33 terms

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Neuron
A specialized cell transmitting {{nerve impulses}}; a nerve cell
Unipolar
Having only one axon or process
Bipolar
A neuron with two extensions, specialized for transmission of special senses
Multipolar
A neuron that possesses a single axon and many dendrites, allowing for the integration of a great deal of information from other neurons
Nerve
A bundle of fibers that transmits impulses of sensation to the brain or spinal cord, and impulses from these to the muscles and organs
Synapse
A junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.
Schwann Cell
A glial cell that wraps around the nerve fiber in the peripheral nervous system, and forms the myelin sheaths of peripheral axons.
Node of Ranvier
A gap in the myelin sheath of a nerve, between adjacent Schwann cells.
Myelin Sheath
The insulating covering that surrounds an axon with multiple spiral layers of myelin, that is discontinuous at the nodes of ranvier, and that increases the speed at which a nerve impulse can travel along an axon.
Cell Body
The nucleus containing central part of a neuron exclusive of its axons and dendrites that is the major structural element of the gray matter of the brain and spinal cord.
Dendrite
A short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body.
Motor Neuron
A nerve cell forming part of a pathway along which impulses pass from the brain or spinal cord to a muscle or gland.
Sensory Neuron
A nerve cell that conducts impulses from a sense organ to the CNS.
Interneuron
A neuron that transmits impulses between other neurons, especially as part of a reflex arc.
Axon
The long threadlike part of a nerve cell along which impulses are conducted from the cell body to other cells.
Terminal End
The terminal processes of certain sensory nerve fibers that end freely in various tissues and serve as neural receptors.
Neurotransmitter
A chemical substance that is released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse, causes the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure.
Receptor
A cell able to respond to a stimulus and transmit a signal to a sensory nerve.
Ion
An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
Protein Pump
Transports protons across membranes to establish an equal concentration of ions on both sides of the membrane.
Sodium and Potassium Protein Gated Channel
Affect the flow of potassium, calcium, sodium, and chloride across the plasma membrane.
Action Potential
The change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell.
Depolarization
Phase of an action potential that has changed the membrane potential to a positive value. Occurs before repolarization.
Repolarization
Refers to the change in membrane potential that returns it to a negative value just after the depolarization.
Reflex
An action that is performed as a response to a stimulus and without conscious thought.
Neurologic Disease
Diseases of the brain, spine, and the nerves that connect them. There are more than 600 diseases of the nervous system. (Brain tumors, Epilepsy, Parkinson's disease, Dementia)
Somatic Nervous System
(Voluntary Nervous System) is part of the Peripheral Nervous System associated with the voluntary control of body movements via skeletal muscles. The SoNS consists of sensory nerves and motor nerves.
Peripheral Nervous System
The nervous system outside the brain and spinal cord.
Autonomic Nervous System
The part of the nervous system responsible for control of the bodily functions not consciously directed, such as breathing, the heartbeat, and digestive processes.
Central Nervous System
The complex of nerve tissues that controls the activities of the body. In vertebrates it compromises the brain and spinal cord.
Parasympathetic System
The part of the involuntary nervous system that serves to slow the heart rate, increase intestinal and glandular activity, and relax the sphincter muscles.
Sympathetic System
The part of the Autonomic Nervous System that contains chiefly adrenergic fibers and tends to depress secretion, decrease the tone and contractility of smooth muscle, and in increase heart rate.
Effector
An organ or cell that acts in response to a stimulus