The Nervous System Flashcards
What is a neuron?
A neuron is a nerve cell
What is a sensory/afferent neuron?
They take a message from a sense organ to the central nervous system
What is a motor/efferent neuron?
They take a message from the central nervous system to a muse or a gland
What is a ganglion?
A group of cell bodies located outside the CNS
What is an interneuron?
They carry information between sensory and motor neurons
What is the threshold?
The threshold is the minimum stimulus needed to cause an impulse to be carried in a neuron
What does the ‘all or nothing’ law state?
It states that if the threshold is reached an impulse is carried, but if the threshold is not reached no impulse is carried
What is the refractory period?
The refractory period is a short time span after a neuron has carried an impulse during which a stimulus fails to cause a response
What is a synapse?
A synapse is a region where two neurons come into close contact
What is a synaptic cleft?
A synaptic cleft is the tiny gap between the two neurons at a synapse
What is a reflex action?
An automatic involuntary, unthinking response to a stimulus
What is a reflex arc?
A reflex arc is the pathway taken by a nerve impulse in a reflex action
