ch 3

a primary neurotransmitter that transmits impulses across the synaptic cleft

a rapid and substantial depolarization of the membrane of a neuron or muscle cell that is conducted through the cell

the sensory division of the peripheral nervous system

a part of the neuron, between the cell body and the axon, that controls traffic down the axon through summation of excitatory and inhibitory postsynaptic potentials

one of numerous branched endings of an axon - terminal fibril

system consisting of the brain and spinal cord

a decrease in the electrical potential across a membrane, as when the inside of a neuron becomes less negative relative to the outside.

the motor division of the peripheral nervous system

branches coming off the ends of the axons leading to the axon terminals

a depolarization of the postsynaptic membrane caused by an excitatory impulse

a sensory receptor in a muscle tendon that monitors tension

a localized change (depolarization or hyperpolarization) in the membrane potential

an increase in the electrical potential across a membrane

a hyperpolarization of the postsynaptic membrane caused by an inhibitory impulse

efferent division

an involuntary motor response to a given stimulus

a sensory receptor located in the muscle that senses how much the muscle is stretched

the outer covering of a myhelinated nerve fiber, formed by a fatlike substance called myelin

the electrical signal conducted along a neuron, which can be transmitted to another neuron or an end organ such as a group of muscle fibers

the site at which a motor neuron communicates with a muscle fiber

a specialized cell in the nervous system responsible for generating and transmitting nerve impulses

a chemical used for communication between a neuron and another cell

a catecholamine released from the adrenal medulla tht, along with epinephrine, prepares the body for a fight-or-flight response. It is also a neurotransmitter

that section of the nervous system through which motor nerve impulses are transmitted from the brain and spinal cord to the periphery and sensory nerve impulses are transmitted from the periphery to the brain and spinal cord

the potential difference between the electrical charges inside a cell and outside the cell, caused by a separation of charges across the membrane

the means of rapid nerve impules conduction along myelinated neurons

the process by which the sensory and motor systems communicate and coordinate with each other

an enzyme called Na+=K+-ATPase, which maintains the resting membrane potential in disequilibrium at -70mV

the summing of all individual changes in a neuron's membrane potential

the junctions between two neurons

a minimum amount of stimulus needed to elicit a response. Also, the minimum depolarization required to produce an action potential in neurons