General term for any process (ason or dentrite) projecting from the cell of a neuron.
A neuronal process that carries electriacal signals, usually graded potentials, toward the cell body.
Multilayered lipid and protein covering, formed by Schwann cells and oligodendrocytes, around axos of many peripheral and central nervous system neurons.
One of the 31 pairs of nerves that originate on the spinal cord from posterior and anterior roots.
A hormone secreted by the adrenal medulla that produces actions similar to those result from sympathetic stimulation. Also called noradrenaline
The breakdown of Nissl bodies into finely granular masses in the cell body of a neuron whose axon has been damaged
one of the two subdivisions of the atonomic nervous system, having cell bodies of preganglionic neurons in nuclei in the brain stem and in the lateral gray horn of the sacral portion of the spinal cord; primarily concerned with activities that conserve and restore body energy.
Espanded distal end of an axon terminal that contains synaptic vesicles. Also called a synaptic knob.
Synaptic end bulb
A mass of nerve tissue located in the vertebral canal from which 31 pairs of spinal nerve originate.
A sunaptic arrangment in which the synaptic end bulbs of one presynaptic neuron terminate on several postsynaptic neurons.
One of a variety of molecules within axon terminals that are released into the synaptic cleft in response to a nerve impulse and that change the membrand potential of the postsynaptic neuron
Usually a group of nueronal cell bodies lying outside the central nervous system. Plural is ganglia
The part of the central nervous system contained within the cranial cavity
The peripheral, nucleated cytoplasmic layer of Schwann cell. Also called sheath of Schwann.
Neurons that carry sensory information from cranial and spinal nerves into the brain and spinal cor or form a lower to higher level in the spinal cord and brain. Also called sfferent neurons.
Degeneration of the portion of the aoxon ad myelin sheath of a neuron distal to the site of injury
Flat neuroglial cells that surround cell bodies of peripheral nervous system ganglia to provide structural support and regulate the exchange of material between a neronal cell body and interstitial fluid.
Neurons whoes axons extend only for a short distance and contact nerby nearby neurons in the brain, spinal cord, or a ganglion; they comprise the vast majority of neurons in the body
Aggregations or bundles of myelinated and unmyelinated axons located in the brain and spinal cord.
the part of the nervous system that is embedded in the submuccosa and muscularis of the gastrointestinal tract; governs motility and secretions of the GI tract.
Enteric nervous system
an organ of the body, either a muscle or a gland that is innervated by somatic or autonomic molor neurons.
Movement in which a part of the body moves inferiorly
A neuroglial cell of the peripheral nervous system that forms the myelin sheath and neurolemma around a nerve axon by wrappying around the axon in a jelly-roll fashion.
Aneurotransmitter liberated by many peripheral nervous system neurons and some central nervous system neurons. It is excitatory at neuromuscular junctions but inhibitory at some other synapses (for example, it slows heart rate)
Any stres tht changes a controlled condition; any change in the internal or external environment tha excites a sensory receptor, a neuron, or a muscle fiber.
A bundle of nerve axons in the central nervous system.
Visceral sensory (afferent) and visceral motor (efferent) neurons. Autonomic motor neurons, both sympathetic and parasympathetic, conduct nerve impulses from the centeral nervous system to smooth muscle, cardiac muscle, and glands. So named because this part of the nervous system was throught to be self-governing or spontaneous.
Autonomic nervous system
That portion of the nervous system that consists of the brain and spinal cord
Central nervous system
An electrical signal that propagates alond the membrane of a neuron or muscle fiber (cell); a radpid change in the membrane potential that invovles a depolarization followed by a repolarization. Also called a nerve action potential or nerve impusles as it ralates to a neuron, and a muscle action potential as it rlates to muscle fiber.
Membrane-enclosed sac in a synaptic end bulb that stores neurotransmitters.