162 Ch 5 Reflexes and Reaction Time

action potential

an electrical impulse that travels down the axon of the neuron, triggers the release of neurotransmitters

neurotransmitter

chemical that is used to communicate between neurons

local potential

a small electrical impulse that fades over a distance

excitatory: it can cause that neuron to initate an action potential in its axon

inhibitory: it can cause that neuron to be less likely to initiate an action potential

Afferent (sensory) neurons

convey impulses towards the central nervous system from sensory receptors found throughout the body

Efferent (motor) neurons

convey impulses away from the central nervous system to a target, which can be a muscle or a gland

Interneurons

are found within the central nervous system (brain + spinal cord). They connect affrent and efferent neurons and integrate sensory input and motor input

Reflex

very faft, involuntary response to a stumulus

latency

refers to the amount of time that passes between the initial stimulus and the response

Muscle spindles

muscle fibers with sensory neuron axon terminals wrapped around them

Excitatory synapse

with both the efferent (motor) neuron and the interneuron

Neuron

(nerve cell) is a single cell that specializes in communication via electric impulses

Cell body/Soma

the neuron containing the nucleus + organelles

Dendrites

short projections continuous with the soma and function to receive information

Axon

The single long projection responsible for transmitting information from the cell body to the next cell

Axon hillock

The portion of the axon connecting the cell body is often swollen

Axon terminals

The end of an axon will branch slightly, creating __

Synapse

a junction between to nerve cells, typically between the axon terminals of a pre-synaptic neuron (the neuron sending a signal) and a post-synaptic neuron (the neuron receiving the signal)