Reflex happens
stimuli-> sensory receptor-> rely neuron->spinal cord and brain-> motor neron->synapse-> response
more about Motor Neuron
their Cell body lies within CNS, but axon is within PNS. Motor N form synapses - to control muscles - when it`s stimulated - it releases neurotransmitters - creates a muscle movement - axon of Motor N fires - muscle contracts
gap between neurons called -
synaptic cleft
step 1 of the synaptic transmittion
action potential received by the pre-synaptic neurone
step 2 of the synaptic transmittion
action potential stimulates Synaptic Vesicles to release into synapse neurotransmitters
step 3 of the synaptic transmittion
when released they move by defusion and bind with specialised receptors from the post-synaptic area
and so get activated
step 4 of the synaptic transmittion
when activated they produce excitatory or inhibitory effects
step 5 of the synaptic transmittion
the excess of neurotransmitters is either taking back by re-uptake or broken down
the quicker it`s taken the shorter the effects (excitatory)
what are the excitatory effects
switching ON the NS.
It sends a signal to the next Post-synaptic cell and makes it more likely to fire.
e.g. Dopamine
what are the inhibitory effects
Calming down the NS.
It filetrs out unnecessery excitatory signals.
the next neurone is less likely to fire
e.g. GABA, serotonin
how impulse is created part1
neurone is at rest (not active) = negatively charged
how impulse is created part 2
neuron become activated by a stimulus (and the cell body becomes Positively charged) = this is Action potential
how impulse is created part 3
it creates an electric impulse and travels along the axon to the dendrits at the end of neuron
how impulse is created part 4
then Repolarization happens - back to balanse of IPSP and EPSP = resting potential
