Section one - neurons Flashcards
what is the nervous system composed of
is composed of nerve cells call neurons
what do neurons do
carry messages at high speed in electical impulses to different parts of the body
what are many neurons grouped together in single structure called
nerves
what does the CNS stand for?
centeral nervous system
what type of neron carries impulses towards the CNS
sensory neron
what type of neron carries impulses away the CNS to muscels and glands?
motor neuron
what are the three main types of neurons in the nervous system
sensory afferent neurons
internurons
motor efferent neurons
what do sensory afferent neurons do
gather info from sensory recepters and send the info a nerve impulses towards the CNS
what do interneurons do
carry info between sensory neurons and motor neurons
where can you find the interneurons
everywhere in the CNS
what do motor neurons do
sen d info away from the CNS to effector muscels and glands
what do Dendrites do
receve signals from other neurons and relay impaules towards the cell body, have a high surface area to recive signals
what do Soma do
processes input from dendrites, if imput is large enough it will relay the info to the axon
what do axons do
conducs impulese away from the somo
what is the myelin do
helps messages to be trasmitted quickly, it then forms the myelin sheath
the termanal end of axon branches into many fibres called..
axon terminals
what is a synapes
junction between two neurons
the membrains of neurons are sperated by a narrow gap called
the synaptic cleft or synapse
messages are passed across the synapse in the form of chemicals called..
neuronotransmitters
neuronotransmitters
always…
move in the same direction
When an impulse arrives at the end of a neuron, the impulse
causes the sacs containing neurotransmitters to fuse with the
membranes of the axon. These sacs, called
vesicles
what does PNS stand for
Peripheral nervous system
what is the CNS comprised of (made of)
the brain and the spinal cord
