neurons Flashcards
what is a neuron?
located in our CNS. they transmit signals chemically and electrically and provide the nervous system with its primary means of communication.
what are the 3 types of neurons?
sensory
relay
motor
what is the structure of a sensory neuron?
long dendrites and a short axon
what is the function of a sensory neuron?
found in receptors such as eyes, ears, tongue, skin and carry nerve impulses to the CNS. when these nerve impulses reach the brain, they are translated into sensations such as vision, hearing, taste and touch. however, not all sensory neurons reach the brain as some neurons stop at the spinal cord, allow ng for quick reflex actions.
what is the structure of a relay neuron?
short dendrites and a short axon
what is the function of a relay neuron?
they are found between sensory input and motor output response. relay neurons are found in the brain and spinal cord and allow sensory and motor neurons to communicate.
what is the structure of a motor neuron?
short dendrites and long axons
what is the function of a motor neuron?
are found in the CNS and control muscle movements. when motor neurons are stimulated, they release neurotransmitters that bind to the receptors on muscles to trigger response, which can lead to movement.
what are the parts of a neuron?
dendrites
nucleus
cell body
axon
myelin sheath
Schwann cell
node of ranvier
axon terminal
what is the function of the nucleus?
control centre of a cell, controls the cells chromosomal DNA
what is the function of the dendrites?
recieves the nerve impulse or signal from adjacent neurons
what is the function of the axon?
where electrical signals pass along
what is the function of the myelin sheath?
insulates/protects the axon from external influences that might effect the transmission of nerve impulses down the axon
what is the function of the node of ranvier?
speed up transmission of the impulse by forcing it to ‘jump’
what is the function of the axon terminal?
terminal buttons send signals to adjacent cells
