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JMW Nervous System
Vocab for the Nervous System
Question | Answer |
---|---|
Neuron | an electrically excitable cell that processes and transmits information by electrical and chemical signaling |
Soma | The entire body of an organism, exclusive of the germ cells. |
Dendrite | short fiber that conducts toward the cell body of the neuron |
Synapse | the junction between two neurons (axon-to-dendrite) or between a neuron and a muscle; "nerve impulses cross a synapse through the action of neurotransmitters" |
Multipolar neuron | A multipolar neuron is a type of neuron that possesses a single (usually long) axon and many dendrites, allowing for the integration of a great deal of information from other neurons. These dendritic branches can also emerge from the nerve cell body |
Bipolar neuron | A bipolar cell is a type of neuron which has two extensions. Bipolar cells are specialized sensory neurons for the transmission of special senses. As such, they are part of the sensory pathways for smell, sight, taste, hearing and vestibular functions. |
Unipolar neuron | A unipolar neuron is a type of neuron in which only one protoplasmic process (neurite) extends from the cell body. Most neurons are multipolar, generating several dendrites and an axon. |
Anaxonic neuron | A central nervous system neuron that has many processes but no apparent axon. |
Schwann Cell | any cell that covers the nerve fibers in the peripheral nervous system and forms the myelin sheath |
Myelin sheath | medullary sheath: a layer of myelin encasing (and insulating) the axons of medullated nerve fibers |
Electrical potential | called the electrostatic potential) at a point in space is electrical potential energy divided by charge that is associated with a static (time-invariant) electric field. |
Current | a flow of electricity through a conductor; "the current was measured in amperes" |
Polarized | is a property of certain types of waves that describes the orientation of their oscillations. |
Neurotransmitter | a neurochemical that transmits nerve impulses across a synapse |
Dopamine | a monoamine neurotransmitter found in the brain and essential for the normal functioning of the central nervous system; as a drug (trade names Dopastat and Intropin) it is used to treat shock and hypotension |
Serotonin | a neurotransmitter involved in e.g. sleep and depression and memory |
Somatic reflex | Any reflex in which the effectors are skeletal muscles, eg, the patellar reflex, the flexor or withdrawal reflex, the crossed extensor reflex, the plantar reflex, the abdominal reflexes, etc. |
Visceral reflex | Reflesxes within the internal organs |
Meninges | meninx: a membrane (one of 3) that envelops the brain and spinal cord |
Dura mater | the outermost (and toughest) of the 3 meninges |
Gray matter | greyish nervous tissue containing cell bodies as well as fibers; forms the cerebral cortex consisting of unmyelinated neurons |
White matter | whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths |
Cerebrum | anterior portion of the brain consisting of two hemispheres; dominant part of the brain in humans |
Cerebellum | a major division of the vertebrate brain; situated above the medulla oblongata and beneath the cerebrum in humans |
Gyrus | a convex fold or elevation in the surface of the brain |
Sulcus | (anatomy) any of the narrow grooves in an organ or tissue especially those that mark the convolutions on the surface of the brain |
Brainstem | the part of the brain continuous with the spinal cord and comprising the medulla oblongata and pons and midbrain and parts of the hypothalamus |
Cortex | cerebral cortex: the layer of unmyelinated neurons (the grey matter) forming the cortex of the cerebrum |
Blood-brain barrier | a mechanism that creates a barrier between brain tissues and circulating blood; serves to protect the central nervous system; "the brain was protected from the large molecules of the virus by the blood-brain barrier" |
Medulla oblongata | lower or hindmost part of the brain; continuous with spinal cord |
Thalamus | large egg-shaped structures of grey matter that form the dorsal subdivision of the diencephalon |
Hypothalamus | a basal part of the diencephalon governing autonomic nervous system |
Occipital lobe | that part of the cerebral cortex in either hemisphere of the brain lying in the back of the head |
Parietal lobe | that part of the cerebral cortex in either hemisphere of the brain lying below the crown of the head |
Frontal lobe | that part of the cerebral cortex in either hemisphere of the brain lying directly behind the forehead |