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167 Cards in this Set
- Front
- Back
Abducens
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The cranial nerve that innervates the muscle that abducts the eye.
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Absolute Refractory Period
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The period during which the neuron is functionally unable to generate a second spike, occurring early in the period of repolarization and afterhyperpolarization.
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Acetycholine
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The chemical transmitter used by preganglionic cells.
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Action Potentials
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The electrical signals used for long-distance communication in the nervous system.
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Activation Gate
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Senses the transmembrane potential and can be opened by depolarization.
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Adrenal Medullae
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Endocrine glands that could be thought of as modified sympathetic ganglia.
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Adrenaline
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The main form of catecholamine released by the adult adrenal. Also callled epinephrine.
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Afferent Axons
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Carry information towards the CNS.
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Afterhyperpolarization Phase
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A period during which the membrane potential is even more inside negative than at rest.
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Agonists
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Substances similar enough to be legitimate transmitter to activate the receptor.
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Alpha-Adernergic Receptors
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Receptors for norepinephrine and epinephrine.
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Anterior Commissure
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Smaller and less important fiber tracts that connect corresponding parts of the right and left halves of the CNS.
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Anterior Horns
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Central gray matter is shaped like a capital H and the horns are the arms of the H that project anteriorly.
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Anterior Spinocerebellar Tracts
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Located within the spinocerebellar pathway, carrying information from muscle and joint receptors to the cerebellum.
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Arachnoid Matter
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One of 3 membranes of connective tissue that surround the whole CNS, located between the dura and pia mater.
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Arachnoid Villi
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Fingerlike projections of the arachnoid that act as valves projecting through the dura into dural blood sinuses.
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Association Areas
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In the cerebral cortex, responsible for forming a unified picture of the sensory world, associating key elements of it with the resources of past experience, and formulating complex behaviors.
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Astrocytes
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A class of glial cell in the CNS that control the composition and volume of the fluid microenvironment that surrounds central neurons.
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Autonomic Nervous System
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That part of the peripheral nervous system that supplies motor innervation to the viscera.
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Axon
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A single tubular structure on the neuron cell body that conducts action potentials.
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Axon Hillock
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A single tubular axon that sprouts from the cell body at a bump. Also called an initial segment.
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Axon Terminal
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Structures that allow neurons to communicate with each other and with effectors.
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Basal Ganglia
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Now called basal nuclei, these are islands of neuron cell bodies in the cerebral white matter.
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Beta-Adernergic Receptors
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Receptors for norepinephrine and epinephrine.
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Caudate Nucleus
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Islands of neuronal cell bodies in the cerebral white matter that are involved in the control of movement.
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Central Canal
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The central gray matter is shaped like a capital H. The crossbar of the H is the central commissure and contains the hollow central canal.
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Central Commissure
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The central gray matter is shaped like a capital H. The crossbar of the H is the central commissure.
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Cerebellum
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Coordinates and smooth body movements, particularly rapid ones.
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Cerebral Aqueduct
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Connects the 3rd and 4th ventricle, running thru the midbrain, dividing it into a dorsal tectum and paired ventral cerebral pednucles.
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Cerebral Peduncles
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Structures found in the fourth ventricle.
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Cerebrospinal Fluid (CSF)
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Secreted by the choroid plexus, it circulates throughout the ventricles and the subarachnoidal space, providing cushion that gives some protection to the brain and spinal fluid.
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Chemical Synapse
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The most common form of synapse in which the axon terminal releases a specific neurotransmitter chemical that acts on the plasma membrane of the target cell, either to excite or to inhibit electrical activity in the recipient cell.
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Choroid Plexus
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A membrane attached to the roofs of the four ventricles that secretes CSF.
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Closed State
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A Na+ channel state in which the pore is blocked by an internal activation gate that senses the transmembrane potential and can be opened by depolarization, switching the channel to the open state.
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Commissures
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Fiber tracts that connect corresponding parts of the right and left halves of the CNS.
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Convergent
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Several pathways, possibly carrying different types of information, may make synapses on the same neurons.
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Corpus Callosum
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The major commissure.
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Cortex
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The bulk of the gray matter of the brain.
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Cortical Dominance
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A critical area located in only one hemisphere.
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Decremental Threshold
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Stimulation of the dendrites results in a local depolarization that decreases in intensity as it travels through the dendrites to the cell body.
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Decussate
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Both sensory and motor pathways cross from one side of the CNS to the other before they enter or leave the brain.
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Deep Cerebellar Nuclei
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Embedded within the cerebellum's core of white matter.
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Depolarization
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Any change in the direction of a less-negative potential.
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Diencephalon
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A division of the prosencephalon vesicle, containing the thalamus and hypothalamus regions.
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Direct Corticospinal Pathway
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The pyramidal tracts that carry axons of neurons in the motor cortex and traverse the cord without synapsing until they reach neurons in the spinal segments.
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Dorsal Column Pathway
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A pathway located in the posterior funiculus occupies a wedge-shaped sector of the medial posterior cord and carries information about fine touch and pressure sensations.
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Dorsal Ramus
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A spinal nerve branch.
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Dorsal Root Ganglion
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Contains the cell bodies of somatic sensory afferents.
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Dorsal Roots
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Each spinal segment has a pair that projects from the postereolateral surface of each side.
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Efferent Axons
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Carry commands to effectors.
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Endoneurim
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Encloses each axon.
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Ependymal Cells
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A class of glial cells in the CNS.
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Epineurium
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A sheath that encloses the entire peripheral nerve.
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Epithalamus
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One of the principal diencephalic structures forming the roof of the third ventricle and containing the pineal gland.
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Excitatory Postsynaptic Potential (EPSP)
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Postsynaptic potentials that increase the likelihood that the postsnyaptic cell will initiate an action potential at the axon hillock.
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Extrapyramidal Tracts
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Originate in brain stem nuclei that receive input from the basal nuclei and cerebellum, control mainly the muscles of the axial skeleton, and mediate less finely controlled movements of the trunk.
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Fourth Ventricle
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The hindbrain, connected to the 3rd ventricle by the cerebral aqueduct.
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G Protein
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A membrane protein (short for GTP-binding protein) that consists of three subunits designated alpha, beta and gamma.
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General Association Area
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Large parts of the temporal, parietal, and occipital lobes that appear to be critical for integrating multiple modes of sensory information into a comprehensive understanding of the situation.
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General Somatic Senses
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A class of somatic sensory system that includes touch, temperature, and pain that project from the body surface, as well as muscle, tendon, and joint receptors that give info about position and movement of the body in space.
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Glia
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The supporting cells of the nervous system.
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Glassopharyngeal
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A cranial mixed nerve that serves part of the tongue and throat. Carries gustatory afferents from posterior tongue/carotid sinus/carotid body that convey info about blood and blood pressure.
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Gray Matter
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The central matter of the spinal cord and much of cortex.
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Gray Ramus
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A medial spinal nerve branch that connects the base of each ventral ramus to a corresponding sympathetic chain ganglion, part of sympathetic branch of autonomic motor system.
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Guanylyl Cyclase
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Converts guanosine triphosphate (GTP) to cyclic guanosine monophosphate (cGMP).
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Gyri (Gyrus)
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Ridges that are created by folding the cortex as is grows.
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Homunculus
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A map of the cortex representing the body surface.
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Hyperpolarization
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Any change in the direction of an even more inside-negative potential.
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Hyperpolarizing Inhibitory Postsynaptic Potential
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Postsynnaptic potentials that trend to decrease the likelihood that the postsynaptic cell will initiate an action potential at the axon hillock.
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Hypoglossal
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The cranial nerve that innervates the muscles of the tongue.
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Inactivated State
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When the inactivation gate remains closed, the channel cannot be reopened by depolarization.
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Inactivation Gate
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Once the channel has entered the open state this gate can swing into place and close the channel. While the inactivation gate remains closed, the channel cannot be reopened by depolarization.
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Inferior Hypogastric Ganglia
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1 of 4 major unpaired prevertebral ganglia located in the abdomen and pelvis.
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Inferior Mesenteric Ganglia
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1 of 4 major unpaired prevertebral ganglia located in the abdomen and pelvis.
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Initial Segment
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A singular tubular axon that sprouts from the cell body at a bump. Also called the axon hillock.
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Interneurons
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Also called associated neurons, these are most numerous neurons that have their processes entirely within the CNS and are involved in processing information for an appropriate response.
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Internodes
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Regular intervals in which myelinated axons are surrounded by a mulitlayered sheath formed by ganglia.
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Inotropic Receptors
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One type of neurotransmitter receptor that is also an ion channel. Binding of the transmitter to the ionotropic receptor opens the channel, resulting directly in a permeability change.
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Lateral Spinothalamic Tracts
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Contains the spinothalamic pathway.
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Lateral Ventricles
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The paired, C-shaped ventricles within the cerebral hemispheres.
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Longitudinal Fissures
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Separates the cerebrum into R and L hemispheres.
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Medulla Oblongta
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A region of the brain stem.
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Melatonin
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A hormone secreted by the pineal gland, contributes to control of the body sleeping-waking cycle.
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Meninges
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3 membranes of connective tissue that surround the whole CNS. The outermost membrane is tough dura mater. Just deep to the dura is the arachnoid, and inside that the pia mater.
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Mesencephalon (midbrain)
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The midbrain portion of the brain stem.
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Metabotropic Receptor
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A receptor that is coupled to intracellular second messengers by way of the G proteins and may be coupled to different second messenger systems in different cell types.
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Metencephalon
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The cerebellum and pons portion of brain stem.
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Microglia
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The cells of nonspecific immune system rather than true glia cells--they are the form that macrophages take in brain.
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Midbrain
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Also known as the mesencephalon, located within the brain stem.
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Mixed Nerves
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Nerves that contain both afferent and efferent axons.
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Monoamine Oxidase
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An enzyme that packages for reuse or breaks down any given molecule of recovered norepinephrine.
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Monsynaptic Stretch Reflex
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The only human reflex that is monosynaptic, in which there are no interneurons in the reflex arc and all integration takes place as synapses of the sensory neurons on the motor neurons. A stretch reflex may be evoked tapping on a muscle or its tendon.
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Myenlencephalon
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The medulla oblongta portion of the brain stem.
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Myelin
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A fatty substance that insulates axons.
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Myelin Sheaths
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Surround the dome axons of some central neurons.
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Nerve Fibers
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Long axons found in peripheral nerves that have threadlike appearance.
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Neural Tube
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Originates in the early development and is formed from a dorsal infolding of ectoderm, the outermost of the 3 embryonic cell layers.
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Nodes of Ranvier
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Sites in myelinated axon in which the sheath is interrupted at regular intervals, leaving the axonal membrane bare.
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Occipital Lobes
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The most caudal lobes that are site of primary visual area.
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Oculomotor
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The cranial nerve that contains efferents that innervate 4 of the 6 extrinsic eye muscles and parasympathetic fibers that innervate the iris of the eye.
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Oligodendrocytes
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A class of glial cell in the CNS that is responsible for laying down myelin sheaths that surround axons of some central neurons.
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Open State
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1 of 3 states a Na++ channel may exist in which the transmembrane potential and can be opened by depolarization.
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Paravertebral Chain Ganglion
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Part of the sympathetic pathway to the effectors.
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Perineurium
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A wrapping that separates fascicles from one another.
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Pia Mater
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The innermost layer of meninges that surround the whole CNS.
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Pineal Gland
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The major structure of the epithalamus that is unpaired, knoblike structure that secretes melatonin.
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Pituitary Gland
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An extremely important element of the endocrine system, projects inferiorly from the hypothalamus.
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Plexi (Plexus)
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Interlacing networks formed by the ventral rami of all spinal nerves, with the exception of T2-T12, by joining one another lateral to the vertebral column.
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Polarized
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A resting cell's membrane in which it is charged electrically with a positive and negative pole.
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Polysynaptic Withdrawal Reflex
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The reflex arc includes one or more interneurons. The withdrawal reflex is a commonly experienced polysynaptic spinal reflex that results in a generalized flexion of an appendage in response to an averse stimuli.
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Pons
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A region in the brain stem.
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Postcentral Gyrus
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The primary somatosensory area of the cortex.
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Posterior Horns (Dorsal Horns)
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Central gray matter is shaped like a capital H and the horns are the arms of the H that project posteriorly.
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Posterior Spinocerebellar Tracts
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Located within the spinocerebellar pathway, carrying information from muscle and joint receptors to the cerebellum.
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Postganglionic Neuron
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The 2nd neuron of the autonomic pathways; In peripheral ganglion, the neuron on which the preganglionic cell's axon synapses and then projects to an effector in a visceral organ.
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Postsynaptic
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In a synaptic transmission, the recipient cell.
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Postsynaptic Potential (PSP)
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Caused by the binding of transmitter to its receptor initiates a permeability change in the postsynaptic cell.
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Precentral Gyrus
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The primary motor areas of the cortex.
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Prefrontal Cortex
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Lies rostral to the motor areas of the precentral gyrus, and is important for activities that involve reasoning, complex learning abilities, long-term planning, and judgement and is also involved in mood, emotions and social behavior.
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Preganglionic Neuron
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The first neuron of the autonomic pathways; its cell body is in the CNS, and its axon projecting to a peripheral autonomic ganglion.
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Prevertebral Ganglia
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The point in which a preganglionic axon synapses on a postganglionic neuron that projects to an effector in the abdominal cavity.
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Primary Auditory Area
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Located in the temporal lobe.
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Primary Brain Vesicles
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The prosencephalon (forebrain), mesencephalon (midbrain) and rhombencephalon (hindbrain).
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Prosencephalon (Forebrain)
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1 of 3 primary brain vesicles.
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Pyramidal Tracts
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Carry axons of neurons in the motor cortex that traverse the cord without synapsing until they reach neurons in the spinal segments.
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Rami Communicate
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The medial gray ramus and the lateral white ramus that connect the base of each ventral ramus to a corresponding sympathetic chain ganglion, part of the sympathetic branch of the autonomic nervous system.
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Reflex Arc
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The organization of neurons and effectors, which is the simplest way of organizing the nervous system to achieve an appropriate response.
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Relative Refractory Period
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A period after the absolute refractory period during which a second action potential can be initiated, but the stimulus must be more intense.
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Resting Potential
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In the resting cell, the plasma membrane is mainly permeable to K+, and the inside-to-outside concentration gradient tends to drive K+ toward the outside of the cell, giving membrane a slight excess positive charge on the outer surface of the membrane and a corresponding slight excess of negative charge on the outside.
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Resting State
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A state in which closed channels could be thought of as available to be opened by depolarization.
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Rhombencephalon (Hindbrain)
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1 of 3 primary brain vesicles.
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Schwann Cells
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In the PNS, the glial cells responsible for myelinating CNS neurons.
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Somatic Region
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One region of the PNS that consists of skeletal muscles and body surface.
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Somatotopy
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The map-like organization of the brain.
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Spatial Summation
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Multiple synapses located on the same postsynaptic cell.
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Spike
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When an action potential occurs, the membrane potential changes rapidly from its resting inside-negative value to an inside-positive value (peaking typically in the range of +20 to +50mV) and just as quickly returns to the resting value.
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Spinal Nerve
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The major nerves of the spine; there are 31 pairs of spinal nerves.
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Spinal Reflexes
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The reflex arc does not include brain neurons and is typically limited to one or a few adjacent spinal segements.
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Spinocerebellar Pathway
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Carries information from muscle and joint receptors to the cerebellum.
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Spinothalamic Pathway
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Located in the anterior and lateral spinothalamic tracts, the pathway carries information about coarse touch, temperature and pain sensations to the primary somatosensory cortex.
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Splanchnic Nerve
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A nerve that a preganglionic axon can follow after passing through the chain ganglion without synapsing.
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Sulci (Sulcus)
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Shallow grooves created by folding of the cortex as it grows.
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Sympathetic Chain Ganglia
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A paired series lying parallel to the spinal column on each side and connected to the ventral rami of T1 - L1 by rami communicantes.
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Synapses
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The points of close contact between axon terminals and the target cells.
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Synaptic Cleft
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A narrow space that separates the presynaptic cell and the postsynaptic cell.
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Synaptic Delay
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Represents the time required for the presynaptic cell to organize transmitter release, for the transmitter to diffuse to receptors, and for the activated receptors to cause a PSP.
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Synaptic Fatigue
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Continual use of a particular pathway may result in depletion of the stores of the transmitter, decreasing the efficacy of the synapses.
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Synaptic Transmission
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The process of sending information across synapses.
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Synaptic Vesicles
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A small, membrane-bound vesicles that stores neurotransmitter chemicals in the axon terminal.
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Tectum
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The roof of the cerebral aqueduct that runs through the midbrain.
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Telencephalon
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In the forebrain, the cerebral cortex and basal nuclei.
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Telodendria
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Branches formed at the end of axons, ending in axon terminals.
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Temporal Lobe
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The site of the primary auditory area.
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Temporal Summation
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Several action potentials that arrive one after the other at the same synapse.
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Thalamocortical Fiber Tracts
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Relay information from the somatosensory, visual, auditory, olfactory, and gustatory sensory systems to the primary processing areas of the cortex.
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Third Ventricle
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Located in the center of the diencephalon.
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Transverse Fissure
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Separates the cerebral hemispheres from the cerebellum.
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Trigeminal
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A cranial nerve that contains afferents from the face adn innervates masticatory (chewing) muscles.
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Upstroke
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A rapid rise in the membrane potential.
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Vagus
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The only cranial nerve to extend beyond the head/neck; innervates larynx and contains afferents and parasympathetic efferents from/to thoracic and abdominal viscera.
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Ventral Horns
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Central gray matter is shaped like a capital H and the horns are the arms of the H that project anteriorly.
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Ventral Ramus
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A spinal nerve branch.
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Ventral Roots
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Each spinal segment has a pair that project from the anteriolateral surface.
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Ventricles
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A system of four interconnected spaces of the brain filled with CSF.
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Visceral Region
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One region of the PNS that consists of the soft internal organs of the digestive system, lungs, hearts, and blood vessels, etc.
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White Matter
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Forming the outer layer of the spinal cord; also the location of the cerebral basal nuclei.
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White Ramus
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The lateral branch of the rami communicante that connects the base of each ventral ramus to a corresponding sympathetic chain ganglion.
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